feat: add GITEA_DOCKER_WORKSPACE and container cleanup (#1204)

1. Add `GITEA_DOCKER_WORKSPACE` which holds the workspace path as the daemon sees it, enabling `${GITEA_DOCKER_WORKSPACE:-.}/data:/app/data` in a compose file without having to resort to `bind_workdir` (which causes much more problems like breaking `actions/cache` because of unstable workspace paths).
2. Add container/network/volume cleanup for containers started within jobs, for example via `docker compose` inside a job. It works by running a lightweight docker socket proxy and injecting a `com.gitea.runner.job` label into every container creation and that label is used to remove containers started by that job at the end. Perf impact of this is near-zero.

Docs: https://gitea.com/gitea/docs/pulls/535

Assisted by Claude (Fable 5.1).
Co-authored-by: bircni <bircni@icloud.com>
Reviewed-on: https://gitea.com/gitea/runner/pulls/1204
Reviewed-by: bircni <bircni@icloud.com>
Co-authored-by: silverwind <me@silverwind.io>

README.md

@@ -266,6 +266,17 @@ A job in a container reaches a service by its id on the job network, on the port
 
 Unlike GitHub, a job whose steps run on the host (a `host` label without `container:`) starts no service containers, so `job.services` and `job.container` stay empty. Give such a job a `container:` when it needs services.
 
+#### Docker from a job (`GITEA_DOCKER_WORKSPACE`)
+
+A container a job starts through the Docker socket cannot bind-mount the workspace by the job's own path, the daemon does not have it. `GITEA_DOCKER_WORKSPACE` holds the path the daemon sees. Use it as the prefix of workspace binds, with `.` as the fallback for local use, here in a `docker-compose.yaml`:
+
+```yaml
+volumes:
+  - ${GITEA_DOCKER_WORKSPACE:-.}/data:/app/data
+```
+
+Containers, networks and volumes a job creates through the socket are removed when the job ends. Both apply to jobs in containers, on the host `.` already works.
+
 #### Proxy
 
 Set these variables in the runner's environment, with systemd `Environment=`, `docker run -e`, or Kubernetes `env:`:

act/common/git/git.go

@@ -391,7 +391,11 @@ func NewGitCloneExecutor(input NewGitCloneExecutorInput) common.Executor {
 			}
 		}
 
-		if !isOfflineMode {
+		// A just-cloned ref is as current as a fetch would make it, and a commit hash never moves.
+		_, _, present := refRevision(r, input.Ref)
+		refresh := !isOfflineMode && (!present || (reused && !plumbing.IsHash(input.Ref)))
+
+		if refresh {
 			err = r.FetchContext(ctx, &fetchOptions)
 			if err != nil && !errors.Is(err, git.NoErrAlreadyUpToDate) {
 				return err
@@ -411,23 +415,7 @@ func NewGitCloneExecutor(input NewGitCloneExecutorInput) common.Executor {
 			}
 		}
 
-		// At this point we need to know if it's a tag or a branch
-		// And the easiest way to do it is duck typing
-		//
-		// If err is nil, it's a tag so let's proceed with that hash like we would if
-		// it was a sha
-		refType := "tag"
-		rev = plumbing.Revision(path.Join("refs", "tags", input.Ref))
-		if _, err := r.Tag(input.Ref); errors.Is(err, git.ErrTagNotFound) {
-			rName := plumbing.ReferenceName(path.Join("refs", "remotes", "origin", input.Ref))
-			if _, err := r.Reference(rName, false); errors.Is(err, plumbing.ErrReferenceNotFound) {
-				refType = "sha"
-				rev = plumbing.Revision(input.Ref)
-			} else {
-				refType = "branch"
-				rev = plumbing.Revision(rName)
-			}
-		}
+		rev, refType, _ := refRevision(r, input.Ref)
 
 		if hash, err = r.ResolveRevision(rev); err != nil {
 			logger.Errorf("Unable to resolve %s: %v", input.Ref, err)
@@ -459,7 +447,7 @@ func NewGitCloneExecutor(input NewGitCloneExecutorInput) common.Executor {
 		reusedMsg := ""
 
 		switch {
-		case !isOfflineMode && !shallow:
+		case refresh && !shallow:
 			// In shallow mode the depth-limited fetch above already advanced the ref.
 			if err = w.PullContext(ctx, &pullOptions); err != nil && !errors.Is(err, git.NoErrAlreadyUpToDate) {
 				logger.Debugf("Unable to pull %s: %v", refName, err)
@@ -501,27 +489,37 @@ func NewGitCloneExecutor(input NewGitCloneExecutorInput) common.Executor {
 	}
 }
 
-// cloneAtDepth clones input.URL into input.Dir using opts.
-// With input.Depth > 0 it first tries a shallow, single-branch clone of input.Ref, falling back when error.
+// cloneAtDepth falls back to a full clone when the shallow attempt fails.
 func cloneAtDepth(ctx context.Context, input NewGitCloneExecutorInput, opts git.CloneOptions, logger log.FieldLogger) (*git.Repository, error) {
 	if input.Depth > 0 {
-		for _, refName := range []plumbing.ReferenceName{
-			plumbing.NewBranchReferenceName(input.Ref),
-			plumbing.NewTagReferenceName(input.Ref),
-		} {
-			shallowOpts := opts
-			shallowOpts.Depth = input.Depth
-			shallowOpts.SingleBranch = true
-			shallowOpts.ReferenceName = refName
-			shallowOpts.Tags = git.NoTags
-
-			r, err := git.PlainCloneContext(ctx, input.Dir, false, &shallowOpts)
+		if plumbing.IsHash(input.Ref) {
+			r, err := fetchPinnedSHA(ctx, input, opts)
 			if err == nil {
 				return r, nil
 			}
-			logger.Debugf("Shallow clone of %s as %s failed: %v", input.URL, refName, err)
-			if rmErr := os.RemoveAll(input.Dir); rmErr != nil {
-				return nil, fmt.Errorf("remove partial clone %s: %w", input.Dir, rmErr)
+			logger.Debugf("Shallow fetch of %s at %s failed: %v", input.URL, input.Ref, err)
+			if err := removePartialClone(input.Dir); err != nil {
+				return nil, err
+			}
+		} else {
+			for _, refName := range []plumbing.ReferenceName{
+				plumbing.NewBranchReferenceName(input.Ref),
+				plumbing.NewTagReferenceName(input.Ref),
+			} {
+				shallowOpts := opts
+				shallowOpts.Depth = input.Depth
+				shallowOpts.SingleBranch = true
+				shallowOpts.ReferenceName = refName
+				shallowOpts.Tags = git.NoTags
+
+				r, err := git.PlainCloneContext(ctx, input.Dir, false, &shallowOpts)
+				if err == nil {
+					return r, nil
+				}
+				logger.Debugf("Shallow clone of %s as %s failed: %v", input.URL, refName, err)
+				if err := removePartialClone(input.Dir); err != nil {
+					return nil, err
+				}
 			}
 		}
 		logger.Debugf("Falling back to a full clone of %s for ref %q", input.URL, input.Ref)
@@ -530,14 +528,65 @@ func cloneAtDepth(ctx context.Context, input NewGitCloneExecutorInput, opts git.
 	return git.PlainCloneContext(ctx, input.Dir, false, &opts)
 }
 
+func removePartialClone(dir string) error {
+	if err := os.RemoveAll(dir); err != nil {
+		return fmt.Errorf("remove partial clone %s: %w", dir, err)
+	}
+	return nil
+}
+
+func fetchPinnedSHA(ctx context.Context, input NewGitCloneExecutorInput, opts git.CloneOptions) (*git.Repository, error) {
+	r, err := git.PlainInit(input.Dir, false)
+	if err != nil {
+		return nil, err
+	}
+	if _, err := r.CreateRemote(&config.RemoteConfig{Name: "origin", URLs: []string{input.URL}}); err != nil {
+		return nil, err
+	}
+	if err := r.FetchContext(ctx, &git.FetchOptions{
+		RefSpecs:        []config.RefSpec{pinnedRefSpec(input.Ref)},
+		Depth:           input.Depth,
+		Tags:            git.NoTags,
+		Auth:            opts.Auth,
+		Progress:        opts.Progress,
+		InsecureSkipTLS: opts.InsecureSkipTLS,
+	}); err != nil {
+		return nil, err
+	}
+	return r, nil
+}
+
+// pinnedRefSpec keeps a hash-shaped name out of refs/heads and refs/tags.
+func pinnedRefSpec(sha string) config.RefSpec {
+	return config.RefSpec(fmt.Sprintf("+%s:refs/pinned/%s", sha, sha))
+}
+
+// refRevision picks the revision to check out and reports whether it resolves locally.
+func refRevision(r *git.Repository, ref string) (plumbing.Revision, string, bool) {
+	if plumbing.IsHash(ref) {
+		// git ignores a ref named as 40 hex digits, so a full hash always denotes the commit itself.
+		_, err := r.CommitObject(plumbing.NewHash(ref))
+		return plumbing.Revision(ref), "sha", err == nil
+	}
+	if _, err := r.Tag(ref); err == nil {
+		return plumbing.Revision(path.Join("refs", "tags", ref)), "tag", true
+	}
+	remoteRef := plumbing.ReferenceName(path.Join("refs", "remotes", "origin", ref))
+	if _, err := r.Reference(remoteRef, false); err == nil {
+		return plumbing.Revision(remoteRef), "branch", true
+	}
+	rev := plumbing.Revision(ref)
+	_, err := r.ResolveRevision(rev)
+	return rev, "sha", err == nil
+}
+
 // isShallow reports whether the local repository was cloned with a limited depth.
 func isShallow(r *git.Repository) bool {
 	shallows, err := r.Storer.Shallow()
 	return err == nil && len(shallows) > 0
 }
 
-// shallowFetchRefSpec returns the single refspec that updates only input.Ref, keeping a shallow clone from re-downloading every branch's history.
-// ok is false when the ref is not present locally as a tag or remote-tracking branch, in which case the broad default refspec is used.
+// shallowFetchRefSpec limits a shallow update to the requested ref, falling back to the broad refspec when it is not present locally.
 func shallowFetchRefSpec(r *git.Repository, ref string) (config.RefSpec, bool) {
 	tagRef := plumbing.NewTagReferenceName(ref)
 	if _, err := r.Reference(tagRef, false); err == nil {
@@ -548,5 +597,9 @@ func shallowFetchRefSpec(r *git.Repository, ref string) (config.RefSpec, bool) {
 		branchRef := plumbing.NewBranchReferenceName(ref)
 		return config.RefSpec(fmt.Sprintf("+%s:%s", branchRef, remoteRef)), true
 	}
+	if plumbing.IsHash(ref) {
+		// The broad refspec carries only advertised tips, never a pinned commit.
+		return pinnedRefSpec(ref), true
+	}
 	return "", false
 }

act/common/git/git_test.go

@@ -16,6 +16,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"syscall"
 	"testing"
 	"time"
@@ -24,6 +25,9 @@ import (
 
 	gogit "github.com/go-git/go-git/v5"
 	gogitconfig "github.com/go-git/go-git/v5/config"
+	"github.com/go-git/go-git/v5/plumbing/transport"
+	gogitclient "github.com/go-git/go-git/v5/plumbing/transport/client"
+	gogitfile "github.com/go-git/go-git/v5/plumbing/transport/file"
 	log "github.com/sirupsen/logrus"
 	logrustest "github.com/sirupsen/logrus/hooks/test"
 	"github.com/stretchr/testify/assert"
@@ -435,7 +439,7 @@ func TestGitCloneExecutorShallow(t *testing.T) {
 		require.NoError(t, gitCmd("-C", workDir, "commit", "--allow-empty", "-m", m))
 	}
 	require.NoError(t, gitCmd("-C", workDir, "tag", "v1"))
-	sha := gitRevParse(t, workDir, "HEAD~1") // c2, a SHA that go-git cannot shallow-clone
+	unadvertisedSHA := gitRevParse(t, workDir, "HEAD~1")
 	require.NoError(t, gitCmd("-C", workDir, "push", "-u", "origin", "main"))
 	require.NoError(t, gitCmd("-C", workDir, "push", "origin", "v1"))
 
@@ -461,14 +465,43 @@ func TestGitCloneExecutorShallow(t *testing.T) {
 		assert.Equal(t, "c3", gitHeadSubject(t, dir))
 	})
 
-	t.Run("SHA falls back to a full clone", func(t *testing.T) {
+	unadvertisedRemote := func(t *testing.T, allowUnadvertised bool) string {
+		remote := filepath.Join(t.TempDir(), "remote.git")
+		require.NoError(t, gitCmd("clone", "--bare", remoteDir, remote))
+		require.NoError(t, gitCmd("-C", remote, "config", "uploadpack.allowAnySHA1InWant", strconv.FormatBool(allowUnadvertised)))
+		return remote
+	}
+
+	t.Run("commit hash falls back to a full clone when the remote refuses unadvertised objects", func(t *testing.T) {
 		dir := t.TempDir()
 		require.NoError(t, NewGitCloneExecutor(NewGitCloneExecutorInput{
-			URL: remoteDir, Ref: sha, Dir: dir, Depth: 1,
+			URL: unadvertisedRemote(t, false), Ref: unadvertisedSHA, Dir: dir, Depth: 1,
 		})(t.Context()))
-		// go-git cannot shallow-clone a raw SHA, so it falls back to a full clone; the absence of a shallow marker proves the fallback happened.
-		assert.NoFileExists(t, shallowMarker(dir), "a SHA ref must not produce a shallow clone")
-		assert.Equal(t, sha, gitRevParse(t, dir, "HEAD"))
+		assert.NoFileExists(t, shallowMarker(dir))
+		assert.Equal(t, unadvertisedSHA, gitRevParse(t, dir, "HEAD"))
+	})
+
+	t.Run("commit hash is fetched shallowly, moved to another hash, then reused without reaching the remote", func(t *testing.T) {
+		remote := unadvertisedRemote(t, true)
+		dir := t.TempDir()
+		cloneAt := func(ref string) error {
+			return NewGitCloneExecutor(NewGitCloneExecutorInput{
+				URL: remote, Ref: ref, Dir: dir, Depth: 1,
+			})(t.Context())
+		}
+
+		require.NoError(t, cloneAt(unadvertisedSHA))
+		assert.FileExists(t, shallowMarker(dir))
+		assert.Equal(t, 1, gitRevCount(t, dir))
+		assert.Equal(t, unadvertisedSHA, gitRevParse(t, dir, "HEAD"))
+
+		olderSHA := gitRevParse(t, workDir, "HEAD~2")
+		require.NoError(t, cloneAt(olderSHA))
+		assert.Equal(t, olderSHA, gitRevParse(t, dir, "HEAD"))
+
+		require.NoError(t, os.RemoveAll(remote))
+		require.NoError(t, cloneAt(olderSHA))
+		assert.Equal(t, olderSHA, gitRevParse(t, dir, "HEAD"))
 	})
 
 	t.Run("moving branch updates while staying shallow", func(t *testing.T) {
@@ -491,6 +524,77 @@ func TestGitCloneExecutorShallow(t *testing.T) {
 	})
 }
 
+func TestGitCloneExecutorColdCloneSkipsRefresh(t *testing.T) {
+	remoteDir := t.TempDir()
+	require.NoError(t, gitCmd("init", "--bare", "--initial-branch=main", remoteDir))
+	workDir := t.TempDir()
+	require.NoError(t, gitCmd("clone", remoteDir, workDir))
+	require.NoError(t, gitCmd("-C", workDir, "checkout", "-b", "main"))
+	require.NoError(t, gitCmd("-C", workDir, "commit", "--allow-empty", "-m", "c1"))
+	require.NoError(t, gitCmd("-C", workDir, "tag", "v1"))
+	require.NoError(t, gitCmd("-C", workDir, "push", "-u", "origin", "main"))
+	require.NoError(t, gitCmd("-C", workDir, "push", "origin", "v1"))
+
+	for name, tt := range map[string]struct {
+		Ref   string
+		Depth int
+	}{
+		"shallow branch": {"main", 1},
+		"full clone tag": {"v1", 0},
+	} {
+		t.Run(name, func(t *testing.T) {
+			counter := installCountingTransport(t)
+			require.NoError(t, NewGitCloneExecutor(NewGitCloneExecutorInput{
+				URL: remoteDir, Ref: tt.Ref, Dir: t.TempDir(), Depth: tt.Depth,
+			})(t.Context()))
+			assert.Equal(t, int64(1), counter.sessions.Load())
+		})
+	}
+}
+
+func TestGitCloneExecutorPinnedHashIgnoresShadowingRef(t *testing.T) {
+	remoteDir := t.TempDir()
+	require.NoError(t, gitCmd("init", "--bare", "--initial-branch=main", remoteDir))
+	workDir := t.TempDir()
+	require.NoError(t, gitCmd("clone", remoteDir, workDir))
+	require.NoError(t, gitCmd("-C", workDir, "checkout", "-b", "main"))
+	require.NoError(t, gitCmd("-C", workDir, "commit", "--allow-empty", "-m", "pinned"))
+	pinned := gitRevParse(t, workDir, "HEAD")
+	require.NoError(t, gitCmd("-C", workDir, "commit", "--allow-empty", "-m", "decoy"))
+	require.NoError(t, gitCmd("-C", workDir, "tag", pinned))
+	require.NoError(t, gitCmd("-C", workDir, "push", "-u", "origin", "main"))
+	require.NoError(t, gitCmd("-C", workDir, "push", "origin", pinned))
+
+	for name, depth := range map[string]int{"shallow": 1, "full clone": 0} {
+		t.Run(name, func(t *testing.T) {
+			dir := t.TempDir()
+			require.NoError(t, NewGitCloneExecutor(NewGitCloneExecutorInput{
+				URL: remoteDir, Ref: pinned, Dir: dir, Depth: depth,
+			})(t.Context()))
+			assert.Equal(t, pinned, gitRevParse(t, dir, "HEAD"))
+		})
+	}
+}
+
+type countingTransport struct {
+	transport.Transport
+	sessions atomic.Int64
+}
+
+func (c *countingTransport) NewUploadPackSession(ep *transport.Endpoint, auth transport.AuthMethod) (transport.UploadPackSession, error) {
+	c.sessions.Add(1)
+	return c.Transport.NewUploadPackSession(ep, auth)
+}
+
+func installCountingTransport(t *testing.T) *countingTransport {
+	t.Helper()
+	counter := &countingTransport{Transport: gogitfile.DefaultClient}
+	gogitclient.InstallProtocol("file", counter)
+	t.Cleanup(func() { gogitclient.InstallProtocol("file", gogitfile.DefaultClient) })
+
+	return counter
+}
+
 func gitRevParse(t *testing.T, dir, rev string) string {
 	t.Helper()
 	out, err := exec.Command("git", "-C", dir, "rev-parse", rev).Output()

act/container/container_types.go

@@ -75,6 +75,17 @@ const (
 // fragment, missingContainerError composes it into the message every operation shares.
 var ErrContainerNotFound = errors.New("does not exist")
 
+// DockerProxy is a job's docker socket, fronting the daemon's for the job's lifetime.
+type DockerProxy struct {
+	Socket string
+	close  func(context.Context) error
+}
+
+// Close removes what the job created through the socket, then stops serving it.
+func (p *DockerProxy) Close(ctx context.Context) error {
+	return p.close(ctx)
+}
+
 // Info is a snapshot of a container, as of one inspect.
 type Info struct {
 	ID       string
@@ -84,13 +95,14 @@ type Info struct {
 	// HealthOutput is the last healthcheck probe's output.
 	HealthOutput string
 	Ports        map[string]string // container port ("5432") to the host port it is published on
+	Mounts       map[string]string // container path to its source on the daemon
 }
 
 // Container for managing docker run containers
 type Container interface {
 	Create(capAdd, capDrop []string) common.Executor
 	Copy(destPath string, files ...*FileEntry) common.Executor
-	CopyDir(destPath, srcPath string, useGitIgnore bool) common.Executor
+	CopyDir(destPath, srcPath string, useGitIgnore, skipGitDir bool) common.Executor
 	GetContainerArchive(ctx context.Context, srcPath string) (io.ReadCloser, error)
 	Inspect(ctx context.Context) (*Info, error)
 	DumpLogs(ctx context.Context) error

act/container/docker_proxy.go

@@ -0,0 +1,276 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+//go:build !(WITHOUT_DOCKER || !(linux || darwin || windows || netbsd))
+
+package container
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"sync"
+	"time"
+
+	"gitea.com/gitea/runner/act/common"
+
+	cerrdefs "github.com/containerd/errdefs"
+	"github.com/moby/moby/api/types/container"
+	"github.com/moby/moby/api/types/mount"
+	"github.com/moby/moby/client"
+)
+
+const (
+	jobLabel      = "com.gitea.runner.job"
+	maxCreateBody = 8 << 20
+)
+
+var (
+	createPath    = regexp.MustCompile(`^(/v[0-9.]+)?/(containers|networks|volumes)/create$`)
+	rawStreamPath = regexp.MustCompile(`^(/v[0-9.]+)?/(containers/[^/]+/attach|exec/[^/]+/start)$`)
+	proxyProbe    struct {
+		sync.Mutex
+		decided bool
+		dir     string
+	}
+)
+
+// DockerProxyDir returns where job proxy sockets live, "" while undecided or when the daemon cannot open the runner's files.
+func DockerProxyDir(ctx context.Context) string {
+	proxyProbe.Lock()
+	defer proxyProbe.Unlock()
+	if proxyProbe.decided {
+		return proxyProbe.dir
+	}
+	dir := filepath.Join(os.TempDir(), "gitea-runner-docker")
+	ok, err := daemonSeesDir(ctx, dir)
+	if err != nil {
+		common.Logger(ctx).Debugf("docker proxy probe postponed: %v", err)
+		return ""
+	}
+	proxyProbe.decided = true
+	if ok {
+		proxyProbe.dir = dir
+	} else {
+		common.Logger(ctx).Infof("the docker daemon cannot reach the runner's filesystem, jobs get the daemon socket directly")
+	}
+	return proxyProbe.dir
+}
+
+func daemonSeesDir(ctx context.Context, dir string) (bool, error) {
+	if err := os.MkdirAll(dir, 0o700); err != nil {
+		return false, err
+	}
+	probe := filepath.Join(dir, "probe")
+	if err := os.WriteFile(probe, nil, 0o600); err != nil {
+		return false, err
+	}
+	cli, err := GetDockerClient(ctx)
+	if err != nil {
+		return false, err
+	}
+	defer cli.Close()
+	images, err := cli.ImageList(ctx, client.ImageListOptions{})
+	if err != nil {
+		return false, err
+	}
+	if len(images.Items) == 0 {
+		return false, errors.New("no image to probe with yet")
+	}
+	// creating validates that a bind source exists on the daemon's side, nothing is started
+	created, err := cli.ContainerCreate(ctx, client.ContainerCreateOptions{
+		Config:     &container.Config{Image: images.Items[0].ID, Cmd: []string{"true"}},
+		HostConfig: &container.HostConfig{Mounts: []mount.Mount{{Type: mount.TypeBind, Source: probe, Target: "/gitea-runner-probe"}}},
+	})
+	if cerrdefs.IsInvalidArgument(err) {
+		return false, nil
+	}
+	if err != nil {
+		return false, err
+	}
+	_, err = cli.ContainerRemove(ctx, created.ID, client.ContainerRemoveOptions{Force: true})
+	return true, err
+}
+
+// StartDockerProxy serves a job's docker socket in dir, labelling what the job creates through it.
+func StartDockerProxy(daemonSocket, dir, job string) (*DockerProxy, error) {
+	if err := os.MkdirAll(dir, 0o700); err != nil {
+		return nil, err
+	}
+	digest := sha256.Sum256([]byte(job))
+	socket := filepath.Join(dir, hex.EncodeToString(digest[:8])+".sock")
+	_ = os.Remove(socket)
+	listener, err := net.Listen("unix", socket)
+	if err != nil {
+		return nil, err
+	}
+	if info, err := os.Stat(daemonSocket); err == nil {
+		_ = os.Chmod(socket, info.Mode().Perm())
+	}
+	dial := func(ctx context.Context, _, _ string) (net.Conn, error) {
+		return (&net.Dialer{}).DialContext(ctx, "unix", daemonSocket)
+	}
+	transport := &http.Transport{DialContext: dial}
+	forward := &httputil.ReverseProxy{
+		Rewrite: func(r *httputil.ProxyRequest) {
+			r.Out.URL.Scheme = "http"
+			r.Out.URL.Host = "docker"
+		},
+		Transport: transport,
+	}
+	server := &http.Server{ReadHeaderTimeout: 30 * time.Second, Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case r.Method != http.MethodPost:
+		case createPath.MatchString(r.URL.Path):
+			if err := addLabel(r, job); err != nil {
+				http.Error(w, err.Error(), http.StatusBadRequest)
+				return
+			}
+		case rawStreamPath.MatchString(r.URL.Path):
+			tunnel(w, r, dial)
+			return
+		}
+		forward.ServeHTTP(w, r)
+	})}
+	go func() { _ = server.Serve(listener) }()
+	return &DockerProxy{Socket: socket, close: func(ctx context.Context) error {
+		err := removeJobResources(ctx, job)
+		_ = server.Close()
+		transport.CloseIdleConnections()
+		_ = os.Remove(socket)
+		return err
+	}}, nil
+}
+
+func addLabel(r *http.Request, job string) error {
+	body, err := io.ReadAll(io.LimitReader(r.Body, maxCreateBody+1))
+	if err != nil {
+		return err
+	}
+	if len(body) > maxCreateBody {
+		return errors.New("create request too large")
+	}
+	if len(bytes.TrimSpace(body)) == 0 {
+		r.Body = io.NopCloser(bytes.NewReader(body))
+		return nil
+	}
+	var fields map[string]json.RawMessage
+	if err := json.Unmarshal(body, &fields); err != nil {
+		return fmt.Errorf("invalid create request: %w", err)
+	}
+	key := "Labels"
+	for name := range fields {
+		if strings.EqualFold(name, key) {
+			key = name
+			break
+		}
+	}
+	labels := map[string]string{}
+	if raw := fields[key]; len(raw) > 0 && string(raw) != "null" {
+		if err := json.Unmarshal(raw, &labels); err != nil {
+			return fmt.Errorf("invalid create request: %w", err)
+		}
+	}
+	labels[jobLabel] = job
+	if fields[key], err = json.Marshal(labels); err != nil {
+		return err
+	}
+	if body, err = json.Marshal(fields); err != nil {
+		return err
+	}
+	r.Body = io.NopCloser(bytes.NewReader(body))
+	r.ContentLength = int64(len(body))
+	r.TransferEncoding = nil
+	return nil
+}
+
+// tunnel splices attach and exec streams, which the daemon hijacks with or without an HTTP upgrade
+func tunnel(w http.ResponseWriter, r *http.Request, dial func(context.Context, string, string) (net.Conn, error)) {
+	hijacker, ok := w.(http.Hijacker)
+	if !ok {
+		http.Error(w, "connection cannot be hijacked", http.StatusInternalServerError)
+		return
+	}
+	upstream, err := dial(r.Context(), "", "")
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadGateway)
+		return
+	}
+	defer upstream.Close()
+	if err := r.Write(upstream); err != nil {
+		http.Error(w, err.Error(), http.StatusBadGateway)
+		return
+	}
+	downstream, buffered, err := hijacker.Hijack()
+	if err != nil {
+		return
+	}
+	defer downstream.Close()
+	if _, err := io.CopyN(upstream, buffered, int64(buffered.Reader.Buffered())); err != nil {
+		return
+	}
+	done := make(chan struct{}, 2)
+	go func() {
+		_, _ = io.Copy(upstream, downstream)
+		done <- struct{}{}
+	}()
+	go func() {
+		_, _ = io.Copy(downstream, upstream)
+		done <- struct{}{}
+	}()
+	<-done
+}
+
+func removeJobResources(ctx context.Context, job string) error {
+	cli, err := GetDockerClient(ctx)
+	if err != nil {
+		return err
+	}
+	defer cli.Close()
+	return removeLabelled(ctx, cli, job)
+}
+
+func removeLabelled(ctx context.Context, cli client.APIClient, job string) error {
+	logger := common.Logger(ctx)
+	filters := make(client.Filters).Add("label", jobLabel+"="+job)
+	containers, err := cli.ContainerList(ctx, client.ContainerListOptions{All: true, Filters: filters})
+	if err != nil {
+		return err
+	}
+	var errs []error
+	for _, c := range containers.Items {
+		logger.Infof("removing container %s the job left behind", strings.TrimPrefix(strings.Join(c.Names, ","), "/"))
+		errs = append(errs, (&containerReference{cli: cli, id: c.ID}).remove()(ctx))
+	}
+	networks, err := cli.NetworkList(ctx, client.NetworkListOptions{Filters: filters})
+	if err != nil {
+		return errors.Join(append(errs, err)...)
+	}
+	for _, n := range networks.Items {
+		if _, err := cli.NetworkRemove(ctx, n.ID, client.NetworkRemoveOptions{}); err != nil && !cerrdefs.IsNotFound(err) {
+			errs = append(errs, fmt.Errorf("failed to remove network %s: %w", n.Name, err))
+		}
+	}
+	volumes, err := cli.VolumeList(ctx, client.VolumeListOptions{Filters: filters})
+	if err != nil {
+		return errors.Join(append(errs, err)...)
+	}
+	for _, v := range volumes.Items {
+		if _, err := cli.VolumeRemove(ctx, v.Name, client.VolumeRemoveOptions{}); err != nil && !cerrdefs.IsNotFound(err) {
+			errs = append(errs, fmt.Errorf("failed to remove volume %s: %w", v.Name, err))
+		}
+	}
+	return errors.Join(errs...)
+}

act/container/docker_proxy_test.go

@@ -0,0 +1,270 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+//go:build !(WITHOUT_DOCKER || !(linux || darwin || windows || netbsd))
+
+package container
+
+import (
+	"archive/tar"
+	"bufio"
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"net"
+	"net/http"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	cerrdefs "github.com/containerd/errdefs"
+	"github.com/moby/moby/api/types/container"
+	"github.com/moby/moby/api/types/network"
+	"github.com/moby/moby/api/types/volume"
+	mobyclient "github.com/moby/moby/client"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+)
+
+func (m *mockDockerClient) VolumeList(ctx context.Context, opts mobyclient.VolumeListOptions) (mobyclient.VolumeListResult, error) {
+	args := m.Called(ctx, opts)
+	return args.Get(0).(mobyclient.VolumeListResult), args.Error(1)
+}
+
+func (m *mockDockerClient) VolumeRemove(ctx context.Context, id string, opts mobyclient.VolumeRemoveOptions) (mobyclient.VolumeRemoveResult, error) {
+	args := m.Called(ctx, id, opts)
+	return args.Get(0).(mobyclient.VolumeRemoveResult), args.Error(1)
+}
+
+// unix socket paths are limited to about a hundred bytes, which the default macOS TMPDIR exceeds
+func shortTempDir(t testing.TB) string {
+	t.Helper()
+	t.Setenv("TMPDIR", "/tmp")
+	return t.TempDir()
+}
+
+func daemonSocketPath(t testing.TB, cli mobyclient.APIClient) string {
+	t.Helper()
+	host := cli.DaemonHost()
+	if !strings.HasPrefix(host, "unix://") {
+		t.Skipf("skipping: daemon at %s is not a unix socket", host)
+	}
+	return strings.TrimPrefix(host, "unix://")
+}
+
+func TestDockerProxy(t *testing.T) {
+	bodies := make(chan []byte, 8)
+	daemonSocket := filepath.Join(shortTempDir(t), "d.sock")
+	listener, err := net.Listen("unix", daemonSocket)
+	require.NoError(t, err)
+	daemon := &http.Server{ReadHeaderTimeout: time.Second, Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case strings.HasSuffix(r.URL.Path, "/create"):
+			body, _ := io.ReadAll(r.Body)
+			bodies <- body
+			w.WriteHeader(http.StatusCreated)
+		case strings.HasSuffix(r.URL.Path, "/start"):
+			conn, buffered, err := w.(http.Hijacker).Hijack()
+			if err != nil {
+				return
+			}
+			defer conn.Close()
+			_, _ = conn.Write([]byte("HTTP/1.1 200 OK\r\nContent-Type: application/vnd.docker.raw-stream\r\n\r\n"))
+			_, _ = io.Copy(conn, buffered)
+		default:
+			w.Header().Set("Api-Version", "1.47")
+			_, _ = w.Write([]byte("OK " + r.Method + " " + r.URL.Path))
+		}
+	})}
+	go func() { _ = daemon.Serve(listener) }()
+	t.Cleanup(func() { _ = daemon.Close() })
+	proxy, err := StartDockerProxy(daemonSocket, shortTempDir(t), "job-1")
+	require.NoError(t, err)
+	client := &http.Client{Transport: &http.Transport{DialContext: func(ctx context.Context, _, _ string) (net.Conn, error) {
+		return (&net.Dialer{}).DialContext(ctx, "unix", proxy.Socket)
+	}}}
+
+	t.Run("labels creates", func(t *testing.T) {
+		for path, body := range map[string]string{
+			"/v1.47/containers/create": `{"Image":"alpine","Labels":{"own":"1"}}`,
+			"/networks/create":         `{"Name":"n"}`,
+			"/volumes/create":          `{"Name":"v","labels":null}`,
+		} {
+			resp, err := client.Post("http://docker"+path, "application/json", strings.NewReader(body))
+			require.NoError(t, err)
+			resp.Body.Close()
+			assert.Equal(t, http.StatusCreated, resp.StatusCode)
+
+			var got map[string]json.RawMessage
+			require.NoError(t, json.Unmarshal(<-bodies, &got))
+			key := "Labels"
+			if _, ok := got["labels"]; ok {
+				key = "labels"
+			}
+			var labels map[string]string
+			require.NoError(t, json.Unmarshal(got[key], &labels))
+			assert.Equal(t, "job-1", labels[jobLabel], path)
+			if strings.Contains(body, "own") {
+				assert.Equal(t, "1", labels["own"])
+				assert.JSONEq(t, `"alpine"`, string(got["Image"]))
+			}
+		}
+	})
+
+	t.Run("passes other requests through", func(t *testing.T) {
+		resp, err := client.Get("http://docker/v1.47/_ping")
+		require.NoError(t, err)
+		defer resp.Body.Close()
+		body, _ := io.ReadAll(resp.Body)
+		assert.Equal(t, "1.47", resp.Header.Get("Api-Version"))
+		assert.Equal(t, "OK GET /v1.47/_ping", string(body))
+	})
+
+	t.Run("tunnels raw streams", func(t *testing.T) {
+		conn, err := net.Dial("unix", proxy.Socket)
+		require.NoError(t, err)
+		defer conn.Close()
+		_, err = conn.Write([]byte("POST /v1.47/exec/abc/start HTTP/1.1\r\nHost: docker\r\nContent-Length: 2\r\n\r\n{}ping\n"))
+		require.NoError(t, err)
+		reader := bufio.NewReader(conn)
+		resp, err := http.ReadResponse(reader, nil)
+		require.NoError(t, err)
+		defer resp.Body.Close()
+		assert.Equal(t, "application/vnd.docker.raw-stream", resp.Header.Get("Content-Type"))
+		echoed, err := reader.ReadString('\n')
+		require.NoError(t, err)
+		assert.Equal(t, "{}ping\n", echoed)
+	})
+}
+
+func TestRemoveLabelledRemovesContainersNetworksAndVolumes(t *testing.T) {
+	ctx := context.Background()
+	filters := make(mobyclient.Filters).Add("label", jobLabel+"=job-1")
+	cli := &mockDockerClient{}
+	cli.On("ContainerList", ctx, mobyclient.ContainerListOptions{All: true, Filters: filters}).
+		Return(mobyclient.ContainerListResult{Items: []container.Summary{{ID: "c1", Names: []string{"/app"}}}}, nil)
+	cli.On("ContainerKill", ctx, "c1", mock.Anything).Return(mobyclient.ContainerKillResult{}, nil)
+	cli.On("ContainerRemove", ctx, "c1", mobyclient.ContainerRemoveOptions{RemoveVolumes: true, Force: true}).
+		Return(mobyclient.ContainerRemoveResult{}, nil)
+	cli.On("NetworkList", ctx, mobyclient.NetworkListOptions{Filters: filters}).
+		Return(mobyclient.NetworkListResult{Items: []network.Summary{{ID: "n1", Name: "app_default"}}}, nil)
+	cli.On("NetworkRemove", ctx, "n1", mock.Anything).Return(mobyclient.NetworkRemoveResult{}, nil)
+	cli.On("VolumeList", ctx, mobyclient.VolumeListOptions{Filters: filters}).
+		Return(mobyclient.VolumeListResult{Items: []volume.Volume{{Name: "app_data"}}}, nil)
+	cli.On("VolumeRemove", ctx, "app_data", mobyclient.VolumeRemoveOptions{}).Return(mobyclient.VolumeRemoveResult{}, nil)
+
+	require.NoError(t, removeLabelled(ctx, cli, "job-1"))
+	cli.AssertExpectations(t)
+}
+
+func TestDockerProxyWithDaemon(t *testing.T) {
+	requireDocker(t)
+	ctx := context.Background()
+	require.NoError(t, NewDockerPullExecutor(NewDockerPullExecutorInput{Image: "alpine"})(ctx))
+	direct, err := GetDockerClient(ctx)
+	require.NoError(t, err)
+	defer direct.Close()
+	dir := shortTempDir(t)
+	seen, err := daemonSeesDir(ctx, dir)
+	require.NoError(t, err)
+	t.Logf("daemon sees the runner's filesystem: %v", seen)
+
+	job := "proxy-test-" + t.Name()
+	proxy, err := StartDockerProxy(daemonSocketPath(t, direct), dir, job)
+	require.NoError(t, err)
+	viaProxy, err := mobyclient.New(mobyclient.WithHost("unix://" + proxy.Socket))
+	require.NoError(t, err)
+	defer viaProxy.Close()
+
+	created, err := viaProxy.ContainerCreate(ctx, mobyclient.ContainerCreateOptions{
+		Config: &container.Config{Image: "alpine", Cmd: []string{"sleep", "300"}, Labels: map[string]string{"own": "1"}},
+	})
+	require.NoError(t, err)
+	t.Cleanup(func() { _, _ = direct.ContainerRemove(ctx, created.ID, mobyclient.ContainerRemoveOptions{Force: true}) })
+	_, err = viaProxy.ContainerStart(ctx, created.ID, mobyclient.ContainerStartOptions{})
+	require.NoError(t, err)
+	net, err := viaProxy.NetworkCreate(ctx, job, mobyclient.NetworkCreateOptions{})
+	require.NoError(t, err)
+	t.Cleanup(func() { _, _ = direct.NetworkRemove(ctx, net.ID, mobyclient.NetworkRemoveOptions{}) })
+	_, err = viaProxy.VolumeCreate(ctx, mobyclient.VolumeCreateOptions{Name: job})
+	require.NoError(t, err)
+	t.Cleanup(func() { _, _ = direct.VolumeRemove(ctx, job, mobyclient.VolumeRemoveOptions{Force: true}) })
+
+	inspected, err := direct.ContainerInspect(ctx, created.ID, mobyclient.ContainerInspectOptions{})
+	require.NoError(t, err)
+	assert.Equal(t, map[string]string{"own": "1", jobLabel: job}, inspected.Container.Config.Labels)
+	vol, err := direct.VolumeInspect(ctx, job, mobyclient.VolumeInspectOptions{})
+	require.NoError(t, err)
+	assert.Equal(t, job, vol.Volume.Labels[jobLabel])
+
+	exec, err := viaProxy.ExecCreate(ctx, created.ID, mobyclient.ExecCreateOptions{Cmd: []string{"cat"}, AttachStdin: true, AttachStdout: true, TTY: true})
+	require.NoError(t, err)
+	attached, err := viaProxy.ExecAttach(ctx, exec.ID, mobyclient.ExecAttachOptions{TTY: true})
+	require.NoError(t, err)
+	_, err = attached.Conn.Write([]byte("hello\n"))
+	require.NoError(t, err)
+	echoed, err := attached.Reader.ReadString('\n')
+	require.NoError(t, err)
+	assert.Equal(t, "hello\r\n", echoed)
+	attached.Close()
+
+	require.NoError(t, proxy.Close(ctx))
+	_, err = direct.ContainerInspect(ctx, created.ID, mobyclient.ContainerInspectOptions{})
+	assert.True(t, cerrdefs.IsNotFound(err))
+	_, err = direct.NetworkInspect(ctx, net.ID, mobyclient.NetworkInspectOptions{})
+	assert.True(t, cerrdefs.IsNotFound(err))
+	_, err = direct.VolumeInspect(ctx, job, mobyclient.VolumeInspectOptions{})
+	assert.True(t, cerrdefs.IsNotFound(err))
+}
+
+func BenchmarkDockerProxy(b *testing.B) {
+	ctx := context.Background()
+	direct, err := GetDockerClient(ctx)
+	require.NoError(b, err)
+	defer direct.Close()
+	if _, err := direct.Ping(ctx, mobyclient.PingOptions{}); err != nil {
+		b.Skipf("docker daemon unreachable: %v", err)
+	}
+	proxy, err := StartDockerProxy(daemonSocketPath(b, direct), shortTempDir(b), "bench")
+	require.NoError(b, err)
+	defer func() { _ = proxy.Close(ctx) }()
+	viaProxy, err := mobyclient.New(mobyclient.WithHost("unix://" + proxy.Socket))
+	require.NoError(b, err)
+	defer viaProxy.Close()
+
+	require.NoError(b, NewDockerPullExecutor(NewDockerPullExecutorInput{Image: "alpine"})(ctx))
+	created, err := direct.ContainerCreate(ctx, mobyclient.ContainerCreateOptions{Config: &container.Config{Image: "alpine", Cmd: []string{"sleep", "600"}}})
+	require.NoError(b, err)
+	defer func() { _, _ = direct.ContainerRemove(ctx, created.ID, mobyclient.ContainerRemoveOptions{Force: true}) }()
+	_, err = direct.ContainerStart(ctx, created.ID, mobyclient.ContainerStartOptions{})
+	require.NoError(b, err)
+
+	var archive bytes.Buffer
+	writer := tar.NewWriter(&archive)
+	payload := make([]byte, 64<<20)
+	require.NoError(b, writer.WriteHeader(&tar.Header{Name: "blob", Mode: 0o600, Size: int64(len(payload))}))
+	_, _ = writer.Write(payload)
+	require.NoError(b, writer.Close())
+
+	for name, cli := range map[string]mobyclient.APIClient{"direct": direct, "proxy": viaProxy} {
+		b.Run("ping/"+name, func(b *testing.B) {
+			for b.Loop() {
+				if _, err := cli.Ping(ctx, mobyclient.PingOptions{}); err != nil {
+					b.Fatal(err)
+				}
+			}
+		})
+		b.Run("copy64MiB/"+name, func(b *testing.B) {
+			b.SetBytes(int64(archive.Len()))
+			for b.Loop() {
+				_, err := cli.CopyToContainer(ctx, created.ID, mobyclient.CopyToContainerOptions{DestinationPath: "/tmp", Content: bytes.NewReader(archive.Bytes())})
+				if err != nil {
+					b.Fatal(err)
+				}
+			}
+		})
+	}
+}

act/container/docker_run.go

@@ -138,12 +138,12 @@ func (cr *containerReference) Copy(destPath string, files ...*FileEntry) common.
 	).IfNot(common.Dryrun)
 }
 
-func (cr *containerReference) CopyDir(destPath, srcPath string, useGitIgnore bool) common.Executor {
+func (cr *containerReference) CopyDir(destPath, srcPath string, useGitIgnore, skipGitDir bool) common.Executor {
 	return common.NewPipelineExecutor(
 		common.NewInfoExecutor("docker cp src=%s dst=%s", srcPath, destPath),
 		cr.connect(),
 		cr.find(),
-		cr.copyDir(destPath, srcPath, useGitIgnore),
+		cr.copyDir(destPath, srcPath, useGitIgnore, skipGitDir),
 		func(ctx context.Context) error {
 			// If this fails, then folders have wrong permissions on non root container
 			if cr.UID != 0 || cr.GID != 0 {
@@ -252,6 +252,10 @@ func containerInfoFromInspect(inspect container.InspectResponse) *Info {
 		ID:     inspect.ID,
 		Health: HealthNone,
 		Ports:  map[string]string{}, // an empty map, never null, in the expression context
+		Mounts: make(map[string]string, len(inspect.Mounts)),
+	}
+	for _, mountPoint := range inspect.Mounts {
+		info.Mounts[mountPoint.Destination] = mountPoint.Source
 	}
 
 	if state := inspect.State; state != nil {
@@ -940,7 +944,7 @@ func (cr *containerReference) waitForCommand(ctx context.Context, resp client.Hi
 	}
 }
 
-func (cr *containerReference) copyDir(dstPath, srcPath string, useGitIgnore bool) common.Executor {
+func (cr *containerReference) copyDir(dstPath, srcPath string, useGitIgnore, skipGitDir bool) common.Executor {
 	return func(ctx context.Context) error {
 		if cr.id == "" {
 			return cr.missingContainerError("copy directory to %s", dstPath)
@@ -981,9 +985,10 @@ func (cr *containerReference) copyDir(dstPath, srcPath string, useGitIgnore bool
 		}
 
 		fc := &filecollector.FileCollector{
-			Ignorer:   ignorer,
-			SrcPath:   srcPath,
-			SrcPrefix: srcPrefix,
+			Ignorer:    ignorer,
+			SrcPath:    srcPath,
+			SrcPrefix:  srcPrefix,
+			SkipGitDir: skipGitDir,
 			Handler: &filecollector.TarCollector{
 				TarWriter: tw,
 				UID:       cr.UID,

act/container/docker_run_test.go

@@ -471,7 +471,7 @@ func TestRejectsMissingContainer(t *testing.T) {
 		assert.Contains(t, err.Error(), `container "job-1" does not exist`, op)
 	}
 	check("copyContent", cr.copyContent("/var/run/act", &FileEntry{Name: "x", Mode: 0o644})(ctx))
-	check("copyDir", cr.copyDir("/var/run/act", "/src", false)(ctx))
+	check("copyDir", cr.copyDir("/var/run/act", "/src", false, false)(ctx))
 	check("exec", cr.exec([]string{"echo"}, nil, "", "")(ctx))
 	_, err := cr.GetContainerArchive(ctx, "/var/run/act/x")
 	check("GetContainerArchive", err)
@@ -801,6 +801,20 @@ func TestContainerInfoFromInspect(t *testing.T) {
 		assert.Equal(t, "abc123", info.ID)
 		assert.Equal(t, HealthNone, info.Health)
 	})
+
+	t.Run("reports the mount sources by container path", func(t *testing.T) {
+		info := containerInfoFromInspect(container.InspectResponse{
+			Mounts: []container.MountPoint{
+				{Type: mount.TypeVolume, Name: "job", Source: "/var/lib/docker/volumes/job/_data", Destination: "/workspace/owner/repo"},
+				{Type: mount.TypeBind, Source: "/var/run/docker.sock", Destination: "/var/run/docker.sock"},
+			},
+		})
+
+		assert.Equal(t, map[string]string{
+			"/workspace/owner/repo": "/var/lib/docker/volumes/job/_data",
+			"/var/run/docker.sock":  "/var/run/docker.sock",
+		}, info.Mounts)
+	})
 }
 
 func TestMergeContainerConfigsVolumesReplaceRunnerMounts(t *testing.T) {

act/container/docker_stub.go

@@ -29,6 +29,14 @@ func RemoveImage(ctx context.Context, imageName string, force, pruneChildren boo
 	return false, errors.New("Unsupported Operation")
 }
 
+func DockerProxyDir(ctx context.Context) string {
+	return ""
+}
+
+func StartDockerProxy(daemonSocket, dir, job string) (*DockerProxy, error) {
+	return nil, errors.New("Unsupported Operation")
+}
+
 // NewDockerBuildExecutor function to create a run executor for the container
 func NewDockerBuildExecutor(input NewDockerBuildExecutorInput) common.Executor {
 	return func(ctx context.Context) error {

act/container/host_environment.go

@@ -92,7 +92,7 @@ func (e *HostEnvironment) Copy(destPath string, files ...*FileEntry) common.Exec
 	}
 }
 
-func (e *HostEnvironment) CopyDir(destPath, srcPath string, useGitIgnore bool) common.Executor {
+func (e *HostEnvironment) CopyDir(destPath, srcPath string, useGitIgnore, skipGitDir bool) common.Executor {
 	return func(ctx context.Context) error {
 		logger := common.Logger(ctx)
 		srcPrefix := filepath.Dir(srcPath)
@@ -110,9 +110,10 @@ func (e *HostEnvironment) CopyDir(destPath, srcPath string, useGitIgnore bool) c
 			ignorer = gitignore.NewMatcher(ps)
 		}
 		fc := &filecollector.FileCollector{
-			Ignorer:   ignorer,
-			SrcPath:   srcPath,
-			SrcPrefix: srcPrefix,
+			Ignorer:    ignorer,
+			SrcPath:    srcPath,
+			SrcPrefix:  srcPrefix,
+			SkipGitDir: skipGitDir,
 			Handler: &filecollector.CopyCollector{
 				DstDir: destPath,
 			},

act/container/host_environment_test.go

@@ -47,10 +47,32 @@ func TestCopyDir(t *testing.T) {
 	_ = os.MkdirAll(e.TmpDir, 0o700)
 	_ = os.MkdirAll(e.ToolCache, 0o700)
 	_ = os.MkdirAll(e.ActPath, 0o700)
-	err := e.CopyDir(e.Workdir, e.Path, true)(ctx)
+	err := e.CopyDir(e.Workdir, e.Path, true, false)(ctx)
 	assert.NoError(t, err)
 }
 
+func TestCopyDirSkipGitDir(t *testing.T) {
+	for name, skipGitDir := range map[string]bool{"kept for a workspace copy": false, "skipped for an action copy": true} {
+		t.Run(name, func(t *testing.T) {
+			src := filepath.Join(t.TempDir(), "action")
+			require.NoError(t, os.MkdirAll(filepath.Join(src, ".git", "objects"), 0o700))
+			require.NoError(t, os.WriteFile(filepath.Join(src, ".git", "objects", "pack"), []byte("x"), 0o600))
+			require.NoError(t, os.WriteFile(filepath.Join(src, "action.yml"), []byte("name: x\n"), 0o600))
+
+			dest := filepath.Join(t.TempDir(), "dest")
+			e := &HostEnvironment{StdOut: os.Stdout}
+			require.NoError(t, e.CopyDir(dest, src+string(filepath.Separator), false, skipGitDir)(context.Background()))
+
+			assert.FileExists(t, filepath.Join(dest, "action.yml"))
+			if skipGitDir {
+				assert.NoDirExists(t, filepath.Join(dest, ".git"))
+			} else {
+				assert.FileExists(t, filepath.Join(dest, ".git", "objects", "pack"))
+			}
+		})
+	}
+}
+
 func TestGetContainerArchive(t *testing.T) {
 	dir := t.TempDir()
 	ctx := context.Background()

act/filecollector/file_collector.go

@@ -94,10 +94,11 @@ func (cc *CopyCollector) WriteFile(fpath string, fi fs.FileInfo, linkName string
 }
 
 type FileCollector struct {
-	Ignorer   gitignore.Matcher
-	SrcPath   string
-	SrcPrefix string
-	Handler   Handler
+	Ignorer    gitignore.Matcher
+	SrcPath    string
+	SrcPrefix  string
+	SkipGitDir bool
+	Handler    Handler
 }
 
 func openGitIndex(path string) (*index.Index, error) {
@@ -124,6 +125,12 @@ func (fc *FileCollector) CollectFiles(ctx context.Context, submodulePath []strin
 		if fi.IsDir() && len(split) > 0 && split[len(split)-1] == "." {
 			return nil
 		}
+		if fc.SkipGitDir && split[len(split)-1] == ".git" {
+			if fi.IsDir() {
+				return filepath.SkipDir
+			}
+			return nil
+		}
 		var entry *index.Entry
 		if i != nil {
 			entry, err = i.Entry(strings.Join(split[len(submodulePath):], "/"))

act/runner/action.go

@@ -32,7 +32,7 @@ type actionStep interface {
 	step
 
 	getActionModel() *model.Action
-	getCompositeRunContext(context.Context) *RunContext
+	getCompositeRunContext(context.Context) (*RunContext, error)
 	getCompositeSteps() *compositeSteps
 }
 
@@ -154,7 +154,7 @@ func maybeCopyToActionDir(ctx context.Context, step actionStep, actionDir, actio
 		return err
 	}
 
-	return rc.JobContainer.CopyDir(containerActionDirCopy, actionDir+"/", rc.Config.UseGitIgnore)(ctx)
+	return rc.JobContainer.CopyDir(containerActionDirCopy, actionDir+"/", rc.Config.UseGitIgnore, true)(ctx)
 }
 
 func runActionImpl(step actionStep, actionDir string, remoteAction *remoteAction) common.Executor {
@@ -172,7 +172,9 @@ func runActionImpl(step actionStep, actionDir string, remoteAction *remoteAction
 
 		rc.withGithubEnv(ctx, step.getGithubContext(ctx), *step.getEnv())
 		populateEnvsFromSavedState(step.getEnv(), step, rc)
-		populateEnvsFromInput(ctx, step.getEnv(), action, rc)
+		if err := populateEnvsFromInput(ctx, step.getEnv(), action, rc); err != nil {
+			return err
+		}
 
 		actionLocation := path.Join(actionDir, actionPath)
 		actionName, containerActionDir := getContainerActionPaths(stepModel, actionLocation, rc)
@@ -352,23 +354,35 @@ func execAsDocker(ctx context.Context, step actionStep, actionName, actionDir, b
 		}
 	}
 	eval := rc.NewActionInputsExpressionEvaluator(ctx, step)
-	cmd, err := shellquote.Split(eval.Interpolate(ctx, step.getStepModel().With["args"]))
+	args, err := eval.Interpolate(ctx, step.getStepModel().With["args"])
+	if err != nil {
+		return fmt.Errorf("unable to interpolate with.args: %w", err)
+	}
+	cmd, err := shellquote.Split(args)
+	if err != nil {
+		return err
+	}
+	ee, err := evalDockerEnv(ctx, step, action)
 	if err != nil {
 		return err
 	}
-	ee := evalDockerEnv(ctx, step, action)
 	if action.Runs.Args != nil {
 		// a fresh slice, the manifest is evaluated again for every stage
 		cmd = make([]string, len(action.Runs.Args))
 		for i, v := range action.Runs.Args {
-			cmd[i] = ee.Interpolate(ctx, v)
+			if cmd[i], err = ee.Interpolate(ctx, v); err != nil {
+				return fmt.Errorf("unable to interpolate runs.args: %w", err)
+			}
 		}
 	}
 	entrypoint, err := dockerEntrypoint(ctx, step, eval, stage)
 	if err != nil {
 		return err
 	}
-	stepContainer := newStepContainer(ctx, step, image, cmd, entrypoint, rc.Config.ContainerOptions)
+	stepContainer, err := newStepContainer(ctx, step, image, cmd, entrypoint, rc.Config.ContainerOptions)
+	if err != nil {
+		return err
+	}
 	return common.NewPipelineExecutor(
 		prepImage,
 		stepContainer.Pull(forcePull),
@@ -392,7 +406,11 @@ func dockerEntrypoint(ctx context.Context, step actionStep, eval *expressionEval
 	default:
 		entrypoint = runs.Entrypoint
 		if entrypoint == "" {
-			if fields := strings.Fields(eval.Interpolate(ctx, step.getStepModel().With["entrypoint"])); len(fields) > 0 {
+			withEntrypoint, err := eval.Interpolate(ctx, step.getStepModel().With["entrypoint"])
+			if err != nil {
+				return nil, fmt.Errorf("unable to interpolate with.entrypoint: %w", err)
+			}
+			if fields := strings.Fields(withEntrypoint); len(fields) > 0 {
 				return fields, nil
 			}
 		}
@@ -405,19 +423,22 @@ func dockerEntrypoint(ctx context.Context, step actionStep, eval *expressionEval
 }
 
 // evalDockerEnv returns an evaluator bound to the environment it installed.
-func evalDockerEnv(ctx context.Context, step step, action *model.Action) *expressionEvaluator {
+func evalDockerEnv(ctx context.Context, step step, action *model.Action) (*expressionEvaluator, error) {
 	rc := step.getRunContext()
 	stepModel := step.getStepModel()
 
+	var err error
 	inputs := make(map[string]string)
 	eval := rc.NewExpressionEvaluator(ctx)
 	// Set Defaults
 	for k, input := range action.Inputs {
-		inputs[k] = eval.Interpolate(ctx, input.Default)
+		if inputs[k], err = eval.Interpolate(ctx, input.Default); err != nil {
+			return nil, fmt.Errorf("unable to interpolate the default of input %s: %w", k, err)
+		}
 	}
-	if stepModel.With != nil {
-		for k, v := range stepModel.With {
-			inputs[k] = eval.Interpolate(ctx, v)
+	for k, v := range stepModel.With {
+		if inputs[k], err = eval.Interpolate(ctx, v); err != nil {
+			return nil, fmt.Errorf("unable to interpolate with.%s: %w", k, err)
 		}
 	}
 	mergeIntoMap(step, step.getEnv(), inputs)
@@ -428,12 +449,14 @@ func evalDockerEnv(ctx context.Context, step step, action *model.Action) *expres
 
 	ee := rc.NewActionInputsExpressionEvaluator(ctx, step)
 	for k, v := range *step.getEnv() {
-		(*step.getEnv())[k] = ee.Interpolate(ctx, v)
+		if (*step.getEnv())[k], err = ee.Interpolate(ctx, v); err != nil {
+			return nil, fmt.Errorf("unable to interpolate env %s: %w", k, err)
+		}
 	}
-	return ee
+	return ee, nil
 }
 
-func newStepContainer(ctx context.Context, step step, image string, cmd, entrypoint []string, runnerOptions string) container.Container {
+func newStepContainer(ctx context.Context, step step, image string, cmd, entrypoint []string, runnerOptions string) (container.Container, error) {
 	rc := step.getRunContext()
 	logWriter := rc.commandLogWriter(ctx)
 	envList := make([]string, 0)
@@ -443,9 +466,12 @@ func newStepContainer(ctx context.Context, step step, image string, cmd, entrypo
 
 	envList = append(envList, rc.runnerEnv(ctx)...)
 
-	binds, mounts := rc.GetBindsAndMounts()
+	binds, mounts, err := rc.GetBindsAndMounts()
+	if err != nil {
+		return nil, err
+	}
 	networkMode := "container:" + rc.jobContainerName()
-	if rc.IsHostEnv(ctx) {
+	if rc.IsHostEnv() {
 		networkMode = "default"
 	}
 	return ContainerNewContainer(&container.NewContainerInput{
@@ -467,7 +493,7 @@ func newStepContainer(ctx context.Context, step step, image string, cmd, entrypo
 		AutoRemove:    true,
 		ValidVolumes:  rc.validVolumes(),
 		AllocatePTY:   rc.Config.AllocatePTY,
-	})
+	}), nil
 }
 
 func populateEnvsFromSavedState(env *map[string]string, step actionStep, rc *RunContext) {
@@ -480,15 +506,19 @@ func populateEnvsFromSavedState(env *map[string]string, step actionStep, rc *Run
 	}
 }
 
-func populateEnvsFromInput(ctx context.Context, env *map[string]string, action *model.Action, rc *RunContext) {
+func populateEnvsFromInput(ctx context.Context, env *map[string]string, action *model.Action, rc *RunContext) error {
 	eval := rc.NewExpressionEvaluator(ctx)
 	for inputID, input := range action.Inputs {
 		envKey := regexp.MustCompile("[^A-Z0-9-]").ReplaceAllString(strings.ToUpper(inputID), "_")
 		envKey = "INPUT_" + envKey
 		if _, ok := (*env)[envKey]; !ok {
-			(*env)[envKey] = eval.Interpolate(ctx, input.Default)
+			var err error
+			if (*env)[envKey], err = eval.Interpolate(ctx, input.Default); err != nil {
+				return fmt.Errorf("unable to interpolate the default of input %s: %w", inputID, err)
+			}
 		}
 	}
+	return nil
 }
 
 func getContainerActionPaths(step *model.Step, actionDir string, rc *RunContext) (string, string) {
@@ -588,11 +618,14 @@ func runPreStep(step actionStep) common.Executor {
 		actionDir, actionPath, _, containerActionDir := actionStagePaths(step)
 
 		x := action.Runs.Using
+		if !x.IsComposite() {
+			// defaults in pre steps were missing, however provided inputs are available
+			if err := populateEnvsFromInput(ctx, step.getEnv(), action, rc); err != nil {
+				return err
+			}
+		}
 		switch {
 		case x.IsNode():
-			// defaults in pre steps were missing, however provided inputs are available
-			populateEnvsFromInput(ctx, step.getEnv(), action, rc)
-
 			if err := maybeCopyToActionDir(ctx, step, actionDir, actionPath, containerActionDir); err != nil {
 				return err
 			}
@@ -605,14 +638,13 @@ func runPreStep(step actionStep) common.Executor {
 			return rc.JobContainer.Exec(containerArgs, *step.getEnv(), "", "")(ctx)
 
 		case x.IsDocker():
-			// defaults in pre steps were missing, however provided inputs are available
-			populateEnvsFromInput(ctx, step.getEnv(), action, rc)
-
 			return execDockerActionStage(ctx, step, stepStagePre)
 
 		case x.IsComposite():
 			if step.getCompositeSteps() == nil {
-				step.getCompositeRunContext(ctx)
+				if _, err := step.getCompositeRunContext(ctx); err != nil {
+					return err
+				}
 			}
 
 			if steps := step.getCompositeSteps(); steps != nil && steps.pre != nil {
@@ -621,9 +653,6 @@ func runPreStep(step actionStep) common.Executor {
 			return errors.New("missing steps in composite action")
 
 		case x == model.ActionRunsUsingGo:
-			// defaults in pre steps were missing, however provided inputs are available
-			populateEnvsFromInput(ctx, step.getEnv(), action, rc)
-
 			if err := maybeCopyToActionDir(ctx, step, actionDir, actionPath, containerActionDir); err != nil {
 				return err
 			}

act/runner/action_composite.go

@@ -7,6 +7,7 @@ package runner
 import (
 	"context"
 	"errors"
+	"fmt"
 	"regexp"
 	"slices"
 	"strconv"
@@ -17,7 +18,7 @@ import (
 	"gitea.dev/actionslib/pkg/model"
 )
 
-func evaluateCompositeInputAndEnv(ctx context.Context, parent *RunContext, step actionStep) map[string]string {
+func evaluateCompositeInputAndEnv(ctx context.Context, parent *RunContext, step actionStep) (map[string]string, error) {
 	env := make(map[string]string)
 	stepEnv := *step.getEnv()
 	for k, v := range stepEnv {
@@ -47,14 +48,17 @@ func evaluateCompositeInputAndEnv(ctx context.Context, parent *RunContext, step
 			env[envKey] = value
 		} else {
 			// defaults could contain expressions
-			env[envKey] = ee.Interpolate(ctx, input.Default)
+			var err error
+			if env[envKey], err = ee.Interpolate(ctx, input.Default); err != nil {
+				return nil, fmt.Errorf("unable to interpolate the default of input %s: %w", inputID, err)
+			}
 		}
 	}
 	gh := step.getGithubContext(ctx)
 	env["GITHUB_ACTION_REPOSITORY"] = gh.ActionRepository
 	env["GITHUB_ACTION_REF"] = gh.ActionRef
 
-	return env
+	return env, nil
 }
 
 func (rc *RunContext) setCompositeActionEnv(env map[string]string) {
@@ -66,8 +70,11 @@ func (rc *RunContext) setCompositeActionEnv(env map[string]string) {
 	}
 }
 
-func newCompositeRunContext(ctx context.Context, parent *RunContext, step actionStep, actionPath string) *RunContext {
-	env := evaluateCompositeInputAndEnv(ctx, parent, step)
+func newCompositeRunContext(ctx context.Context, parent *RunContext, step actionStep, actionPath string) (*RunContext, error) {
+	env, err := evaluateCompositeInputAndEnv(ctx, parent, step)
+	if err != nil {
+		return nil, err
+	}
 
 	// run with the global config but without secrets
 	configCopy := *parent.Config
@@ -87,20 +94,21 @@ func newCompositeRunContext(ctx context.Context, parent *RunContext, step action
 				},
 			},
 		},
-		Config:       &configCopy,
-		StepResults:  map[string]*model.StepResult{},
-		JobContainer: parent.JobContainer,
-		ActionPath:   actionPath,
-		GlobalEnv:    parent.GlobalEnv,
-		Masks:        parent.Masks,
-		ExtraPath:    parent.ExtraPath,
-		Parent:       parent,
-		EventJSON:    parent.EventJSON,
+		Config:        &configCopy,
+		StepResults:   map[string]*model.StepResult{},
+		JobContainer:  parent.JobContainer,
+		ActionPath:    actionPath,
+		GlobalEnv:     parent.GlobalEnv,
+		Masks:         parent.Masks,
+		ExtraPath:     parent.ExtraPath,
+		Parent:        parent,
+		EventJSON:     parent.EventJSON,
+		platformImage: parent.platformImage,
 	}
 	compositerc.setCompositeActionEnv(env)
 	compositerc.ExprEval = compositerc.NewExpressionEvaluator(ctx)
 
-	return compositerc
+	return compositerc, nil
 }
 
 // appendUniqueMasks appends the masks from src to dst, skipping any mask that
@@ -121,7 +129,10 @@ func execAsComposite(step actionStep) common.Executor {
 	action := step.getActionModel()
 
 	return func(ctx context.Context) error {
-		compositeRC := step.getCompositeRunContext(ctx)
+		compositeRC, err := step.getCompositeRunContext(ctx)
+		if err != nil {
+			return err
+		}
 
 		steps := step.getCompositeSteps()
 
@@ -131,14 +142,17 @@ func execAsComposite(step actionStep) common.Executor {
 
 		ctx = WithCompositeLogger(ctx, &compositeRC.Masks)
 
-		err := steps.main(ctx)
+		err = steps.main(ctx)
 
 		// Map outputs from composite RunContext to job RunContext
 		eval := compositeRC.NewExpressionEvaluator(ctx)
 		for outputName, output := range action.Outputs {
-			rc.setOutput(ctx, map[string]string{
-				"name": outputName,
-			}, eval.Interpolate(ctx, output.Value))
+			value, outputErr := eval.Interpolate(ctx, output.Value)
+			if outputErr != nil {
+				err = errors.Join(err, fmt.Errorf("unable to interpolate output %s: %w", outputName, outputErr))
+				continue
+			}
+			rc.setOutput(ctx, map[string]string{"name": outputName}, value)
 		}
 
 		// compositeRC.Masks is seeded with rc.Masks (see newCompositeRunContext)

act/runner/action_composite_test.go

@@ -19,25 +19,30 @@ func TestCompositeActionParity(t *testing.T) {
 		ctx := t.Context()
 		strategy := &model.Strategy{MaxParallel: 3}
 		parent := &RunContext{
-			Config:       &Config{},
-			Matrix:       map[string]any{"os": "linux"},
-			Run:          &model.Run{JobID: "job", Workflow: &model.Workflow{Name: "workflow", Jobs: map[string]*model.Job{"job": {Strategy: strategy}}}},
-			JobContainer: &jobContainerMock{},
+			Config:        &Config{},
+			Matrix:        map[string]any{"os": "linux"},
+			Run:           &model.Run{JobID: "job", Workflow: &model.Workflow{Name: "workflow", Jobs: map[string]*model.Job{"job": {Strategy: strategy}}}},
+			JobContainer:  &jobContainerMock{},
+			platformImage: "-self-hosted",
 		}
-		composite := newCompositeRunContext(ctx, parent, &stepActionRemote{
+		composite, err := newCompositeRunContext(ctx, parent, &stepActionRemote{
 			Step:       &model.Step{With: map[string]string{"SHARED": "outer"}},
 			RunContext: parent,
 			action:     &model.Action{Inputs: map[string]model.Input{"shared": {Default: "outer-default"}}},
 			env:        map[string]string{"INPUT_SHARED": "outer"},
 		}, "/action")
+		require.NoError(t, err)
 
 		assert.Same(t, strategy, composite.Run.Job().Strategy)
-		assert.Equal(t, "linux|3|outer", composite.NewExpressionEvaluator(ctx).Interpolate(ctx,
-			"${{ matrix.os }}|${{ strategy.max-parallel }}|${{ inputs.shared }}"))
+		assert.True(t, composite.IsHostEnv())
+		interpolated, err := composite.NewExpressionEvaluator(ctx).Interpolate(ctx,
+			"${{ matrix.os }}|${{ strategy.max-parallel }}|${{ inputs.shared }}")
+		require.NoError(t, err)
+		assert.Equal(t, "linux|3|outer", interpolated)
 		assert.NotContains(t, composite.Env, "INPUT_SHARED")
 
 		nestedEnv := composite.GetEnv()
-		populateEnvsFromInput(ctx, &nestedEnv, &model.Action{Inputs: map[string]model.Input{"shared": {Default: "inner-default"}}}, composite)
+		require.NoError(t, populateEnvsFromInput(ctx, &nestedEnv, &model.Action{Inputs: map[string]model.Input{"shared": {Default: "inner-default"}}}, composite))
 		assert.Equal(t, "inner-default", nestedEnv["INPUT_SHARED"])
 	})
 

act/runner/action_test.go

@@ -227,7 +227,7 @@ func TestActionRunner(t *testing.T) {
 			ctx := context.Background()
 
 			cm := &containerMock{}
-			cm.On("CopyDir", "/var/run/act/actions/dir/", "dir/", false).Return(func(ctx context.Context) error { return nil })
+			cm.On("CopyDir", "/var/run/act/actions/dir/", "dir/", false, true).Return(func(ctx context.Context) error { return nil })
 
 			envMatcher := mock.MatchedBy(func(env map[string]string) bool {
 				for k, v := range tt.expectedEnv {
@@ -316,7 +316,7 @@ func TestNewStepContainerDoesNotUseDockerSecrets(t *testing.T) {
 	step.On("getStepModel").Return(&model.Step{ID: "action"})
 	step.On("getEnv").Return(&env)
 
-	_ = newStepContainer(ctx, step, "registry.example.com/action:tag", nil, nil, "")
+	_, _ = newStepContainer(ctx, step, "registry.example.com/action:tag", nil, nil, "")
 
 	// DOCKER_USERNAME/DOCKER_PASSWORD should not be injected as pull credentials for docker action containers.
 	assert.Empty(t, captured.Username)
@@ -337,7 +337,7 @@ func TestMaybeCopyToActionDirHoldsCloneLock(t *testing.T) {
 	copyEntered := make(chan struct{})
 
 	cm := &containerMock{}
-	cm.On("CopyDir", "/var/run/act/actions/", actionDir+"/", false).Return(func(ctx context.Context) error {
+	cm.On("CopyDir", "/var/run/act/actions/", actionDir+"/", false, true).Return(func(ctx context.Context) error {
 		close(copyEntered)
 		<-releaseCopy
 		return nil

act/runner/container_mock_test.go

@@ -57,8 +57,8 @@ func (cm *containerMock) Copy(destPath string, files ...*container.FileEntry) co
 	return args.Get(0).(func(context.Context) error)
 }
 
-func (cm *containerMock) CopyDir(destPath, srcPath string, useGitIgnore bool) common.Executor {
-	args := cm.Called(destPath, srcPath, useGitIgnore)
+func (cm *containerMock) CopyDir(destPath, srcPath string, useGitIgnore, skipGitDir bool) common.Executor {
+	args := cm.Called(destPath, srcPath, useGitIgnore, skipGitDir)
 	return args.Get(0).(func(context.Context) error)
 }
 

act/runner/expression.go

@@ -13,6 +13,7 @@ import (
 	"reflect"
 	"regexp"
 	"strings"
+	"sync"
 	"time"
 
 	"gitea.com/gitea/runner/act/common"
@@ -71,7 +72,7 @@ func (rc *RunContext) NewExpressionEvaluatorWithEnv(ctx context.Context, env map
 	}
 
 	ghc := rc.getGithubContext(ctx)
-	inputs := getEvaluatorInputs(ctx, rc, rc.actionInputs, ghc)
+	inputs := getEvaluatorInputs(rc, rc.actionInputs, ghc)
 
 	ee := &exprparser.EvaluationEnvironment{
 		Github: ghc,
@@ -81,7 +82,7 @@ func (rc *RunContext) NewExpressionEvaluatorWithEnv(ctx context.Context, env map
 		// todo: should be unavailable
 		// but required to interpolate/evaluate the step outputs on the job
 		Steps:     rc.getStepsContext(),
-		Secrets:   getWorkflowSecrets(ctx, rc),
+		Secrets:   getWorkflowSecrets(rc),
 		Vars:      getWorkflowVars(ctx, rc),
 		Strategy:  strategy,
 		Matrix:    rc.Matrix,
@@ -137,14 +138,14 @@ func (rc *RunContext) newStepExpressionEvaluator(ctx context.Context, step step,
 		Env:      *step.getEnv(),
 		Job:      rc.getJobContext(),
 		Steps:    rc.getStepsContext(),
-		Secrets:  getWorkflowSecrets(ctx, rc),
+		Secrets:  getWorkflowSecrets(rc),
 		Vars:     getWorkflowVars(ctx, rc),
 		Strategy: strategy,
 		Matrix:   rc.Matrix,
 		Needs:    using,
 		// todo: should be unavailable
 		// but required to interpolate/evaluate the inputs in actions/composite
-		Inputs:    getEvaluatorInputs(ctx, rc, stepInputs, rc.getGithubContext(ctx)),
+		Inputs:    getEvaluatorInputs(rc, stepInputs, rc.getGithubContext(ctx)),
 		HashFiles: getHashFilesFunction(ctx, rc),
 	}
 	ee.Runner = rc.getRunnerContext(ctx)
@@ -246,17 +247,18 @@ func (ee expressionEvaluator) EvaluateYamlNode(ctx context.Context, node *yaml.N
 	return ee.shared(ctx).EvaluateYamlNode(node)
 }
 
-func (ee expressionEvaluator) Interpolate(ctx context.Context, in string) string {
-	out, err := ee.interpolate(ctx, in)
-	if err != nil {
-		common.Logger(ctx).Errorf("Unable to interpolate expression '%s': %s", in, err)
-		return ""
-	}
-	return out
+func (ee expressionEvaluator) Interpolate(ctx context.Context, in string) (string, error) {
+	return ee.shared(ctx).Interpolate(in)
 }
 
-func (ee expressionEvaluator) interpolate(ctx context.Context, in string) (string, error) {
-	return ee.shared(ctx).Interpolate(in)
+// InterpolateName keeps the source text of a job or step name that cannot be evaluated, as GitHub does.
+func (ee expressionEvaluator) InterpolateName(ctx context.Context, in string) string {
+	out, err := ee.Interpolate(ctx, in)
+	if err != nil {
+		common.Logger(ctx).Warnf("Unable to evaluate the display name '%s': %s", in, err)
+		return in
+	}
+	return out
 }
 
 // EvalBool evaluates an expression against given evaluator. An `if:` is an expression even without
@@ -277,10 +279,10 @@ func inputsFromEnv(env map[string]string) map[string]any {
 	return inputs
 }
 
-func getEvaluatorInputs(ctx context.Context, rc *RunContext, stepInputs map[string]any, ghc *model.GithubContext) map[string]any {
+func getEvaluatorInputs(rc *RunContext, stepInputs map[string]any, ghc *model.GithubContext) map[string]any {
 	inputs := map[string]any{}
 
-	setupWorkflowInputs(ctx, &inputs, rc)
+	maps.Copy(inputs, rc.workflowCallInputs)
 	maps.Copy(inputs, stepInputs)
 
 	if ghc.EventName == "workflow_dispatch" {
@@ -324,54 +326,49 @@ func coerceInputValue(value any, inputType string) any {
 	return value == "true"
 }
 
-func setupWorkflowInputs(ctx context.Context, inputs *map[string]any, rc *RunContext) {
-	if rc.caller != nil {
-		config := rc.Run.Workflow.WorkflowCallConfig()
+// resolveWorkflowCall evaluates the caller's with: and secrets: once, as the server does before dispatching a called workflow.
+func (rc *RunContext) resolveWorkflowCall(ctx context.Context) error {
+	if rc.caller == nil {
+		return nil
+	}
+	callerJob := rc.caller.runContext.Run.Job()
+	callerEval := rc.caller.runContext.ExprEval
+	calleeEval := sync.OnceValue(func() *expressionEvaluator { return rc.NewExpressionEvaluator(ctx) })
+	config := rc.Run.Workflow.WorkflowCallConfig()
 
-		for name, input := range config.Inputs {
-			value := rc.caller.runContext.Run.Job().With[name]
-			if value != nil {
-				if str, ok := value.(string); ok {
-					// evaluate using the calling RunContext (outside)
-					value = rc.caller.runContext.ExprEval.Interpolate(ctx, str)
-				}
+	rc.workflowCallInputs = make(map[string]any, len(config.Inputs))
+	for name, input := range config.Inputs {
+		value, eval, label := callerJob.With[name], callerEval, "input"
+		if value == nil {
+			value, eval, label = input.Default, calleeEval(), "the default of input"
+		}
+		if str, ok := value.(string); ok {
+			var err error
+			if value, err = eval.Interpolate(ctx, str); err != nil {
+				return fmt.Errorf("unable to interpolate %s %s: %w", label, name, err)
 			}
+		}
+		rc.workflowCallInputs[name] = coerceInputValue(value, input.Type)
+	}
 
-			if value == nil && config != nil && config.Inputs != nil {
-				value = input.Default
-				if rc.ExprEval != nil {
-					if str, ok := value.(string); ok {
-						// evaluate using the called RunContext (inside)
-						value = rc.ExprEval.Interpolate(ctx, str)
-					}
-				}
-			}
-
-			(*inputs)[name] = coerceInputValue(value, input.Type)
+	secrets := callerJob.Secrets()
+	if secrets == nil && callerJob.InheritSecrets() {
+		secrets = rc.caller.runContext.Config.Secrets
+	}
+	rc.workflowCallSecrets = make(map[string]string, len(secrets))
+	for k, v := range secrets {
+		var err error
+		if rc.workflowCallSecrets[k], err = callerEval.Interpolate(ctx, v); err != nil {
+			return fmt.Errorf("unable to interpolate secret %s: %w", k, err)
 		}
 	}
+	return nil
 }
 
-func getWorkflowSecrets(ctx context.Context, rc *RunContext) map[string]string {
+func getWorkflowSecrets(rc *RunContext) map[string]string {
 	if rc.caller != nil {
-		job := rc.caller.runContext.Run.Job()
-		secrets := job.Secrets()
-
-		if secrets == nil && job.InheritSecrets() {
-			secrets = rc.caller.runContext.Config.Secrets
-		}
-
-		// Interpolate into a new map. secrets may be the shared Config.Secrets (or the job's
-		// map), which other parallel jobs read concurrently (e.g. log masking), so mutating it
-		// in place is a data race.
-		interpolated := make(map[string]string, len(secrets))
-		for k, v := range secrets {
-			interpolated[k] = rc.caller.runContext.ExprEval.Interpolate(ctx, v)
-		}
-
-		return interpolated
+		return rc.workflowCallSecrets
 	}
-
 	return rc.Config.Secrets
 }
 

act/runner/expression_test.go

@@ -266,19 +266,21 @@ func TestInterpolate(t *testing.T) {
 		{"${{ null }}", ""},
 		{"${{ fromJSON('[1,2]') }}", "Array"},
 		{"${{ fromJSON('{\"a\":1}') }}", "Object"},
-		// a malformed part must not restructure its neighbours, and it interpolates to nothing
-		{"${{ 1) && (2 }}", ""},
-		{"run ${{ 1) && (2 }} now", ""},
 		{"${{ 1", "${{ 1"},
 	}
 
 	for _, table := range tables {
 		t.Run("interpolate", func(t *testing.T) {
-			assertObject := assert.New(t)
-			out := ee.Interpolate(context.Background(), table.in)
-			assertObject.Equal(table.out, out, table.in)
+			out, err := ee.Interpolate(context.Background(), table.in)
+			require.NoError(t, err, table.in)
+			assert.Equal(t, table.out, out, table.in)
 		})
 	}
+
+	for _, in := range []string{"${{ 1) && (2 }}", "run ${{ 1) && (2 }} now"} {
+		_, err := ee.Interpolate(context.Background(), in)
+		assert.Error(t, err, in)
+	}
 }
 
 func TestGetEvaluatorInputsBoolean(t *testing.T) {
@@ -352,7 +354,7 @@ on:
 				}
 				ghc := &model.GithubContext{EventName: eventName, Event: table.event}
 
-				inputs := getEvaluatorInputs(context.Background(), rc, nil, ghc)
+				inputs := getEvaluatorInputs(rc, nil, ghc)
 				assert.Equal(t, table.flag, inputs["flag"])
 				assert.Equal(t, "gitea", inputs["name"])
 			})
@@ -372,7 +374,8 @@ jobs:
 
 	runner := &runnerImpl{config: &Config{Secrets: map[string]string{"A": "s3cr3t-a", "B": "s3cr3t-b"}}}
 	containerName := func(jobID string) string {
-		rc := runner.newRunContext(t.Context(), &model.Run{JobID: jobID, Workflow: workflow}, nil)
+		rc, err := runner.newRunContext(t.Context(), &model.Run{JobID: jobID, Workflow: workflow}, nil)
+		require.NoError(t, err)
 		assert.NotContains(t, rc.Name, "s3cr3t")
 		return rc.jobContainerName()
 	}

act/runner/job_executor.go

@@ -18,6 +18,7 @@ import (
 	"slices"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 	"unicode"
 
@@ -154,11 +155,9 @@ func newJobExecutor(info jobInfo, sf stepFactory, rc *RunContext) common.Executo
 		if rc.Run == nil {
 			return nil
 		}
-		rc.ExprEval = rc.NewExpressionEvaluator(ctx)
-		// evaluate environment variables since they can contain
-		// GitHub's special environment variables.
-		for k, v := range rc.GetEnv() {
-			rc.Env[k] = rc.ExprEval.Interpolate(ctx, v)
+		if err := evaluateJobEnvAndDefaults(ctx, rc); err != nil {
+			reportStepError(ctx, rc, err)
+			return err
 		}
 		return nil
 	})
@@ -240,6 +239,8 @@ func newJobExecutor(info jobInfo, sf stepFactory, rc *RunContext) common.Executo
 		// swallowed: a bad output fails this job, it must not abandon the rest of the plan
 		if err := info.interpolateOutputs()(ctx); err != nil {
 			reportStepError(ctx, rc, err)
+		} else if err := setJobOutputs(ctx, rc); err != nil {
+			reportStepError(ctx, rc, err)
 		}
 		return nil
 	})
@@ -258,7 +259,6 @@ func newJobExecutor(info jobInfo, sf stepFactory, rc *RunContext) common.Executo
 			logger.Errorf("##[error]%s", EscapeCommandData("Error while stop job container: "+err.Error()))
 		}
 		setJobResult(ctx, info, rc, jobError == nil)
-		setJobOutputs(ctx, rc)
 
 		return err
 	})
@@ -413,30 +413,58 @@ func setJobResult(ctx context.Context, info jobInfo, rc *RunContext, success boo
 	logger.WithField("jobResult", jobResult).Infof("Job %s", jobResultMessage)
 }
 
-func setJobOutputs(ctx context.Context, rc *RunContext) {
-	if rc.caller != nil {
-		// map outputs for reusable workflows
-		callerOutputs := make(map[string]string)
-
-		ee := rc.NewExpressionEvaluator(ctx)
-
-		for k, v := range rc.Run.Workflow.WorkflowCallConfig().Outputs {
-			callerOutputs[k] = ee.Interpolate(ctx, ee.Interpolate(ctx, v.Value))
+// evaluateJobEnvAndDefaults resolves the job's env and defaults.run once, as GitHub does at job setup.
+func evaluateJobEnvAndDefaults(ctx context.Context, rc *RunContext) error {
+	rc.ExprEval = rc.NewExpressionEvaluator(ctx)
+	var err error
+	for k, v := range rc.GetEnv() {
+		if rc.Env[k], err = rc.ExprEval.Interpolate(ctx, v); err != nil {
+			return fmt.Errorf("unable to interpolate env %s: %w", k, err)
 		}
-
-		// Matrix combinations of a reusable-workflow caller share the caller's *model.Job;
-		// serialize the write so parallel combos don't race on its Outputs field.
-		callerJob := rc.caller.runContext.Run.Job()
-		defer lockJob(callerJob)()
-		callerJob.Outputs = callerOutputs
 	}
+	defaults := rc.Run.Job().Defaults.Run
+	if rc.jobRunDefaults.Shell, err = rc.ExprEval.Interpolate(ctx, defaults.Shell); err != nil {
+		return fmt.Errorf("unable to interpolate defaults.run.shell: %w", err)
+	}
+	if rc.jobRunDefaults.WorkingDirectory, err = rc.ExprEval.Interpolate(ctx, defaults.WorkingDirectory); err != nil {
+		return fmt.Errorf("unable to interpolate defaults.run.working-directory: %w", err)
+	}
+	return nil
+}
+
+func setJobOutputs(ctx context.Context, rc *RunContext) error {
+	if rc.caller == nil {
+		return nil
+	}
+	outputs := rc.Run.Workflow.WorkflowCallConfig().Outputs
+	callerOutputs := make(map[string]string, len(outputs))
+	ee := sync.OnceValue(func() *expressionEvaluator { return rc.NewExpressionEvaluator(ctx) })
+	for k, v := range outputs {
+		value := v.Value
+		for range 2 { // two passes, the value resolves through a job output
+			var err error
+			if value, err = ee().Interpolate(ctx, value); err != nil {
+				return fmt.Errorf("unable to interpolate workflow output %s: %w", k, err)
+			}
+		}
+		callerOutputs[k] = value
+	}
+
+	// Matrix combinations of a reusable-workflow caller share the caller's *model.Job;
+	// serialize the write so parallel combos don't race on its Outputs field.
+	callerJob := rc.caller.runContext.Run.Job()
+	defer lockJob(callerJob)()
+	callerJob.Outputs = callerOutputs
+	return nil
 }
 
 // applyJobTimeout applies the job-level timeout-minutes to ctx, mirroring the
 // step-level evaluateStepTimeout in step.go.
 func applyJobTimeout(ctx context.Context, rc *RunContext, job *model.Job) (context.Context, context.CancelFunc) {
-	timeout := rc.ExprEval.Interpolate(ctx, job.TimeoutMinutes)
-	if timeout != "" {
+	timeout, err := rc.ExprEval.Interpolate(ctx, job.TimeoutMinutes)
+	if err != nil {
+		common.Logger(ctx).Errorf("An error occurred when attempting to determine the job timeout: %s", err)
+	} else if timeout != "" {
 		if timeoutMinutes, err := strconv.ParseInt(timeout, 10, 64); err == nil {
 			return context.WithTimeout(ctx, time.Duration(timeoutMinutes)*time.Minute)
 		}
@@ -635,7 +663,7 @@ func archiveEntryMatchesPath(entryName, requestedPath string) bool {
 
 func useStepLogger(rc *RunContext, stepModel *model.Step, stage stepStage, executor common.Executor) common.Executor {
 	return func(ctx context.Context) error {
-		ctx = withStepLogger(ctx, stepModel.Number, stepModel.ID, rc.ExprEval.Interpolate(ctx, stepModel.String()), stage.String())
+		ctx = withStepLogger(ctx, stepModel.Number, stepModel.ID, rc.ExprEval.InterpolateName(ctx, stepModel.String()), stage.String())
 
 		logWriter := rc.commandLogWriter(ctx)
 

act/runner/patch_actions_test.go

@@ -244,7 +244,7 @@ func TestPatchActionsAtTheContainerCopy(t *testing.T) {
 		require.NoError(t, os.WriteFile(script, []byte(gateTSC), 0o600))
 
 		var copied string
-		cm.On("CopyDir", mock.Anything, mock.Anything, mock.Anything).Return(func(context.Context) error {
+		cm.On("CopyDir", mock.Anything, mock.Anything, mock.Anything, mock.Anything).Return(func(context.Context) error {
 			body, err := os.ReadFile(script)
 			require.NoError(t, err)
 			copied = string(body)

act/runner/reusable_workflow.go

@@ -95,9 +95,12 @@ func newRemoteReusableWorkflowExecutor(rc *RunContext) common.Executor {
 // remoteReusableWorkflow.URL = rc.getGithubContext(ctx).ServerURL
 func cloneRemoteReusableWorkflow(rc *RunContext, cloneURL, ref, targetDirectory, token string) common.Executor {
 	return func(ctx context.Context) error {
-		cloneURL = rc.NewExpressionEvaluator(ctx).Interpolate(ctx, cloneURL)
+		interpolatedURL, err := rc.NewExpressionEvaluator(ctx).Interpolate(ctx, cloneURL)
+		if err != nil {
+			return fmt.Errorf("unable to interpolate the workflow clone URL: %w", err)
+		}
 		return git.NewGitCloneExecutor(git.NewGitCloneExecutorInput{
-			URL:         cloneURL,
+			URL:         interpolatedURL,
 			Ref:         ref,
 			Dir:         targetDirectory,
 			Token:       token,

act/runner/run_context.go

@@ -67,7 +67,11 @@ type RunContext struct {
 	actionInputs        map[string]any // inputs of the composite action this runs, nil for a job
 	Masks               []string
 	cleanUpJobContainer common.Executor
-	caller              *caller // job calling this RunContext (reusable workflows)
+	caller              *caller           // job calling this RunContext (reusable workflows)
+	workflowCallInputs  map[string]any    // the caller's with:, resolved once by resolveWorkflowCall
+	workflowCallSecrets map[string]string // the caller's secrets:, resolved once by resolveWorkflowCall
+	jobRunDefaults      model.RunDefaults // defaults.run, resolved once at job setup as GitHub does
+	platformImage       string            // container.image or the runs-on pick, resolved once by isEnabled
 	// summaryFileInitialized tracks which per-step summary files (workflow/step-summary-N.md)
 	// have already been created on the JobContainer. The runner sets up file-command files
 	// via JobContainer.Copy at the start of every phase, which truncates them — fine for
@@ -92,6 +96,7 @@ type RunContext struct {
 	jobContainerID string
 	hasBash        *bool // memoized implicit-shell probe, only set on the top-level RunContext
 	jobNetworkName string
+	dockerProxy    *container.DockerProxy
 	// stepEnv is a copy of the running step's environment, so that workflow commands parsed out
 	// of the container's output can be judged against it. Written by runStepExecutor and read on
 	// the log-writer goroutine, hence unsecureCommandMu, which also guards unsecureCommandErr.
@@ -246,11 +251,41 @@ func (rc *RunContext) validVolumes() []string {
 	if rc.Config.SharedToolCache {
 		volumes = append(volumes, sharedToolCacheVolume)
 	}
+	if rc.Config.BindWorkdir {
+		volumes = append(volumes, rc.Config.Workdir)
+	}
+	if rc.dockerProxy != nil {
+		volumes = append(volumes, rc.dockerProxy.Socket)
+	}
 	// TODO: add a new configuration to control whether the docker daemon can be mounted
 	return append(volumes, name, name+"-env",
 		getDockerDaemonSocketMountPath(rc.containerDaemonSocket()))
 }
 
+func (rc *RunContext) jobDockerSocket() string {
+	if rc.dockerProxy != nil {
+		return rc.dockerProxy.Socket
+	}
+	return getDockerDaemonSocketMountPath(rc.containerDaemonSocket())
+}
+
+func (rc *RunContext) startDockerProxy(ctx context.Context) {
+	daemonSocket := rc.containerDaemonSocket()
+	if daemonSocket == "-" || strings.HasPrefix(strings.ToLower(daemonSocket), "npipe://") {
+		return
+	}
+	dir := container.DockerProxyDir(ctx)
+	if dir == "" {
+		return
+	}
+	proxy, err := container.StartDockerProxy(getDockerDaemonSocketMountPath(daemonSocket), dir, rc.jobContainerName())
+	if err != nil {
+		common.Logger(ctx).Warnf("docker proxy not started, the job gets the daemon socket directly: %v", err)
+		return
+	}
+	rc.dockerProxy = proxy
+}
+
 // toolCache returns the tool cache path the job sees, relocatable through RUNNER_TOOL_CACHE.
 func (rc *RunContext) toolCache(fallback string) string {
 	if path := rc.GetEnv()["RUNNER_TOOL_CACHE"]; path != "" {
@@ -299,7 +334,7 @@ func splitVolumes(specs []string) ([]string, map[string]string, map[string]bool)
 }
 
 // Returns the binds and mounts for the container, resolving paths as appopriate
-func (rc *RunContext) GetBindsAndMounts() ([]string, map[string]string) {
+func (rc *RunContext) GetBindsAndMounts() ([]string, map[string]string, error) {
 	name := rc.jobContainerName()
 	ext := container.LinuxContainerEnvironmentExtensions{}
 
@@ -308,7 +343,10 @@ func (rc *RunContext) GetBindsAndMounts() ([]string, map[string]string) {
 		if container := job.Container(); container != nil {
 			for _, v := range container.Volumes {
 				if rc.ExprEval != nil {
-					v = rc.ExprEval.Interpolate(context.Background(), v)
+					var err error
+					if v, err = rc.ExprEval.Interpolate(context.Background(), v); err != nil {
+						return nil, nil, fmt.Errorf("unable to interpolate container.volumes: %w", err)
+					}
 				}
 				volumes = append(volumes, v)
 			}
@@ -317,8 +355,8 @@ func (rc *RunContext) GetBindsAndMounts() ([]string, map[string]string) {
 	// the runner's own mounts below yield to the targets the job claims
 	binds, mounts, claimed := splitVolumes(volumes)
 
-	if daemonSocket := rc.containerDaemonSocket(); daemonSocket != "-" && !claimed["/var/run/docker.sock"] {
-		binds = append(binds, getDockerDaemonSocketMountPath(daemonSocket)+":/var/run/docker.sock")
+	if rc.containerDaemonSocket() != "-" && !claimed["/var/run/docker.sock"] {
+		binds = append(binds, rc.jobDockerSocket()+":/var/run/docker.sock")
 	}
 	if rc.Config.SharedToolCache {
 		if toolCache := rc.toolCache(container.DefaultToolCache); !claimed[toolCache] {
@@ -342,7 +380,7 @@ func (rc *RunContext) GetBindsAndMounts() ([]string, map[string]string) {
 		}
 	}
 
-	return binds, mounts
+	return binds, mounts, nil
 }
 
 func (rc *RunContext) startHostEnvironment() common.Executor {
@@ -433,7 +471,7 @@ var newContainer = container.NewContainer
 func (rc *RunContext) startJobContainer() common.Executor {
 	return func(ctx context.Context) error {
 		logger := common.Logger(ctx)
-		image := rc.platformImage(ctx)
+		image := rc.platformImage
 		logWriter := rc.commandLogWriter(ctx)
 
 		username, password, err := rc.handleCredentials(ctx)
@@ -445,6 +483,7 @@ func (rc *RunContext) startJobContainer() common.Executor {
 		// For gitea, to support --volumes-from <container_name_or_id> in options.
 		// We need to set the container name to the environment variable.
 		rc.Env["JOB_CONTAINER_NAME"] = name
+		rc.startDockerProxy(ctx)
 
 		envList := make([]string, 0)
 
@@ -452,7 +491,10 @@ func (rc *RunContext) startJobContainer() common.Executor {
 		envList = append(envList, fmt.Sprintf("%s=%s", "LANG", "C.UTF-8")) // Use same locale as GitHub Actions
 
 		ext := container.LinuxContainerEnvironmentExtensions{}
-		binds, mounts := rc.GetBindsAndMounts()
+		binds, mounts, err := rc.GetBindsAndMounts()
+		if err != nil {
+			return err
+		}
 
 		// specify the network to which the container will connect when `docker create` stage. (like execute command line: docker create --network <networkName> <image>)
 		// if using service containers, will create a new network for the containers.
@@ -463,7 +505,10 @@ func (rc *RunContext) startJobContainer() common.Executor {
 		for serviceID, spec := range rc.Run.Job().Services {
 			// GitHub compatibility: skip services whose image evaluates to an
 			// empty string, enabling conditional services via expressions
-			serviceImage := rc.ExprEval.Interpolate(ctx, spec.Image)
+			serviceImage, err := rc.ExprEval.Interpolate(ctx, spec.Image)
+			if err != nil {
+				return fmt.Errorf("unable to interpolate service %s image: %w", serviceID, err)
+			}
 			if serviceImage == "" {
 				logger.Infof("The service '%s' will not be started because the container definition has an empty image.", serviceID)
 				continue
@@ -473,16 +518,20 @@ func (rc *RunContext) startJobContainer() common.Executor {
 			// a service reaches the internet the way the job does; its own env still wins
 			maps0.Copy(interpolatedEnvs, rc.Config.ProxyEnv)
 			for k, v := range spec.Env {
-				interpolatedEnvs[k] = rc.ExprEval.Interpolate(ctx, v)
+				if interpolatedEnvs[k], err = rc.ExprEval.Interpolate(ctx, v); err != nil {
+					return fmt.Errorf("unable to interpolate service %s env %s: %w", serviceID, k, err)
+				}
 			}
 			envs := make([]string, 0, len(interpolatedEnvs))
 			for k, v := range interpolatedEnvs {
 				envs = append(envs, fmt.Sprintf("%s=%s", k, v))
 			}
 			// interpolate cmd
-			interpolatedCmd := make([]string, 0, len(spec.Cmd))
-			for _, v := range spec.Cmd {
-				interpolatedCmd = append(interpolatedCmd, rc.ExprEval.Interpolate(ctx, v))
+			interpolatedCmd := make([]string, len(spec.Cmd))
+			for i, v := range spec.Cmd {
+				if interpolatedCmd[i], err = rc.ExprEval.Interpolate(ctx, v); err != nil {
+					return fmt.Errorf("unable to interpolate service %s command: %w", serviceID, err)
+				}
 			}
 			// keep these local: reusing username/password would overwrite the
 			// credentials the job container is pulled with further down
@@ -491,20 +540,28 @@ func (rc *RunContext) startJobContainer() common.Executor {
 				return fmt.Errorf("failed to handle service %s credentials: %w", serviceID, err)
 			}
 
-			interpolatedVolumes := make([]string, 0, len(spec.Volumes))
-			for _, volume := range spec.Volumes {
-				interpolatedVolumes = append(interpolatedVolumes, rc.ExprEval.Interpolate(ctx, volume))
+			interpolatedVolumes := make([]string, len(spec.Volumes))
+			for i, volume := range spec.Volumes {
+				if interpolatedVolumes[i], err = rc.ExprEval.Interpolate(ctx, volume); err != nil {
+					return fmt.Errorf("unable to interpolate service %s volumes: %w", serviceID, err)
+				}
 			}
 			serviceBinds, serviceMounts, _ := splitVolumes(interpolatedVolumes)
 
-			interpolatedPorts := make([]string, 0, len(spec.Ports))
-			for _, port := range spec.Ports {
-				interpolatedPorts = append(interpolatedPorts, rc.ExprEval.Interpolate(ctx, port))
+			interpolatedPorts := make([]string, len(spec.Ports))
+			for i, port := range spec.Ports {
+				if interpolatedPorts[i], err = rc.ExprEval.Interpolate(ctx, port); err != nil {
+					return fmt.Errorf("unable to interpolate service %s ports: %w", serviceID, err)
+				}
 			}
 			exposedPorts, portBindings, err := nat.ParsePortSpecs(interpolatedPorts)
 			if err != nil {
 				return fmt.Errorf("failed to parse service %s ports: %w", serviceID, err)
 			}
+			serviceOptions, err := rc.ExprEval.Interpolate(ctx, spec.Options)
+			if err != nil {
+				return fmt.Errorf("unable to interpolate service %s options: %w", serviceID, err)
+			}
 
 			serviceContainerName := createContainerName(rc.jobContainerName(), serviceID)
 			c := newContainer(&container.NewContainerInput{
@@ -522,7 +579,7 @@ func (rc *RunContext) startJobContainer() common.Executor {
 				UsernsMode:      rc.Config.UsernsMode,
 				Platform:        rc.Config.ContainerArchitecture,
 				AutoRemove:      false, // so a dead service's log survives, cleanupJobResources removes it
-				WorkflowOptions: rc.ExprEval.Interpolate(ctx, spec.Options),
+				WorkflowOptions: serviceOptions,
 				NetworkMode:     networkName,
 				NetworkAliases:  []string{serviceID},
 				ExposedPorts:    exposedPorts,
@@ -538,6 +595,10 @@ func (rc *RunContext) startJobContainer() common.Executor {
 		// For Gitea, `jobContainerNetwork` should be the same as `networkName`
 		jobContainerNetwork := networkName
 
+		workflowOptions, err := rc.workflowOptions(ctx)
+		if err != nil {
+			return err
+		}
 		rc.JobContainer = newContainer(&container.NewContainerInput{
 			Cmd:             nil,
 			Entrypoint:      []string{"/bin/sleep", fmt.Sprint(rc.Config.ContainerMaxLifetime.Round(time.Second).Seconds())},
@@ -557,7 +618,7 @@ func (rc *RunContext) startJobContainer() common.Executor {
 			UsernsMode:      rc.Config.UsernsMode,
 			Platform:        rc.Config.ContainerArchitecture,
 			RunnerOptions:   rc.Config.ContainerOptions,
-			WorkflowOptions: rc.workflowOptions(ctx),
+			WorkflowOptions: workflowOptions,
 			AutoRemove:      true,
 			ValidVolumes:    rc.validVolumes(),
 			AllocatePTY:     rc.Config.AllocatePTY,
@@ -619,6 +680,12 @@ func (rc *RunContext) cleanupJobResources(networkName string, createAndDeleteNet
 				logger.Errorf("Error while cleaning services: %v", err)
 			}
 		}
+		if rc.dockerProxy != nil {
+			if err := rc.dockerProxy.Close(ctx); err != nil {
+				logger.Errorf("Error while removing what the job created: %v", err)
+			}
+			rc.dockerProxy = nil
+		}
 		if removeJobContainer {
 			// after the containers using them, services can hold these via `--volumes-from`
 			name := rc.jobContainerName()
@@ -882,6 +949,9 @@ func (rc *RunContext) captureJobContainerInfo() common.Executor {
 			return nil
 		}
 		rc.jobContainerID = info.ID
+		if source := info.Mounts[rc.githubWorkspace()]; source != "" {
+			rc.Env["GITEA_DOCKER_WORKSPACE"] = source
+		}
 		return nil
 	}
 }
@@ -928,7 +998,7 @@ func (rc *RunContext) interpolateOutputs() common.Executor {
 		outputs := make(map[string]string, len(rc.outputTemplate))
 		var err error
 		for k, v := range rc.outputTemplate {
-			if outputs[k], err = ee.interpolate(ctx, v); err != nil {
+			if outputs[k], err = ee.Interpolate(ctx, v); err != nil {
 				err = fmt.Errorf("failed to evaluate job output %q: %w", k, err)
 				break
 			}
@@ -948,7 +1018,7 @@ func (rc *RunContext) interpolateOutputs() common.Executor {
 func (rc *RunContext) startContainer() common.Executor {
 	return func(ctx context.Context) error {
 		var err error
-		if rc.IsHostEnv(ctx) {
+		if rc.IsHostEnv() {
 			err = rc.startHostEnvironment()(ctx)
 		} else {
 			err = rc.startJobContainer()(ctx)
@@ -978,10 +1048,8 @@ func (rc *RunContext) cleanupFailedStart(ctx context.Context) {
 	}
 }
 
-func (rc *RunContext) IsHostEnv(ctx context.Context) bool {
-	platform := rc.runsOnImage(ctx)
-	image := rc.containerImage(ctx)
-	return image == "" && strings.EqualFold(platform, "-self-hosted")
+func (rc *RunContext) IsHostEnv() bool {
+	return strings.EqualFold(rc.platformImage, "-self-hosted")
 }
 
 func (rc *RunContext) stopContainer() common.Executor {
@@ -1066,32 +1134,35 @@ func (rc *RunContext) Executor() (common.Executor, error) {
 	}, nil
 }
 
-func (rc *RunContext) containerImage(ctx context.Context) string {
-	job := rc.Run.Job()
-
-	c := job.Container()
-	if c != nil {
-		return rc.ExprEval.Interpolate(ctx, c.Image)
+func (rc *RunContext) containerImage(ctx context.Context) (string, error) {
+	c := rc.Run.Job().Container()
+	if c == nil {
+		return "", nil
 	}
-
-	return ""
+	image, err := rc.ExprEval.Interpolate(ctx, c.Image)
+	if err != nil {
+		return "", fmt.Errorf("unable to interpolate container.image: %w", err)
+	}
+	return image, nil
 }
 
-func (rc *RunContext) runsOnImage(ctx context.Context) string {
+func (rc *RunContext) runsOnImage(ctx context.Context) (string, error) {
 	if rc.Run.Job().RunsOn() == nil {
 		common.Logger(ctx).Errorf("'runs-on' key not defined in %s", rc.String())
 	}
 
-	job := rc.Run.Job()
-	runsOn := job.RunsOn()
+	runsOn := rc.Run.Job().RunsOn()
 	for i, v := range runsOn {
-		runsOn[i] = rc.ExprEval.Interpolate(ctx, v)
+		var err error
+		if runsOn[i], err = rc.ExprEval.Interpolate(ctx, v); err != nil {
+			return "", fmt.Errorf("unable to interpolate runs-on: %w", err)
+		}
 	}
 
 	if rc.Config.PlatformPicker != nil {
-		return rc.Config.PlatformPicker(runsOn)
+		return rc.Config.PlatformPicker(runsOn), nil
 	}
-	return ""
+	return "", nil
 }
 
 func (rc *RunContext) runsOnPlatformNames(ctx context.Context) []string {
@@ -1112,21 +1183,26 @@ func (rc *RunContext) runsOnPlatformNames(ctx context.Context) []string {
 	return model.RunsOnFromNode(rawRunsOn)
 }
 
-func (rc *RunContext) platformImage(ctx context.Context) string {
-	if containerImage := rc.containerImage(ctx); containerImage != "" {
-		return containerImage
+// resolvePlatformImage evaluates the job's image once, so every consumer sees the image the job started with.
+func (rc *RunContext) resolvePlatformImage(ctx context.Context) error {
+	image, err := rc.containerImage(ctx)
+	if err == nil && image == "" {
+		image, err = rc.runsOnImage(ctx)
 	}
-
-	return rc.runsOnImage(ctx)
+	rc.platformImage = image
+	return err
 }
 
-func (rc *RunContext) workflowOptions(ctx context.Context) string {
+func (rc *RunContext) workflowOptions(ctx context.Context) (string, error) {
 	c := rc.Run.Job().Container()
 	if c == nil {
-		return ""
+		return "", nil
 	}
-
-	return rc.ExprEval.Interpolate(ctx, c.Options)
+	options, err := rc.ExprEval.Interpolate(ctx, c.Options)
+	if err != nil {
+		return "", fmt.Errorf("unable to interpolate container.options: %w", err)
+	}
+	return options, nil
 }
 
 func (rc *RunContext) isEnabled(ctx context.Context) (bool, error) {
@@ -1156,8 +1232,10 @@ func (rc *RunContext) isEnabled(ctx context.Context) (bool, error) {
 		return true, nil
 	}
 
-	img := rc.platformImage(ctx)
-	if img == "" {
+	if err := rc.resolvePlatformImage(ctx); err != nil {
+		return false, err
+	}
+	if rc.platformImage == "" {
 		for _, platformName := range rc.runsOnPlatformNames(ctx) {
 			l.Infof("Skipping unsupported platform -- Try running with `-P %+v=...`", platformName)
 		}
@@ -1544,7 +1622,7 @@ func (rc *RunContext) imageOS(ctx context.Context) string {
 		// log that runs-on is missing.
 		return ""
 	}
-	if imageOS := imageOSFromImage(rc.platformImage(ctx)); imageOS != "" {
+	if imageOS := imageOSFromImage(rc.platformImage); imageOS != "" {
 		return imageOS
 	}
 
@@ -1606,14 +1684,23 @@ func (rc *RunContext) interpolateCredentials(ctx context.Context, credentials ma
 	}
 
 	ee := rc.NewExpressionEvaluator(ctx)
-	username := ee.Interpolate(ctx, credentials["username"])
-	if username == "" {
-		return "", "", errors.New("failed to interpolate " + prefix + "credentials.username")
+	interpolate := func(key string) (string, error) {
+		value, err := ee.Interpolate(ctx, credentials[key])
+		if err != nil {
+			return "", fmt.Errorf("failed to interpolate %scredentials.%s: %w", prefix, key, err)
+		}
+		if value == "" {
+			return "", fmt.Errorf("failed to interpolate %scredentials.%s", prefix, key)
+		}
+		return value, nil
 	}
-	password := ee.Interpolate(ctx, credentials["password"])
-	if password == "" {
-		return "", "", errors.New("failed to interpolate " + prefix + "credentials.password")
+	username, err := interpolate("username")
+	if err != nil {
+		return "", "", err
+	}
+	password, err := interpolate("password")
+	if err != nil {
+		return "", "", err
 	}
-
 	return username, password, nil
 }

act/runner/run_context_test.go

@@ -267,6 +267,7 @@ func startJobContainerInputs(t *testing.T, workflowYAML string, cfg *Config) []*
 		},
 	}
 	rc.ExprEval = rc.NewExpressionEvaluator(t.Context())
+	require.NoError(t, rc.resolvePlatformImage(t.Context()))
 
 	// the inputs are built before the missing daemon fails the first call
 	t.Setenv("DOCKER_HOST", "unix:///nonexistent.sock")
@@ -451,7 +452,8 @@ func TestRunContext_GetBindsAndMounts(t *testing.T) {
 					config := testcase.rc.Config
 					config.Workdir = testcase.name
 					config.BindWorkdir = bindWorkDir
-					gotbind, gotmount := rctemplate.GetBindsAndMounts()
+					gotbind, gotmount, err := rctemplate.GetBindsAndMounts()
+					require.NoError(t, err)
 
 					// Name binds/mounts are either/or
 					if config.BindWorkdir {
@@ -510,7 +512,8 @@ func TestRunContext_GetBindsAndMounts(t *testing.T) {
 			rc.Run.Workflow.Jobs = map[string]*model.Job{"job1": job}
 			rc.ExprEval = rc.NewExpressionEvaluator(context.Background())
 
-			gotbind, gotmount := rc.GetBindsAndMounts()
+			gotbind, gotmount, err := rc.GetBindsAndMounts()
+			require.NoError(t, err)
 			assert.Contains(t, gotbind, "/host/mame/roms:/root/.mame/roms:ro")
 			assert.NotContains(t, gotbind, "${{ secrets.MAME }}")
 			assert.NotContains(t, gotmount, "${{ secrets.MAME }}")
@@ -539,7 +542,8 @@ func TestRunContext_GetBindsAndMounts(t *testing.T) {
 				rc.Run.JobID = "job1"
 				rc.Run.Workflow.Jobs = map[string]*model.Job{"job1": job}
 
-				gotbind, gotmount := rc.GetBindsAndMounts()
+				gotbind, gotmount, err := rc.GetBindsAndMounts()
+				require.NoError(t, err)
 
 				if len(testcase.wantbind) > 0 {
 					assert.Contains(t, gotbind, testcase.wantbind)
@@ -574,11 +578,13 @@ func TestRunContext_GetBindsAndMounts(t *testing.T) {
 			Config: &Config{},
 		}
 
-		_, gotmount := rc.GetBindsAndMounts()
+		_, gotmount, err := rc.GetBindsAndMounts()
+		require.NoError(t, err)
 		assert.NotContains(t, gotmount, sharedToolCacheVolume)
 
 		rc.Config.SharedToolCache = true
-		_, gotmount = rc.GetBindsAndMounts()
+		_, gotmount, err = rc.GetBindsAndMounts()
+		require.NoError(t, err)
 		assert.Equal(t, container.DefaultToolCache, gotmount[sharedToolCacheVolume])
 	})
 }
@@ -604,6 +610,11 @@ func TestRunContextValidVolumes(t *testing.T) {
 	// a job may mount it only while the runner does
 	rc.Config.SharedToolCache = false
 	assert.NotContains(t, rc.validVolumes(), sharedToolCacheVolume)
+
+	rc.Config.Workdir = "/workspace/1/owner/repo"
+	assert.NotContains(t, rc.validVolumes(), rc.Config.Workdir)
+	rc.Config.BindWorkdir = true
+	assert.Contains(t, rc.validVolumes(), rc.Config.Workdir)
 }
 
 func TestCleanupJobResourcesCleansServicesWithoutJobContainer(t *testing.T) {
@@ -655,8 +666,10 @@ func TestInterpolateOutputsIsPerMatrixCombo(t *testing.T) {
 	r := &runnerImpl{config: &Config{}}
 	ctx := context.Background()
 
-	rcA := r.newRunContext(ctx, run, map[string]any{"v": "a"})
-	rcB := r.newRunContext(ctx, run, map[string]any{"v": "b"})
+	rcA, err := r.newRunContext(ctx, run, map[string]any{"v": "a"})
+	require.NoError(t, err)
+	rcB, err := r.newRunContext(ctx, run, map[string]any{"v": "b"})
+	require.NoError(t, err)
 
 	require.NoError(t, rcA.interpolateOutputs()(ctx))
 	require.NoError(t, rcB.interpolateOutputs()(ctx))
@@ -1281,6 +1294,29 @@ func TestGetJobContextReportsContainers(t *testing.T) {
 	}, jobContext.Services)
 }
 
+func TestCaptureJobContainerInfoExportsDockerWorkspace(t *testing.T) {
+	job := &containerMock{}
+	job.On("Inspect", mock.Anything).Return(&container.Info{
+		ID:     "job-container-id",
+		Mounts: map[string]string{"/workspace/owner/repo": "/var/lib/docker/volumes/job/_data"},
+	}, nil)
+	rc := &RunContext{
+		Config:       &Config{Workdir: "/workspace/owner/repo/"},
+		Env:          map[string]string{},
+		JobContainer: job,
+	}
+
+	require.NoError(t, rc.captureJobContainerInfo()(context.Background()))
+
+	assert.Equal(t, "job-container-id", rc.jobContainerID)
+	assert.Equal(t, "/var/lib/docker/volumes/job/_data", rc.Env["GITEA_DOCKER_WORKSPACE"])
+
+	rc.Config.Workdir = "/elsewhere"
+	rc.Env = map[string]string{}
+	require.NoError(t, rc.captureJobContainerInfo()(context.Background()))
+	assert.NotContains(t, rc.Env, "GITEA_DOCKER_WORKSPACE")
+}
+
 // A job that never started a container reports an empty context, not a placeholder.
 func TestGetJobContextWithoutContainer(t *testing.T) {
 	jobContext := (&RunContext{}).getJobContext()
@@ -1329,12 +1365,14 @@ func TestRunContextImageOS(t *testing.T) {
 	t.Run("prefers the release in the resolved image tag", func(t *testing.T) {
 		rc := createRunsOnRunContext(t, "ubuntu-latest")
 		rc.Config.PlatformPicker = func([]string) string { return "docker.gitea.com/runner-images:ubuntu-24.04" }
+		require.NoError(t, rc.resolvePlatformImage(ctx))
 		assert.Equal(t, "ubuntu24", rc.imageOS(ctx))
 	})
 
 	t.Run("falls back to the runs-on label", func(t *testing.T) {
 		rc := createRunsOnRunContext(t, "ubuntu-22.04")
 		rc.Config.PlatformPicker = func([]string) string { return "some-image" }
+		require.NoError(t, rc.resolvePlatformImage(ctx))
 		assert.Equal(t, "ubuntu22", rc.imageOS(ctx))
 	})
 

act/runner/runner.go

@@ -198,7 +198,10 @@ func (runner *runnerImpl) NewPlanExecutor(plan *model.Plan) common.Executor {
 					log.Debugf("Job.Strategy.MaxParallelString: %v", job.Strategy.MaxParallelString)
 					log.Debugf("Job.Strategy.RawMatrix: %v", job.Strategy.RawMatrix)
 
-					strategyRc := runner.newRunContext(ctx, run, nil)
+					strategyRc, err := runner.newRunContext(ctx, run, nil)
+					if err != nil {
+						return err
+					}
 					// Resolve template expressions in the matrix node before Matrix() is called.
 					// On failure the literal string is kept and normalizeMatrixValue wraps it as a fallback.
 					if err := strategyRc.NewExpressionEvaluator(ctx).EvaluateYamlNode(ctx, &job.Strategy.RawMatrix); err != nil {
@@ -230,7 +233,10 @@ func (runner *runnerImpl) NewPlanExecutor(plan *model.Plan) common.Executor {
 				log.Infof("Running job with maxParallel=%d for %d matrix combinations", maxParallel, len(matrixes))
 
 				for i, matrix := range matrixes {
-					rc := runner.newRunContext(ctx, run, matrix)
+					rc, err := runner.newRunContext(ctx, run, matrix)
+					if err != nil {
+						return err
+					}
 					rc.JobName = rc.Name
 					if len(matrixes) > 1 {
 						rc.Name = fmt.Sprintf("%s-%d", rc.Name, i+1)
@@ -315,7 +321,7 @@ func handleFailure(plan *model.Plan) common.Executor {
 	}
 }
 
-func (runner *runnerImpl) newRunContext(ctx context.Context, run *model.Run, matrix map[string]any) *RunContext {
+func (runner *runnerImpl) newRunContext(ctx context.Context, run *model.Run, matrix map[string]any) (*RunContext, error) {
 	rc := &RunContext{
 		Config:      runner.config,
 		Run:         run,
@@ -324,15 +330,18 @@ func (runner *runnerImpl) newRunContext(ctx context.Context, run *model.Run, mat
 		Matrix:      matrix,
 		caller:      runner.caller,
 	}
+	if err := rc.resolveWorkflowCall(ctx); err != nil {
+		return nil, err
+	}
 	rc.ExprEval = rc.NewExpressionEvaluator(ctx)
-	rc.Name = rc.maskSecrets(rc.ExprEval.Interpolate(ctx, run.String()))
+	rc.Name = rc.maskSecrets(rc.ExprEval.InterpolateName(ctx, run.String()))
 	// Snapshot the job's pristine output expressions now, before any matrix combo runs and
 	// rewrites the shared Job.Outputs (see interpolateOutputs).
 	if job := run.Job(); job != nil {
 		rc.outputTemplate = maps.Clone(job.Outputs)
 	}
 
-	return rc
+	return rc, nil
 }
 
 // For Gitea

act/runner/step.go

@@ -11,6 +11,7 @@ import (
 	"path"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"gitea.com/gitea/runner/act/common"
@@ -82,9 +83,11 @@ func runStepExecutor(step step, stage stepStage, executor common.Executor) commo
 			rc.StepResults[rc.CurrentStep] = stepResult
 		}
 
-		setupEnv(ctx, step)
-
-		runStep, err := isStepEnabled(ctx, ifExpression, step, stage)
+		err := setupEnv(ctx, step)
+		var runStep bool
+		if err == nil {
+			runStep, err = isStepEnabled(ctx, ifExpression, step, stage)
+		}
 		if err != nil {
 			stepResult.Conclusion = model.StepStatusFailure
 			stepResult.Outcome = model.StepStatusFailure
@@ -99,7 +102,7 @@ func runStepExecutor(step step, stage stepStage, executor common.Executor) commo
 			return nil
 		}
 
-		stepString := rc.ExprEval.Interpolate(ctx, stepModel.String())
+		stepString := rc.ExprEval.InterpolateName(ctx, stepModel.String())
 		if strings.Contains(stepString, "::add-mask::") {
 			stepString = "add-mask command"
 		}
@@ -221,8 +224,10 @@ func runStepExecutor(step step, stage stepStage, executor common.Executor) commo
 }
 
 func evaluateStepTimeout(ctx context.Context, exprEval *expressionEvaluator, stepModel *model.Step) (context.Context, context.CancelFunc) {
-	timeout := exprEval.Interpolate(ctx, stepModel.TimeoutMinutes)
-	if timeout != "" {
+	timeout, err := exprEval.Interpolate(ctx, stepModel.TimeoutMinutes)
+	if err != nil {
+		common.Logger(ctx).Errorf("An error occurred when attempting to determine the step timeout: %s", err)
+	} else if timeout != "" {
 		if timeOutMinutes, err := strconv.ParseInt(timeout, 10, 64); err == nil && timeOutMinutes > 0 {
 			return context.WithTimeout(ctx, time.Duration(timeOutMinutes)*time.Minute)
 		}
@@ -230,27 +235,33 @@ func evaluateStepTimeout(ctx context.Context, exprEval *expressionEvaluator, ste
 	return ctx, func() {}
 }
 
-func setupEnv(ctx context.Context, step step) {
+func setupEnv(ctx context.Context, step step) error {
 	rc := step.getRunContext()
 
 	mergeEnv(ctx, step)
 	// merge step env last, since it should not be overwritten
 	mergeIntoMap(step, step.getEnv(), step.getStepModel().GetEnv())
 
+	var err error
 	exprEval := rc.NewExpressionEvaluator(ctx)
 	for k, v := range *step.getEnv() {
 		if !strings.HasPrefix(k, "INPUT_") {
-			(*step.getEnv())[k] = exprEval.Interpolate(ctx, v)
+			if (*step.getEnv())[k], err = exprEval.Interpolate(ctx, v); err != nil {
+				return fmt.Errorf("unable to interpolate env %s: %w", k, err)
+			}
 		}
 	}
 	// after we have an evaluated step context, update the expressions evaluator with a new env context
 	// you can use step level env in the with property of a uses construct
-	exprEval = rc.NewExpressionEvaluatorWithEnv(ctx, *step.getEnv())
+	inputEval := sync.OnceValue(func() *expressionEvaluator { return rc.NewExpressionEvaluatorWithEnv(ctx, *step.getEnv()) })
 	for k, v := range *step.getEnv() {
 		if strings.HasPrefix(k, "INPUT_") {
-			(*step.getEnv())[k] = exprEval.Interpolate(ctx, v)
+			if (*step.getEnv())[k], err = inputEval().Interpolate(ctx, v); err != nil {
+				return fmt.Errorf("unable to interpolate env %s: %w", k, err)
+			}
 		}
 	}
+	return nil
 }
 
 func mergeEnv(ctx context.Context, step step) {

act/runner/step_action_local.go

@@ -122,15 +122,19 @@ func (sal *stepActionLocal) getActionModel() *model.Action {
 	return sal.action
 }
 
-func (sal *stepActionLocal) getCompositeRunContext(ctx context.Context) *RunContext {
+func (sal *stepActionLocal) getCompositeRunContext(ctx context.Context) (*RunContext, error) {
 	if sal.compositeRunContext == nil {
 		actionDir := filepath.Join(sal.RunContext.Config.Workdir, sal.Step.Uses)
 		_, containerActionDir := getContainerActionPaths(sal.getStepModel(), actionDir, sal.RunContext)
 
-		sal.compositeRunContext = newCompositeRunContext(ctx, sal.RunContext, sal, containerActionDir)
-		sal.compositeSteps = sal.compositeRunContext.compositeExecutor(sal.action)
+		compositeRunContext, err := newCompositeRunContext(ctx, sal.RunContext, sal, containerActionDir)
+		if err != nil {
+			return nil, err
+		}
+		sal.compositeRunContext = compositeRunContext
+		sal.compositeSteps = compositeRunContext.compositeExecutor(sal.action)
 	}
-	return sal.compositeRunContext
+	return sal.compositeRunContext, nil
 }
 
 func (sal *stepActionLocal) getCompositeSteps() *compositeSteps {

act/runner/step_action_remote.go

@@ -51,7 +51,11 @@ func (sar *stepActionRemote) prepareActionExecutor() common.Executor {
 		// Since actions can specify the download source via a url prefix.
 		// The prefix may contain some sensitive information that needs to be stored in secrets,
 		// so we need to interpolate the expression value for uses first.
-		sar.Step.Uses = sar.RunContext.NewExpressionEvaluator(ctx).Interpolate(ctx, sar.Step.Uses)
+		uses, err := sar.RunContext.NewExpressionEvaluator(ctx).Interpolate(ctx, sar.Step.Uses)
+		if err != nil {
+			return fmt.Errorf("unable to interpolate uses: %w", err)
+		}
+		sar.Step.Uses = uses
 
 		github := sar.getGithubContext(ctx) // read before remoteAction is set, so `$/` resolves against the enclosing action
 		if strings.HasPrefix(sar.Step.Uses, selfRepoPrefix) {
@@ -160,9 +164,12 @@ func (sar *stepActionRemote) main() common.Executor {
 					common.Logger(ctx).Debugf("Skipping local actions/checkout because you bound your workspace")
 					return nil
 				}
-				eval := sar.RunContext.NewExpressionEvaluator(ctx)
-				copyToPath := path.Join(sar.RunContext.JobContainer.ToContainerPath(sar.RunContext.Config.Workdir), eval.Interpolate(ctx, sar.Step.With["path"]))
-				return sar.RunContext.JobContainer.CopyDir(copyToPath, sar.RunContext.Config.Workdir+string(filepath.Separator)+".", sar.RunContext.Config.UseGitIgnore)(ctx)
+				checkoutPath, err := sar.RunContext.NewExpressionEvaluator(ctx).Interpolate(ctx, sar.Step.With["path"])
+				if err != nil {
+					return fmt.Errorf("unable to interpolate with.path: %w", err)
+				}
+				copyToPath := path.Join(sar.RunContext.JobContainer.ToContainerPath(sar.RunContext.Config.Workdir), checkoutPath)
+				return sar.RunContext.JobContainer.CopyDir(copyToPath, sar.RunContext.Config.Workdir+string(filepath.Separator)+".", sar.RunContext.Config.UseGitIgnore, false)(ctx)
 			}
 
 			return sar.runAction(sar, sar.actionDir(), sar.remoteAction)(ctx)
@@ -229,14 +236,18 @@ func (sar *stepActionRemote) getActionModel() *model.Action {
 	return sar.action
 }
 
-func (sar *stepActionRemote) getCompositeRunContext(ctx context.Context) *RunContext {
+func (sar *stepActionRemote) getCompositeRunContext(ctx context.Context) (*RunContext, error) {
 	if sar.compositeRunContext == nil {
 		actionDir := sar.actionDir()
 		actionLocation := path.Join(actionDir, sar.remoteAction.Path)
 		_, containerActionDir := getContainerActionPaths(sar.getStepModel(), actionLocation, sar.RunContext)
 
-		sar.compositeRunContext = newCompositeRunContext(ctx, sar.RunContext, sar, containerActionDir)
-		sar.compositeSteps = sar.compositeRunContext.compositeExecutor(sar.action)
+		compositeRunContext, err := newCompositeRunContext(ctx, sar.RunContext, sar, containerActionDir)
+		if err != nil {
+			return nil, err
+		}
+		sar.compositeRunContext = compositeRunContext
+		sar.compositeSteps = compositeRunContext.compositeExecutor(sar.action)
 	} else {
 		// Re-evaluate environment here. For remote actions the environment
 		// need to be re-created for every stage (pre, main, post) as there
@@ -244,11 +255,14 @@ func (sar *stepActionRemote) getCompositeRunContext(ctx context.Context) *RunCon
 		// stages are executed. (e.g. the output of another action is the
 		// input for this action during the main stage, but the env
 		// was already created during the pre stage)
-		env := evaluateCompositeInputAndEnv(ctx, sar.RunContext, sar)
+		env, err := evaluateCompositeInputAndEnv(ctx, sar.RunContext, sar)
+		if err != nil {
+			return nil, err
+		}
 		sar.compositeRunContext.setCompositeActionEnv(env)
 		sar.compositeRunContext.ExtraPath = sar.RunContext.ExtraPath
 	}
-	return sar.compositeRunContext
+	return sar.compositeRunContext, nil
 }
 
 func (sar *stepActionRemote) getCompositeSteps() *compositeSteps {

act/runner/step_action_remote_test.go

@@ -254,7 +254,8 @@ func TestStepActionRemote(t *testing.T) {
 
 		for _, value := range []string{"first", "second"} {
 			step.env["INPUT_SHARED"] = value
-			composite := step.getCompositeRunContext(t.Context())
+			composite, err := step.getCompositeRunContext(t.Context())
+			require.NoError(t, err)
 			assert.Equal(t, map[string]any{"shared": value}, composite.actionInputs)
 			assert.NotContains(t, composite.Env, "INPUT_SHARED")
 		}

act/runner/step_docker.go

@@ -6,6 +6,7 @@ package runner
 
 import (
 	"context"
+	"fmt"
 	"strings"
 
 	"gitea.com/gitea/runner/act/common"
@@ -58,17 +59,28 @@ func (sd *stepDocker) runUsesContainer() common.Executor {
 	return func(ctx context.Context) error {
 		image := strings.TrimPrefix(step.Uses, "docker://")
 		eval := rc.NewExpressionEvaluator(ctx)
-		cmd, err := shellquote.Split(eval.Interpolate(ctx, step.With["args"]))
+		args, err := eval.Interpolate(ctx, step.With["args"])
+		if err != nil {
+			return fmt.Errorf("unable to interpolate with.args: %w", err)
+		}
+		cmd, err := shellquote.Split(args)
 		if err != nil {
 			return err
 		}
 
 		var entrypoint []string
-		if entry := eval.Interpolate(ctx, step.With["entrypoint"]); entry != "" {
+		entry, err := eval.Interpolate(ctx, step.With["entrypoint"])
+		if err != nil {
+			return fmt.Errorf("unable to interpolate with.entrypoint: %w", err)
+		}
+		if entry != "" {
 			entrypoint = []string{entry}
 		}
 
-		stepContainer := newStepContainer(ctx, sd, image, cmd, entrypoint, "")
+		stepContainer, err := newStepContainer(ctx, sd, image, cmd, entrypoint, "")
+		if err != nil {
+			return err
+		}
 
 		return common.NewPipelineExecutor(
 			stepContainer.Pull(rc.Config.ForcePull),

act/runner/step_docker_test.go

@@ -16,6 +16,7 @@ import (
 	"gitea.dev/actionslib/pkg/model"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
 )
 
 func TestStepDockerMain(t *testing.T) {
@@ -144,7 +145,7 @@ func TestStepDockerNewStepContainerAllocatePTY(t *testing.T) {
 			}
 			sd.RunContext.ExprEval = sd.RunContext.NewExpressionEvaluator(ctx)
 
-			_ = newStepContainer(ctx, sd, "node:14", []string{"echo", "hi"}, nil, "")
+			_, _ = newStepContainer(ctx, sd, "node:14", []string{"echo", "hi"}, nil, "")
 			assert.Equal(t, tc.allocPTY, captured.AllocatePTY)
 		})
 	}
@@ -210,10 +211,10 @@ func TestStepDockerNewStepContainerNetworkMode(t *testing.T) {
 			}
 			sd.RunContext.ExprEval = sd.RunContext.NewExpressionEvaluator(ctx)
 
-			assert.Equal(t, tc.expectDefault, sd.RunContext.IsHostEnv(ctx),
-				"IsHostEnv mismatch for platform %q", tc.platform)
+			require.NoError(t, sd.RunContext.resolvePlatformImage(ctx))
+			assert.Equal(t, tc.expectDefault, sd.RunContext.IsHostEnv(), "IsHostEnv mismatch for platform %q", tc.platform)
 
-			_ = newStepContainer(ctx, sd, "alpine:3.20", []string{"echo", "hello"}, nil, "")
+			_, _ = newStepContainer(ctx, sd, "alpine:3.20", []string{"echo", "hello"}, nil, "")
 
 			if tc.expectDefault {
 				assert.Equal(t, "default", captured.NetworkMode,

act/runner/step_run.go

@@ -254,12 +254,21 @@ func getScriptName(rc *RunContext, step *model.Step) string {
 // OCI runtime exec failed: exec failed: container_linux.go:380: starting container process caused: exec: "${{": executable file not found in $PATH: unknown
 func (sr *stepRun) setupShellCommand(ctx context.Context) (name, script string, err error) {
 	logger := common.Logger(ctx)
-	implicitShell := sr.setupShell(ctx)
-	sr.setupWorkingDirectory(ctx)
+	eval := sr.RunContext.NewStepExpressionEvaluator(ctx, sr)
+	implicitShell, err := sr.setupShell(ctx, eval)
+	if err != nil {
+		return "", "", err
+	}
+	if err := sr.setupWorkingDirectory(ctx, eval); err != nil {
+		return "", "", err
+	}
 
 	step := sr.Step
 
-	script = sr.RunContext.NewStepExpressionEvaluator(ctx, sr).Interpolate(ctx, step.Run)
+	script, err = eval.Interpolate(ctx, step.Run)
+	if err != nil {
+		return "", "", fmt.Errorf("unable to interpolate the run script: %w", err)
+	}
 	sr.interpolatedScript = script
 
 	// GitHub matches the built-in names case-insensitively, so `shell: PWSH` is valid
@@ -313,19 +322,21 @@ func (sr *stepRun) setupShellCommand(ctx context.Context) (name, script string,
 	return name, script, err
 }
 
-func (sr *stepRun) setupShell(ctx context.Context) bool {
+func (sr *stepRun) setupShell(ctx context.Context, eval *expressionEvaluator) (bool, error) {
 	rc := sr.RunContext
 	step := sr.Step
 
-	if step.Shell == "" {
-		step.Shell = rc.Run.Job().Defaults.Run.Shell
+	shell, err := eval.Interpolate(ctx, step.Shell)
+	if err != nil {
+		return false, fmt.Errorf("unable to interpolate the shell: %w", err)
 	}
-
-	step.Shell = rc.NewStepExpressionEvaluator(ctx, sr).Interpolate(ctx, step.Shell)
-
-	if step.Shell == "" {
-		step.Shell = rc.Run.Workflow.Defaults.Run.Shell
+	if shell == "" {
+		shell = rc.jobRunDefaults.Shell
 	}
+	if shell == "" {
+		shell = rc.Run.Workflow.Defaults.Run.Shell
+	}
+	step.Shell = shell
 
 	implicitShell := step.Shell == ""
 	if implicitShell {
@@ -349,7 +360,7 @@ func (sr *stepRun) setupShell(ctx context.Context) bool {
 			}
 		}
 	}
-	return implicitShell
+	return implicitShell, nil
 }
 
 // containerHasBash probes once per job, else every implicit-shell step pays for an exec.
@@ -364,23 +375,19 @@ func (rc *RunContext) containerHasBash(ctx context.Context, env map[string]strin
 	return *top.hasBash
 }
 
-func (sr *stepRun) setupWorkingDirectory(ctx context.Context) {
+func (sr *stepRun) setupWorkingDirectory(ctx context.Context, eval *expressionEvaluator) error {
 	rc := sr.RunContext
-	step := sr.Step
-	var workingdirectory string
-
-	if step.WorkingDirectory == "" {
-		workingdirectory = rc.Run.Job().Defaults.Run.WorkingDirectory
-	} else {
-		workingdirectory = step.WorkingDirectory
+	workingdirectory, err := eval.Interpolate(ctx, sr.Step.WorkingDirectory)
+	if err != nil {
+		return fmt.Errorf("unable to interpolate the working directory: %w", err)
 	}
-
-	// jobs can receive context values, so we interpolate
-	workingdirectory = rc.NewStepExpressionEvaluator(ctx, sr).Interpolate(ctx, workingdirectory)
-
-	// but top level keys in workflow file like `defaults` or `env` can't
+	if workingdirectory == "" {
+		workingdirectory = rc.jobRunDefaults.WorkingDirectory
+	}
+	// top level keys in workflow file like `defaults` or `env` can't hold expressions
 	if workingdirectory == "" {
 		workingdirectory = rc.Run.Workflow.Defaults.Run.WorkingDirectory
 	}
 	sr.WorkingDirectory = workingdirectory
+	return nil
 }

act/runner/step_run_test.go

@@ -6,6 +6,7 @@ package runner
 
 import (
 	"bytes"
+	"cmp"
 	"context"
 	"io"
 	"os"
@@ -42,17 +43,12 @@ func TestStepRun(t *testing.T) {
 				JobID: "1",
 				Workflow: &model.Workflow{
 					Jobs: map[string]*model.Job{
-						"1": {
-							Defaults: model.Defaults{
-								Run: model.RunDefaults{
-									Shell: "bash",
-								},
-							},
-						},
+						"1": {},
 					},
 				},
 			},
-			JobContainer: cm,
+			JobContainer:   cm,
+			jobRunDefaults: model.RunDefaults{Shell: "bash"},
 		},
 		Step: &model.Step{
 			ID:               "1",
@@ -84,13 +80,13 @@ func TestStepRun(t *testing.T) {
 
 func TestStepRunShellParity(t *testing.T) {
 	tests := []struct {
-		name, shell, workingDir string
-		env                     map[string]string
-		host                    bool
-		probeErr                error
-		wantExt                 string
-		wantCmd                 []string
-		wantErr                 string
+		name, run, shell, workingDir string
+		env                          map[string]string
+		host                         bool
+		probeErr                     error
+		wantExt                      string
+		wantCmd                      []string
+		wantErr                      string
 	}{
 		{
 			name:    "implicit host bash",
@@ -130,6 +126,21 @@ func TestStepRunShellParity(t *testing.T) {
 			wantExt:    ".py",
 			wantCmd:    []string{"python", "/var/run/act/workflow/1.py"},
 		},
+		{
+			name:    "run expression without a context",
+			run:     "echo ${{ COMMIT_SHA }}",
+			wantErr: "unable to interpolate the run script:",
+		},
+		{
+			name:    "shell expression without a context",
+			shell:   "${{ SHELL }}",
+			wantErr: "unable to interpolate the shell:",
+		},
+		{
+			name:       "working directory expression without a context",
+			workingDir: "${{ DIR }}",
+			wantErr:    "unable to interpolate the working directory:",
+		},
 	}
 
 	for _, test := range tests {
@@ -156,13 +167,13 @@ func TestStepRunShellParity(t *testing.T) {
 					Run:          &model.Run{JobID: "1", Workflow: &model.Workflow{Jobs: map[string]*model.Job{"1": {}}}},
 					JobContainer: jobContainer,
 				},
-				Step: &model.Step{ID: "1", Run: "echo hi", Shell: test.shell, WorkingDirectory: test.workingDir},
+				Step: &model.Step{ID: "1", Run: cmp.Or(test.run, "echo hi"), Shell: test.shell, WorkingDirectory: test.workingDir},
 				env:  test.env,
 			}
 
 			name, script, err := sr.setupShellCommand(t.Context())
 			if test.wantErr != "" {
-				require.EqualError(t, err, test.wantErr)
+				require.ErrorContains(t, err, test.wantErr)
 				return
 			}
 			require.NoError(t, err)

act/runner/step_test.go

@@ -160,7 +160,7 @@ func TestSetupEnv(t *testing.T) {
 	sm.On("getStepModel").Return(step)
 	sm.On("getEnv").Return(&env)
 
-	setupEnv(context.Background(), sm)
+	require.NoError(t, setupEnv(context.Background(), sm))
 
 	// These are commit or system specific
 	delete(env, "GITHUB_REF")

go.mod

@@ -102,6 +102,6 @@ require (
 	go.opentelemetry.io/otel/metric v1.45.0 // indirect
 	go.opentelemetry.io/otel/trace v1.45.0 // indirect
 	go.yaml.in/yaml/v3 v3.0.5 // indirect
-	golang.org/x/crypto v0.55.0 // indirect
+	golang.org/x/crypto v0.56.0 // indirect
 	gopkg.in/warnings.v0 v0.1.2 // indirect
 )

go.sum

@@ -234,8 +234,8 @@ go.yaml.in/yaml/v3 v3.0.5/go.mod h1:HVTZu1O7/Vkt2N+BFy8Zza+lnLsABggaTM2ZpNIGuKg=
 go.yaml.in/yaml/v4 v4.0.0-rc.3 h1:3h1fjsh1CTAPjW7q/EMe+C8shx5d8ctzZTrLcs/j8Go=
 go.yaml.in/yaml/v4 v4.0.0-rc.3/go.mod h1:aZqd9kCMsGL7AuUv/m/PvWLdg5sjJsZ4oHDEnfPPfY0=
 golang.org/x/crypto v0.0.0-20220622213112-05595931fe9d/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
-golang.org/x/crypto v0.55.0 h1:+KWHjbgOaAQ66dh/YlkZKHlz9ZUlq61AFirAR9ntP8M=
-golang.org/x/crypto v0.55.0/go.mod h1:uq0V9dE/fzQuJtbnL+2EhWOE63vo164FY8xqEnV9xis=
+golang.org/x/crypto v0.56.0 h1:GUh5Ii4J5jtcseSMiRqr1jXCNHoxjeV9Fmekc2oLy6Y=
+golang.org/x/crypto v0.56.0/go.mod h1:OMW5y6CY9l38uPLmxU6l6pwcXp1obtLo3e6gT7gQR2I=
 golang.org/x/exp v0.0.0-20260410095643-746e56fc9e2f h1:W3F4c+6OLc6H2lb//N1q4WpJkhzJCK5J6kUi1NTVXfM=
 golang.org/x/exp v0.0.0-20260410095643-746e56fc9e2f/go.mod h1:J1xhfL/vlindoeF/aINzNzt2Bket5bjo9sdOYzOsU80=
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=

internal/pkg/config/config.example.yaml

@@ -256,11 +256,10 @@ container:
   #require_docker: false
   # Timeout to wait for the docker daemon to be reachable, if docker is required by require_docker or runner
   #docker_timeout: 0s
-  # Bind the workspace to the host filesystem instead of using Docker volumes.
-  # This is required for Docker-in-Docker (DinD) setups when jobs use docker compose
-  # with bind mounts (e.g., ".:/app"), as volume-based workspaces are not accessible
-  # from the DinD daemon's filesystem. When enabled, ensure the workspace parent
-  # directory is also mounted into the runner container and listed in valid_volumes.
+  # Mount the workspace from a host directory instead of a Docker volume, so jobs
+  # can bind-mount it by its own path into sibling containers (".:/app" in docker
+  # compose). Not needed when workflows use the GITEA_DOCKER_WORKSPACE variable.
+  # The workspace parent directory must be mounted into the runner container.
   #bind_workdir: false
   # How long a job waits for a service container that declares a healthcheck to become
   # healthy. A negative value (e.g. -1s) starts the steps without waiting.

internal/pkg/config/config.go

@@ -157,7 +157,7 @@ type Container struct {
 	ForceRebuild         bool                          `yaml:"force_rebuild"`          // Rebuild docker image(s) even if already present
 	RequireDocker        bool                          `yaml:"require_docker"`         // Always require a reachable docker daemon, even if not required by runner
 	DockerTimeout        time.Duration                 `yaml:"docker_timeout"`         // Timeout to wait for the docker daemon to be reachable, if docker is required by require_docker or runner
-	BindWorkdir          bool                          `yaml:"bind_workdir"`           // BindWorkdir binds the workspace to the host filesystem instead of using Docker volumes. Required for DinD when jobs use docker compose with bind mounts.
+	BindWorkdir          bool                          `yaml:"bind_workdir"`           // BindWorkdir mounts the workspace from a host directory instead of a Docker volume.
 	ServiceReadyTimeout  time.Duration                 `yaml:"service_ready_timeout"`  // ServiceReadyTimeout bounds how long a job waits for a service container that declares a healthcheck to report healthy. Negative disables waiting.
 }