Convert errors to JSON

Signed-off-by: Matt Prahl <mprahl@redhat.com>
Signed-off-by: Nils Philippsen <nils@redhat.com>

rida/__init__.py

@@ -22,6 +22,7 @@
 # SOFTWARE.
 #
 # Written by Petr Šabata <contyk@redhat.com>
+#            Matt Prahl <mprahl@redhat.com>
 
 """The module build orchestrator for Modularity.
 
@@ -45,6 +46,8 @@ from flask_sqlalchemy import SQLAlchemy
 from os import sys
 import rida.logger
 from logging import getLogger
+from rida.errors import (ValidationError, Unauthorized, UnprocessableEntity,
+                         Conflict, NotFound, Forbidden, json_error)
 
 app = Flask(__name__)
 app.config.from_envvar("RIDA_SETTINGS", silent=True)
@@ -58,6 +61,47 @@ else:
 db = SQLAlchemy(app)
 
 
+@app.errorhandler(ValidationError)
+def validationerror_error(e):
+    """Flask error handler for ValidationError exceptions"""
+    return json_error(400, 'Bad Request', e.args[0])
+
+
+@app.errorhandler(Unauthorized)
+def unauthorized_error(e):
+    """Flask error handler for NotAuthorized exceptions"""
+    return json_error(401, 'Unauthorized', e.args[0])
+
+
+@app.errorhandler(Forbidden)
+def forbidden_error(e):
+    """Flask error handler for Forbidden exceptions"""
+    return json_error(403, 'Forbidden', e.args[0])
+
+
+@app.errorhandler(RuntimeError)
+def runtimeerror_error(e):
+    """Flask error handler for RuntimeError exceptions"""
+    return json_error(500, 'Internal Server Error', e.args[0])
+
+
+@app.errorhandler(UnprocessableEntity)
+def unprocessableentity_error(e):
+    """Flask error handler for UnprocessableEntity exceptions"""
+    return json_error(422, 'Unprocessable Entity', e.args[0])
+
+
+@app.errorhandler(Conflict)
+def conflict_error(e):
+    """Flask error handler for Conflict exceptions"""
+    return json_error(409, 'Conflict', e.args[0])
+
+
+@app.errorhandler(NotFound)
+def notfound_error(e):
+    """Flask error handler for Conflict exceptions"""
+    return json_error(404, 'Not Found', e.args[0])
+
 import rida.config
 conf = rida.config.from_app_config()
 rida.logger.init_logging(conf)

rida/errors.py

@@ -20,6 +20,37 @@
 #
 # Written by Matt Prahl <mprahl@redhat.com>
 """ Defines custom exceptions and error handling functions """
+from flask import jsonify
+
 
 class ValidationError(ValueError):
     pass
+
+
+class Unauthorized(ValueError):
+    pass
+
+
+class Forbidden(ValueError):
+    pass
+
+
+class UnprocessableEntity(ValueError):
+    pass
+
+
+class Conflict(ValueError):
+    pass
+
+
+class NotFound(ValueError):
+    pass
+
+
+def json_error(status, error, message):
+    response = jsonify(
+        {'status': status,
+         'error': error,
+         'message': message})
+    response.status_code = status
+    return response

rida/scm.py

@@ -36,6 +36,7 @@ import tempfile
 import shutil
 
 from rida import log
+from rida.errors import Unauthorized, ValidationError
 import rida.utils
 
 
@@ -62,7 +63,7 @@ class SCM(object):
 
         :param str url: The unmodified scmurl
         :param list allowed_scm: The list of allowed SCMs, optional
-        :raises: RuntimeError
+        :raises: Unauthorized or ValidationError
         """
 
         if allowed_scm:
@@ -70,7 +71,8 @@ class SCM(object):
                 if url.startswith(allowed):
                     break
                 else:
-                    raise RuntimeError('%s is not in the list of allowed SCMs' % url)
+                    raise Unauthorized(
+                        '%s is not in the list of allowed SCMs' % url)
 
         self.url = url
 
@@ -79,7 +81,7 @@ class SCM(object):
                 self.scheme = scmtype
                 break
         else:
-            raise RuntimeError('Invalid SCM URL: %s' % url)
+            raise ValidationError('Invalid SCM URL: %s' % url)
 
         if self.scheme == "git":
             match = re.search(r"^(?P<repository>.*/(?P<name>[^?]*))(\?#(?P<commit>.*))?", url)
@@ -89,7 +91,7 @@ class SCM(object):
                 self.name = self.name[:-4]
             self.commit = match.group("commit")
         else:
-            raise RuntimeError("Unhandled SCM scheme: %s" % self.scheme)
+            raise ValidationError("Unhandled SCM scheme: %s" % self.scheme)
 
     @staticmethod
     @rida.utils.retry(wait_on=RuntimeError)

rida/views.py

@@ -40,7 +40,8 @@ import tempfile
 from rida import app, conf, db, log
 from rida import models
 from rida.utils import pagination_metadata, filter_module_builds
-from errors import ValidationError
+from errors import (ValidationError, Unauthorized, UnprocessableEntity,
+                    Conflict, NotFound)
 
 
 @app.route("/rida/module-builds/", methods=["POST"])
@@ -48,15 +49,16 @@ def submit_build():
     """Handles new module build submissions."""
     username = rida.auth.is_packager(conf.pkgdb_api_url)
     if not username:
-        return "You must use your Fedora certificate when submitting a new build", 403
+        raise Unauthorized("You must use your Fedora certificate "
+                           "when submitting a new build")
 
     try:
         r = json.loads(request.get_data().decode("utf-8"))
     except:
-        return "Invalid JSON submitted", 400
+        raise ValidationError('Invalid JSON submitted')
 
     if "scmurl" not in r:
-        return "Missing scmurl", 400
+        raise ValidationError('Missing scmurl')
 
     url = r["scmurl"]
     urlallowed = False
@@ -68,7 +70,7 @@ def submit_build():
             break
 
     if not urlallowed:
-        return "The submitted scmurl isn't allowed", 403
+        raise Unauthorized('The submitted scmurl isn\'t allowed')
 
     yaml = str()
     td = None
@@ -80,14 +82,6 @@ def submit_build():
 
         with open(cofn, "r") as mmdfile:
             yaml = mmdfile.read()
-    except Exception as e:
-        if "is not in the list of allowed SCMs" in str(e):
-            rc = 403
-        elif "Invalid SCM URL" in str(e):
-            rc = 400
-        else:
-            rc = 500
-        return str(e), rc
     finally:
         try:
             if td is not None:
@@ -101,10 +95,10 @@ def submit_build():
     try:
         mmd.loads(yaml)
     except:
-        return "Invalid modulemd", 422
+        raise UnprocessableEntity('Invalid modulemd')
 
     if models.ModuleBuild.query.filter_by(name=mmd.name, version=mmd.version, release=mmd.release).first():
-        return "Module already exists", 409
+        raise Conflict('Module already exists')
 
     module = models.ModuleBuild.create(
         db.session,
@@ -117,33 +111,34 @@ def submit_build():
         username=username
     )
 
-    def failure(message, code):
-        # TODO, we should make some note of why it failed in the db..
-        log.exception(message)
-        module.transition(conf, models.BUILD_STATES["failed"])
-        db.session.add(module)
-        db.session.commit()
-        return message, code
-
     for pkgname, pkg in mmd.components.rpms.packages.items():
-        if pkg.get("repository") and not conf.rpms_allow_repository:
+        try:
-            return failure("Custom component repositories aren't allowed", 403)
+            if pkg.get("repository") and not conf.rpms_allow_repository:
-        if pkg.get("cache") and not conf.rpms_allow_cache:
+                raise Unauthorized(
-            return failure("Custom component caches aren't allowed", 403)
+                    "Custom component repositories aren't allowed")
-        if not pkg.get("repository"):
+            if pkg.get("cache") and not conf.rpms_allow_cache:
-            pkg["repository"] = conf.rpms_default_repository + pkgname
+                raise Unauthorized("Custom component caches aren't allowed")
-        if not pkg.get("cache"):
+            if not pkg.get("repository"):
-            pkg["cache"] = conf.rpms_default_cache + pkgname
+                pkg["repository"] = conf.rpms_default_repository + pkgname
-        if not pkg.get("commit"):
+            if not pkg.get("cache"):
-            try:
+                pkg["cache"] = conf.rpms_default_cache + pkgname
-                pkg["commit"] = rida.scm.SCM(pkg["repository"]).get_latest()
+            if not pkg.get("commit"):
-            except Exception as e:
+                try:
-                return failure("Failed to get the latest commit: %s" % pkgname, 422)
+                    pkg["commit"] = rida.scm.SCM(
+                        pkg["repository"]).get_latest()
+                except Exception as e:
+                    raise UnprocessableEntity(
+                        "Failed to get the latest commit: %s" % pkgname)
+        except Exception:
+            module.transition(conf, models.BUILD_STATES["failed"])
+            db.session.add(module)
+            db.session.commit()
+            raise
 
         full_url = pkg["repository"] + "?#" + pkg["commit"]
 
         if not rida.scm.SCM(full_url).is_available():
-            return failure("Cannot checkout %s" % pkgname, 422)
+            raise UnprocessableEntity("Cannot checkout %s" % pkgname)
 
         build = models.ComponentBuild(
             module_id=module.id,
@@ -165,10 +160,7 @@ def submit_build():
 @app.route("/rida/module-builds/", methods=["GET"])
 def query_builds():
     """Lists all tracked module builds."""
-    try:
+    p_query = filter_module_builds(request)
-        p_query = filter_module_builds(request)
-    except ValidationError as e:
-        return e.message, 400
 
     json_data = {
         'meta': pagination_metadata(p_query)
@@ -192,4 +184,4 @@ def query_build(id):
     if module:
         return jsonify(module.api_json()), 200
     else:
-        return "No such module found.", 404
+        raise NotFound('No such module found.')