From 1c0715662a930b027b225f8b1a19fb002f25af47 Mon Sep 17 00:00:00 2001
From: Chenxiong Qi <cqi@redhat.com>
Date: Sun, 19 Jan 2020 10:30:03 +0800
Subject: [PATCH] Cleanup module_build_service/__init__.py

Most of the code are moved to dedicated subpackages, but some others
can't due to the cycle dependencies.

Signed-off-by: Chenxiong Qi <cqi@redhat.com>
---
 module_build_service/__init__.py              | 100 ++----------------
 .../builder/KojiContentGenerator.py           |   3 +-
 .../builder/KojiModuleBuilder.py              |   3 +-
 .../builder/MockModuleBuilder.py              |   4 +-
 module_build_service/builder/base.py          |   3 +-
 module_build_service/builder/utils.py         |   3 +-
 module_build_service/common/__init__.py       |  12 +++
 module_build_service/common/config.py         |   3 +
 module_build_service/common/errors.py         |   8 --
 module_build_service/common/koji.py           |   2 +-
 module_build_service/common/messaging.py      |   2 +-
 module_build_service/common/models.py         |   3 +-
 module_build_service/common/modulemd.py       |   8 ++
 module_build_service/common/resolve.py        |   2 +-
 module_build_service/common/retry.py          |   2 +-
 module_build_service/common/scm.py            |   2 +-
 module_build_service/common/submit.py         |   2 +-
 module_build_service/common/utils.py          |   3 +-
 module_build_service/manage.py                |  18 +++-
 .../526fb7d445f7_module_buildrequires.py      |   3 +-
 .../6d503efcd2b8_virtual_streams_table.py     |   3 +-
 .../708ac8950f55_set_from_mmd_context.py      |   2 +-
 .../versions/9ca1c166f426_contexts.py         |   2 +-
 .../migrations/versions/a87264eeb49f_.py      |   2 +-
 .../caeae7a4f537_ref_build_context.py         |   2 +-
 module_build_service/resolver/DBResolver.py   |   3 +-
 module_build_service/resolver/KojiResolver.py |   3 +-
 module_build_service/resolver/MBSResolver.py  |   2 +-
 module_build_service/resolver/base.py         |   5 +-
 module_build_service/scheduler/__init__.py    |  15 +++
 module_build_service/scheduler/batches.py     |   3 +-
 module_build_service/scheduler/consumer.py    |   3 +-
 module_build_service/scheduler/db_session.py  |   7 +-
 .../scheduler/default_modules.py              |   4 +-
 module_build_service/scheduler/events.py      |   2 +-
 module_build_service/scheduler/greenwave.py   |   2 +-
 .../scheduler/handlers/components.py          |   5 +-
 .../scheduler/handlers/greenwave.py           |   4 +-
 .../scheduler/handlers/modules.py             |   4 +-
 .../scheduler/handlers/repos.py               |   5 +-
 .../scheduler/handlers/tags.py                |   5 +-
 module_build_service/scheduler/parser.py      |   2 +-
 module_build_service/scheduler/producer.py    |   4 +-
 module_build_service/scheduler/reuse.py       |   3 +-
 module_build_service/scheduler/route.py       |   3 +-
 module_build_service/scheduler/submit.py      |   6 +-
 module_build_service/scheduler/ursine.py      |   2 +-
 module_build_service/web/auth.py              |   3 +-
 module_build_service/web/backports.py         |   6 +-
 module_build_service/web/mmd_resolver.py      |  11 +-
 module_build_service/web/mse.py               |   4 +-
 module_build_service/web/submit.py            |   4 +-
 module_build_service/web/utils.py             |   4 +-
 module_build_service/web/views.py             |  56 +++++++++-
 tests/__init__.py                             |   3 +-
 tests/conftest.py                             |   4 +-
 tests/test_build/test_build.py                |   4 +-
 tests/test_builder/test_builder_utils.py      |   2 +-
 tests/test_builder/test_content_generator.py  |   4 +-
 tests/test_builder/test_koji.py               |   3 +-
 tests/test_builder/test_mock.py               |  10 +-
 tests/test_common/test_config.py              |   2 +-
 tests/test_common/test_logger.py              |   3 +-
 tests/test_common/test_models/test_models.py  |   2 +-
 tests/test_common/test_monitor.py             |   4 +-
 tests/test_common/test_resolve.py             |   2 +-
 tests/test_resolver/test_db.py                |   3 +-
 tests/test_resolver/test_koji.py              |   2 +-
 tests/test_resolver/test_local.py             |   2 +-
 tests/test_resolver/test_mbs.py               |   3 +-
 tests/test_scheduler/test_batches.py          |   2 +-
 .../test_scheduler/test_celery_route_task.py  |   3 +-
 tests/test_scheduler/test_db_session.py       |   2 +-
 tests/test_scheduler/test_default_modules.py  |   2 +-
 .../test_scheduler/test_greenwave_handler.py  |   2 +-
 tests/test_scheduler/test_module_init.py      |   2 +-
 tests/test_scheduler/test_module_wait.py      |   3 +-
 tests/test_scheduler/test_poller.py           |   2 +-
 tests/test_scheduler/test_reuse.py            |   2 +-
 tests/test_scheduler/test_submit.py           |   4 +-
 tests/test_scheduler/test_ursine.py           |   2 +-
 81 files changed, 235 insertions(+), 221 deletions(-)
 create mode 100644 module_build_service/common/modulemd.py

diff --git a/module_build_service/__init__.py b/module_build_service/__init__.py
index 3728231f..292ffa67 100644
--- a/module_build_service/__init__.py
+++ b/module_build_service/__init__.py
@@ -19,22 +19,14 @@ for a number of tasks:
 """
 
 from __future__ import absolute_import
-from logging import getLogger
 
-from celery import Celery
-import gi  # noqa
-gi.require_version("Modulemd", "2.0")  # noqa
-from gi.repository import Modulemd  # noqa
+import pkg_resources
+
 from flask import Flask, has_app_context, url_for
 from flask_sqlalchemy import SQLAlchemy
-import pkg_resources
 from sqlalchemy.pool import StaticPool
 
-from module_build_service.common.config import init_config
-from module_build_service.common.errors import (
-    ValidationError, Unauthorized, UnprocessableEntity, Conflict, NotFound,
-    Forbidden, json_error)
-from module_build_service.common.logger import init_logging, ModuleBuildLogs, level_flags, MBSLogger
+from module_build_service.common.config import config_section
 from module_build_service.web.proxy import ReverseProxy
 
 try:
@@ -43,22 +35,10 @@ except pkg_resources.DistributionNotFound:
     version = "unknown"
 api_version = 2
 
-conf, config_section = init_config()
 app = Flask(__name__)
 app.wsgi_app = ReverseProxy(app.wsgi_app)
 app.config.from_object(config_section)
 
-celery_app = Celery("module-build-service")
-# Convert config names specific for Celery like this:
-# celery_broker_url -> broker_url
-celery_configs = {
-    name[7:]: getattr(conf, name)
-    for name in dir(conf) if name.startswith("celery_")
-}
-# Only allow a single process so that tasks are always serial per worker
-celery_configs["worker_concurrency"] = 1
-celery_app.conf.update(**celery_configs)
-
 
 class MBSSQLAlchemy(SQLAlchemy):
     """
@@ -83,73 +63,6 @@ class MBSSQLAlchemy(SQLAlchemy):
 db = MBSSQLAlchemy(app)
 
 
-def create_app(debug=False, verbose=False, quiet=False):
-    # logging (intended for flask-script, see manage.py)
-    log = getLogger(__name__)
-    if debug:
-        log.setLevel(level_flags["debug"])
-    elif verbose:
-        log.setLevel(level_flags["verbose"])
-    elif quiet:
-        log.setLevel(level_flags["quiet"])
-
-    return app
-
-
-def load_views():
-    from module_build_service.web import views
-
-    assert views
-
-
-@app.errorhandler(ValidationError)
-def validationerror_error(e):
-    """Flask error handler for ValidationError exceptions"""
-    return json_error(400, "Bad Request", str(e))
-
-
-@app.errorhandler(Unauthorized)
-def unauthorized_error(e):
-    """Flask error handler for NotAuthorized exceptions"""
-    return json_error(401, "Unauthorized", str(e))
-
-
-@app.errorhandler(Forbidden)
-def forbidden_error(e):
-    """Flask error handler for Forbidden exceptions"""
-    return json_error(403, "Forbidden", str(e))
-
-
-@app.errorhandler(RuntimeError)
-def runtimeerror_error(e):
-    """Flask error handler for RuntimeError exceptions"""
-    log.exception("RuntimeError exception raised")
-    return json_error(500, "Internal Server Error", str(e))
-
-
-@app.errorhandler(UnprocessableEntity)
-def unprocessableentity_error(e):
-    """Flask error handler for UnprocessableEntity exceptions"""
-    return json_error(422, "Unprocessable Entity", str(e))
-
-
-@app.errorhandler(Conflict)
-def conflict_error(e):
-    """Flask error handler for Conflict exceptions"""
-    return json_error(409, "Conflict", str(e))
-
-
-@app.errorhandler(NotFound)
-def notfound_error(e):
-    """Flask error handler for Conflict exceptions"""
-    return json_error(404, "Not Found", str(e))
-
-
-init_logging(conf)
-log = MBSLogger()
-build_logs = ModuleBuildLogs(conf.build_logs_dir, conf.build_logs_name_format, conf.log_level)
-
-
 def get_url_for(*args, **kwargs):
     """
     flask.url_for wrapper which creates the app_context on-the-fly.
@@ -161,6 +74,7 @@ def get_url_for(*args, **kwargs):
     # system as the web views.
     app.config["SERVER_NAME"] = "localhost"
     with app.app_context():
+        from module_build_service.common import log
         log.debug(
             "WARNING: get_url_for() has been called without the Flask "
             "app_context. That can lead to SQLAlchemy errors caused by "
@@ -169,4 +83,10 @@ def get_url_for(*args, **kwargs):
         return url_for(*args, **kwargs)
 
 
+def load_views():
+    from module_build_service.web import views
+
+    assert views
+
+
 load_views()
diff --git a/module_build_service/builder/KojiContentGenerator.py b/module_build_service/builder/KojiContentGenerator.py
index 321646ed..d7f65dd7 100644
--- a/module_build_service/builder/KojiContentGenerator.py
+++ b/module_build_service/builder/KojiContentGenerator.py
@@ -21,7 +21,8 @@ import koji
 import pungi.arch
 from six import text_type
 
-from module_build_service import conf, log, build_logs, Modulemd
+from module_build_service.common.modulemd import Modulemd
+from module_build_service.common import conf, log, build_logs
 from module_build_service.common.koji import get_session, koji_retrying_multicall_map
 from module_build_service.common.scm import SCM
 from module_build_service.common.utils import load_mmd, mmd_to_str, to_text_type
diff --git a/module_build_service/builder/KojiModuleBuilder.py b/module_build_service/builder/KojiModuleBuilder.py
index 3a4858d9..9c89441e 100644
--- a/module_build_service/builder/KojiModuleBuilder.py
+++ b/module_build_service/builder/KojiModuleBuilder.py
@@ -22,11 +22,10 @@ import koji
 import kobo.rpmlib
 from OpenSSL.SSL import SysCallError
 
-from module_build_service import log, conf
 from module_build_service.builder import GenericBuilder
 from module_build_service.builder.KojiContentGenerator import KojiContentGenerator
 from module_build_service.builder.utils import execute_cmd, get_rpm_release, validate_koji_tag
-from module_build_service.common import models
+from module_build_service.common import log, conf, models
 from module_build_service.common.koji import (
     get_session, koji_multicall_map, koji_retrying_multicall_map,
 )
diff --git a/module_build_service/builder/MockModuleBuilder.py b/module_build_service/builder/MockModuleBuilder.py
index 4a7810c7..70e3e955 100644
--- a/module_build_service/builder/MockModuleBuilder.py
+++ b/module_build_service/builder/MockModuleBuilder.py
@@ -13,7 +13,6 @@ import koji
 import kobo.rpmlib
 import platform
 
-from module_build_service import conf, log, Modulemd
 from module_build_service.builder import GenericBuilder
 from module_build_service.builder.KojiModuleBuilder import KojiModuleBuilder
 from module_build_service.builder.utils import (
@@ -23,8 +22,9 @@ from module_build_service.builder.utils import (
     get_koji_config,
     validate_koji_tag,
 )
-from module_build_service.common import models
+from module_build_service.common import conf, log, models
 from module_build_service.common.koji import get_session
+from module_build_service.common.modulemd import Modulemd
 from module_build_service.common.utils import import_mmd, load_mmd_file, mmd_to_str
 from module_build_service.scheduler import events
 from module_build_service.scheduler.db_session import db_session
diff --git a/module_build_service/builder/base.py b/module_build_service/builder/base.py
index 13443f5d..d122823b 100644
--- a/module_build_service/builder/base.py
+++ b/module_build_service/builder/base.py
@@ -9,8 +9,7 @@ import dogpile.cache
 from requests.exceptions import ConnectionError
 import six
 
-from module_build_service import conf, log
-from module_build_service.common import models
+from module_build_service.common import conf, log, models
 from module_build_service.common.models import BUILD_STATES
 from module_build_service.common.retry import retry
 from module_build_service.resolver import GenericResolver
diff --git a/module_build_service/builder/utils.py b/module_build_service/builder/utils.py
index d987f3fc..fe5d1003 100644
--- a/module_build_service/builder/utils.py
+++ b/module_build_service/builder/utils.py
@@ -13,8 +13,7 @@ import subprocess
 import munch
 import requests
 
-from module_build_service import conf, log
-from module_build_service.common import models
+from module_build_service.common import conf, log, models
 from module_build_service.common.errors import ValidationError, ProgrammingError
 
 
diff --git a/module_build_service/common/__init__.py b/module_build_service/common/__init__.py
index e69de29b..b0612ea1 100644
--- a/module_build_service/common/__init__.py
+++ b/module_build_service/common/__init__.py
@@ -0,0 +1,12 @@
+# -*- coding: utf-8 -*-
+# SPDX-License-Identifier: MIT
+
+from module_build_service.common.config import conf
+from module_build_service.common import logger
+
+__all__ = ('conf', 'log', 'build_logs')
+
+logger.init_logging(conf)
+log = logger.MBSLogger()
+build_logs = logger.ModuleBuildLogs(
+    conf.build_logs_dir, conf.build_logs_name_format, conf.log_level)
diff --git a/module_build_service/common/config.py b/module_build_service/common/config.py
index a77c79c8..77c32dd6 100644
--- a/module_build_service/common/config.py
+++ b/module_build_service/common/config.py
@@ -989,3 +989,6 @@ class Config(object):
         if i < 1:
             raise ValueError("NUM_THREADS_FOR_BUILD_SUBMISSIONS must be >= 1")
         self._num_threads_for_build_submissions = i
+
+
+conf, config_section = init_config()
diff --git a/module_build_service/common/errors.py b/module_build_service/common/errors.py
index a49ffe69..7c370a88 100644
--- a/module_build_service/common/errors.py
+++ b/module_build_service/common/errors.py
@@ -4,8 +4,6 @@
 
 from __future__ import absolute_import
 
-from flask import jsonify
-
 
 class ValidationError(ValueError):
     pass
@@ -43,11 +41,5 @@ class GreenwaveError(RuntimeError):
     pass
 
 
-def json_error(status, error, message):
-    response = jsonify({"status": status, "error": error, "message": message})
-    response.status_code = status
-    return response
-
-
 class IgnoreMessage(Exception):
     """Raise if message received from message bus should be ignored"""
diff --git a/module_build_service/common/koji.py b/module_build_service/common/koji.py
index cf779d93..d7f6793b 100644
--- a/module_build_service/common/koji.py
+++ b/module_build_service/common/koji.py
@@ -7,7 +7,7 @@ import koji
 import munch
 import six.moves.xmlrpc_client as xmlrpclib
 
-from module_build_service import log
+from module_build_service.common import log
 from module_build_service.common.retry import retry
 from module_build_service.common.errors import ProgrammingError
 
diff --git a/module_build_service/common/messaging.py b/module_build_service/common/messaging.py
index e5f22b5c..82c71ff4 100644
--- a/module_build_service/common/messaging.py
+++ b/module_build_service/common/messaging.py
@@ -7,7 +7,7 @@ from __future__ import absolute_import
 import pkg_resources
 import six.moves.queue
 
-from module_build_service import conf, log
+from module_build_service.common import conf, log
 from module_build_service.scheduler.parser import FedmsgMessageParser
 
 # A queue containing message body that should be sent after
diff --git a/module_build_service/common/models.py b/module_build_service/common/models.py
index 0894cc32..5a733fa1 100644
--- a/module_build_service/common/models.py
+++ b/module_build_service/common/models.py
@@ -19,7 +19,8 @@ from sqlalchemy.orm import validates, load_only
 from sqlalchemy.schema import Index
 
 
-from module_build_service import db, log, get_url_for, conf
+from module_build_service import db, get_url_for
+from module_build_service.common import conf, log
 from module_build_service.common.errors import UnprocessableEntity
 from module_build_service.common.messaging import module_build_state_change_out_queue
 from module_build_service.common.messaging import notify_on_module_state_change
diff --git a/module_build_service/common/modulemd.py b/module_build_service/common/modulemd.py
new file mode 100644
index 00000000..26059234
--- /dev/null
+++ b/module_build_service/common/modulemd.py
@@ -0,0 +1,8 @@
+# -*- coding: utf-8 -*-
+# SPDX-License-Identifier: MIT
+
+import gi
+gi.require_version("Modulemd", "2.0")
+from gi.repository import Modulemd  # noqa
+
+__all__ = ['Modulemd']
diff --git a/module_build_service/common/resolve.py b/module_build_service/common/resolve.py
index 363b31af..81c1b0c5 100644
--- a/module_build_service/common/resolve.py
+++ b/module_build_service/common/resolve.py
@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: MIT
 from __future__ import absolute_import
 
-from module_build_service import conf
+from module_build_service.common.config import conf
 from module_build_service.common.errors import StreamAmbigous
 from module_build_service.resolver import GenericResolver
 
diff --git a/module_build_service/common/retry.py b/module_build_service/common/retry.py
index 9e1f8f73..a8728e13 100644
--- a/module_build_service/common/retry.py
+++ b/module_build_service/common/retry.py
@@ -4,7 +4,7 @@ from __future__ import absolute_import
 import functools
 import time
 
-from module_build_service import conf, log
+from module_build_service.common import conf, log
 
 
 def retry(timeout=conf.net_timeout, interval=conf.net_retry_interval, wait_on=Exception):
diff --git a/module_build_service/common/scm.py b/module_build_service/common/scm.py
index f0614fcf..c8b1d79a 100644
--- a/module_build_service/common/scm.py
+++ b/module_build_service/common/scm.py
@@ -10,7 +10,7 @@ import re
 import shutil
 import tempfile
 
-from module_build_service import log, conf
+from module_build_service.common import log, conf
 from module_build_service.common.errors import (
     Forbidden,
     ValidationError,
diff --git a/module_build_service/common/submit.py b/module_build_service/common/submit.py
index a182637d..b0b78494 100644
--- a/module_build_service/common/submit.py
+++ b/module_build_service/common/submit.py
@@ -7,7 +7,7 @@ import tempfile
 import requests
 
 import module_build_service.common.scm
-from module_build_service import conf, log
+from module_build_service.common import conf, log
 from module_build_service.common.errors import ValidationError
 from module_build_service.common.utils import load_mmd_file
 
diff --git a/module_build_service/common/utils.py b/module_build_service/common/utils.py
index 1fea79ec..b80b829d 100644
--- a/module_build_service/common/utils.py
+++ b/module_build_service/common/utils.py
@@ -8,8 +8,9 @@ import os
 from gi.repository.GLib import Error as ModuleMDError
 from six import string_types, text_type
 
-from module_build_service import conf, log, Modulemd
+from module_build_service.common import conf, log
 from module_build_service.common.errors import UnprocessableEntity
+from module_build_service.common.modulemd import Modulemd
 
 
 def to_text_type(s):
diff --git a/module_build_service/manage.py b/module_build_service/manage.py
index d4d5425d..925b5031 100755
--- a/module_build_service/manage.py
+++ b/module_build_service/manage.py
@@ -11,12 +11,13 @@ import flask_migrate
 from flask_script import Manager, prompt_bool
 from werkzeug.datastructures import FileStorage
 
-from module_build_service import app, conf, create_app, db
+from module_build_service import app, db
 from module_build_service.builder.MockModuleBuilder import (
     import_builds_from_local_dnf_repos, load_local_builds
 )
-from module_build_service.common import models
+from module_build_service.common import conf, models
 from module_build_service.common.errors import StreamAmbigous
+from module_build_service.common.logger import level_flags
 from module_build_service.common.utils import load_mmd_file, import_mmd
 import module_build_service.scheduler.consumer
 from module_build_service.scheduler.db_session import db_session
@@ -24,6 +25,19 @@ import module_build_service.scheduler.local
 from module_build_service.web.submit import submit_module_build_from_yaml
 
 
+def create_app(debug=False, verbose=False, quiet=False):
+    # logging (intended for flask-script, see manage.py)
+    log = logging.getLogger(__name__)
+    if debug:
+        log.setLevel(level_flags["debug"])
+    elif verbose:
+        log.setLevel(level_flags["verbose"])
+    elif quiet:
+        log.setLevel(level_flags["quiet"])
+
+    return app
+
+
 manager = Manager(create_app)
 help_args = ("-?", "--help")
 manager.help_args = help_args
diff --git a/module_build_service/migrations/versions/526fb7d445f7_module_buildrequires.py b/module_build_service/migrations/versions/526fb7d445f7_module_buildrequires.py
index 2d24dc3c..7d02594e 100644
--- a/module_build_service/migrations/versions/526fb7d445f7_module_buildrequires.py
+++ b/module_build_service/migrations/versions/526fb7d445f7_module_buildrequires.py
@@ -14,8 +14,9 @@ from alembic import op
 import sqlalchemy as sa
 
 # Data migration imports
-from module_build_service import Modulemd, conf
+from module_build_service.common import conf
 from module_build_service.common.models import ModuleBuild
+from module_build_service.common.modulemd import Modulemd
 
 # Data migration tables
 mb = sa.Table(
diff --git a/module_build_service/migrations/versions/6d503efcd2b8_virtual_streams_table.py b/module_build_service/migrations/versions/6d503efcd2b8_virtual_streams_table.py
index f5763b6f..c041ff53 100644
--- a/module_build_service/migrations/versions/6d503efcd2b8_virtual_streams_table.py
+++ b/module_build_service/migrations/versions/6d503efcd2b8_virtual_streams_table.py
@@ -16,7 +16,8 @@ from sqlalchemy.orm import relationship
 from sqlalchemy.ext.declarative import declarative_base
 
 # Data migration imports
-from module_build_service import Modulemd, conf
+from module_build_service.common import conf
+from module_build_service.common.modulemd import Modulemd
 
 
 Base = declarative_base()
diff --git a/module_build_service/migrations/versions/708ac8950f55_set_from_mmd_context.py b/module_build_service/migrations/versions/708ac8950f55_set_from_mmd_context.py
index f7923420..0d80965b 100644
--- a/module_build_service/migrations/versions/708ac8950f55_set_from_mmd_context.py
+++ b/module_build_service/migrations/versions/708ac8950f55_set_from_mmd_context.py
@@ -14,8 +14,8 @@ from alembic import op
 import sqlalchemy as sa
 
 # Data migration imports
-from module_build_service import Modulemd
 import hashlib
+from module_build_service.common.modulemd import Modulemd
 
 
 modulebuild = sa.Table(
diff --git a/module_build_service/migrations/versions/9ca1c166f426_contexts.py b/module_build_service/migrations/versions/9ca1c166f426_contexts.py
index 81d81208..7d303480 100644
--- a/module_build_service/migrations/versions/9ca1c166f426_contexts.py
+++ b/module_build_service/migrations/versions/9ca1c166f426_contexts.py
@@ -14,7 +14,7 @@ from alembic import op
 import sqlalchemy as sa
 
 # Data migration imports
-from module_build_service import Modulemd
+from module_build_service.common.modulemd import Modulemd
 import hashlib
 import json
 from collections import OrderedDict
diff --git a/module_build_service/migrations/versions/a87264eeb49f_.py b/module_build_service/migrations/versions/a87264eeb49f_.py
index aae8a9bc..78f91fd5 100644
--- a/module_build_service/migrations/versions/a87264eeb49f_.py
+++ b/module_build_service/migrations/versions/a87264eeb49f_.py
@@ -12,8 +12,8 @@ down_revision = "1817e62719f9"
 
 from alembic import op
 import sqlalchemy as sa
-from module_build_service import Modulemd
 from module_build_service.common.models import ModuleBuild
+from module_build_service.common.modulemd import Modulemd
 
 
 modulebuild = sa.Table(
diff --git a/module_build_service/migrations/versions/caeae7a4f537_ref_build_context.py b/module_build_service/migrations/versions/caeae7a4f537_ref_build_context.py
index 2f047fb7..ffc2e25e 100644
--- a/module_build_service/migrations/versions/caeae7a4f537_ref_build_context.py
+++ b/module_build_service/migrations/versions/caeae7a4f537_ref_build_context.py
@@ -14,7 +14,7 @@ from alembic import op
 import sqlalchemy as sa
 
 # Data migration imports
-from module_build_service import Modulemd
+from module_build_service.common.modulemd import Modulemd
 import hashlib
 import json
 from collections import OrderedDict
diff --git a/module_build_service/resolver/DBResolver.py b/module_build_service/resolver/DBResolver.py
index b1a3acd4..a0aa433d 100644
--- a/module_build_service/resolver/DBResolver.py
+++ b/module_build_service/resolver/DBResolver.py
@@ -5,8 +5,7 @@ from __future__ import absolute_import
 import sqlalchemy
 from sqlalchemy.orm import aliased
 
-from module_build_service import log
-from module_build_service.common import models
+from module_build_service.common import log, models
 from module_build_service.common.errors import UnprocessableEntity
 from module_build_service.common.utils import load_mmd
 from module_build_service.resolver.base import GenericResolver
diff --git a/module_build_service/resolver/KojiResolver.py b/module_build_service/resolver/KojiResolver.py
index 919e319d..ebea974f 100644
--- a/module_build_service/resolver/KojiResolver.py
+++ b/module_build_service/resolver/KojiResolver.py
@@ -3,8 +3,7 @@
 from __future__ import absolute_import
 from itertools import groupby
 
-from module_build_service import conf, log
-from module_build_service.common import models
+from module_build_service.common import conf, log, models
 from module_build_service.common.koji import get_session, koji_multicall_map
 from module_build_service.resolver.DBResolver import DBResolver
 
diff --git a/module_build_service/resolver/MBSResolver.py b/module_build_service/resolver/MBSResolver.py
index 98bbe7cc..3cd8dce9 100644
--- a/module_build_service/resolver/MBSResolver.py
+++ b/module_build_service/resolver/MBSResolver.py
@@ -7,8 +7,8 @@ import logging
 
 import kobo.rpmlib
 
-from module_build_service import conf
 from module_build_service.common import models
+from module_build_service.common.config import conf
 from module_build_service.common.errors import UnprocessableEntity
 from module_build_service.common.request_utils import requests_session
 from module_build_service.common.utils import load_mmd, import_mmd
diff --git a/module_build_service/resolver/base.py b/module_build_service/resolver/base.py
index aeb40a6b..776ff78d 100644
--- a/module_build_service/resolver/base.py
+++ b/module_build_service/resolver/base.py
@@ -7,8 +7,7 @@ from __future__ import absolute_import
 from abc import ABCMeta, abstractmethod
 import six
 
-from module_build_service import conf
-import module_build_service.common.config as cfg
+from module_build_service.common.config import conf, SUPPORTED_RESOLVERS
 
 
 class GenericResolver(six.with_metaclass(ABCMeta)):
@@ -16,7 +15,7 @@ class GenericResolver(six.with_metaclass(ABCMeta)):
     External Api for resolvers
     """
 
-    _resolvers = cfg.SUPPORTED_RESOLVERS
+    _resolvers = SUPPORTED_RESOLVERS
 
     # Resolver name. Each subclass of GenericResolver must set its own name.
     backend = "generic"
diff --git a/module_build_service/scheduler/__init__.py b/module_build_service/scheduler/__init__.py
index 01d69e8d..ccb59420 100644
--- a/module_build_service/scheduler/__init__.py
+++ b/module_build_service/scheduler/__init__.py
@@ -1,3 +1,18 @@
 # -*- coding: utf-8 -*-
 # SPDX-License-Identifier: MIT
 """ This is a sub-module for backend/scheduler functionality. """
+
+from celery import Celery
+
+from module_build_service.common.config import conf
+
+celery_app = Celery("module-build-service")
+# Convert config names specific for Celery like this:
+# celery_broker_url -> broker_url
+celery_configs = {
+    name[7:]: getattr(conf, name)
+    for name in dir(conf) if name.startswith("celery_")
+}
+# Only allow a single process so that tasks are always serial per worker
+celery_configs["worker_concurrency"] = 1
+celery_app.conf.update(**celery_configs)
diff --git a/module_build_service/scheduler/batches.py b/module_build_service/scheduler/batches.py
index 1994b4ab..ef8f4e96 100644
--- a/module_build_service/scheduler/batches.py
+++ b/module_build_service/scheduler/batches.py
@@ -4,8 +4,7 @@ from __future__ import absolute_import
 import concurrent.futures
 import threading
 
-from module_build_service import conf, log
-from module_build_service.common import models
+from module_build_service.common import conf, log, models
 from module_build_service.scheduler import events
 from module_build_service.scheduler.db_session import db_session
 from module_build_service.scheduler.reuse import get_reusable_components, reuse_component
diff --git a/module_build_service/scheduler/consumer.py b/module_build_service/scheduler/consumer.py
index 7ba2ad8b..c242666f 100644
--- a/module_build_service/scheduler/consumer.py
+++ b/module_build_service/scheduler/consumer.py
@@ -20,8 +20,7 @@ import fedmsg.consumers
 import moksha.hub
 import sqlalchemy.exc
 
-from module_build_service import log, conf
-from module_build_service.common import models
+from module_build_service.common import log, conf, models
 from module_build_service.common.errors import IgnoreMessage
 import module_build_service.common.messaging
 from module_build_service.common.messaging import default_messaging_backend
diff --git a/module_build_service/scheduler/db_session.py b/module_build_service/scheduler/db_session.py
index 1e2890f6..580aed44 100644
--- a/module_build_service/scheduler/db_session.py
+++ b/module_build_service/scheduler/db_session.py
@@ -6,9 +6,10 @@ import sqlalchemy.event
 from sqlalchemy.pool import NullPool
 from sqlalchemy.orm import scoped_session, sessionmaker
 
-from module_build_service import conf
-from module_build_service.common.models import send_message_after_module_build_state_change
-from module_build_service.common.models import session_before_commit_handlers
+from module_build_service.common.config import conf
+from module_build_service.common.models import (
+    session_before_commit_handlers, send_message_after_module_build_state_change
+)
 
 __all__ = ("db_session",)
 
diff --git a/module_build_service/scheduler/default_modules.py b/module_build_service/scheduler/default_modules.py
index 62877454..40612012 100644
--- a/module_build_service/scheduler/default_modules.py
+++ b/module_build_service/scheduler/default_modules.py
@@ -11,10 +11,10 @@ import kobo.rpmlib
 import koji
 import six.moves.xmlrpc_client as xmlrpclib
 
-from module_build_service import conf, log, Modulemd
-from module_build_service.common import models, scm
+from module_build_service.common import conf, log, models, scm
 from module_build_service.common.errors import UnprocessableEntity
 from module_build_service.common.koji import get_session, koji_retrying_multicall_map
+from module_build_service.common.modulemd import Modulemd
 from module_build_service.common.resolve import (
     expand_single_mse_streams, get_compatible_base_module_mmds
 )
diff --git a/module_build_service/scheduler/events.py b/module_build_service/scheduler/events.py
index 4a176724..f0060b2c 100644
--- a/module_build_service/scheduler/events.py
+++ b/module_build_service/scheduler/events.py
@@ -17,7 +17,7 @@ from functools import wraps
 import sched
 import time
 
-from module_build_service import log
+from module_build_service.common import log
 
 
 KOJI_BUILD_CHANGE = "koji_build_change"
diff --git a/module_build_service/scheduler/greenwave.py b/module_build_service/scheduler/greenwave.py
index 1b00d5e4..9f1b770c 100644
--- a/module_build_service/scheduler/greenwave.py
+++ b/module_build_service/scheduler/greenwave.py
@@ -6,7 +6,7 @@ import json
 
 import requests
 
-from module_build_service import log, conf
+from module_build_service.common import log, conf
 from module_build_service.common.errors import GreenwaveError
 
 
diff --git a/module_build_service/scheduler/handlers/components.py b/module_build_service/scheduler/handlers/components.py
index 6dc2ce34..3a46c726 100644
--- a/module_build_service/scheduler/handlers/components.py
+++ b/module_build_service/scheduler/handlers/components.py
@@ -7,12 +7,11 @@ import logging
 
 import koji
 
-from module_build_service import celery_app, conf, log
 from module_build_service.builder import GenericBuilder
-from module_build_service.common import models
+from module_build_service.common import conf, log, models
 from module_build_service.common.koji import get_session
 from module_build_service.common.utils import mmd_to_str
-from module_build_service.scheduler import events
+from module_build_service.scheduler import celery_app, events
 from module_build_service.scheduler.batches import continue_batch_build
 from module_build_service.scheduler.db_session import db_session
 
diff --git a/module_build_service/scheduler/handlers/greenwave.py b/module_build_service/scheduler/handlers/greenwave.py
index 36bcf934..e8898c9b 100644
--- a/module_build_service/scheduler/handlers/greenwave.py
+++ b/module_build_service/scheduler/handlers/greenwave.py
@@ -2,11 +2,11 @@
 # SPDX-License-Identifier: MIT
 from __future__ import absolute_import
 
-from module_build_service import celery_app, conf, log
+from module_build_service.common import conf, log
 from module_build_service.common.koji import get_session
 from module_build_service.common.models import ModuleBuild, BUILD_STATES
 from module_build_service.scheduler.db_session import db_session
-from module_build_service.scheduler import events
+from module_build_service.scheduler import celery_app, events
 
 
 def get_corresponding_module_build(nvr):
diff --git a/module_build_service/scheduler/handlers/modules.py b/module_build_service/scheduler/handlers/modules.py
index 35e44db2..e8fc6253 100644
--- a/module_build_service/scheduler/handlers/modules.py
+++ b/module_build_service/scheduler/handlers/modules.py
@@ -11,11 +11,11 @@ import koji
 from requests.exceptions import ConnectionError
 import six.moves.xmlrpc_client as xmlrpclib
 
-from module_build_service import celery_app, conf, log, build_logs
 from module_build_service.builder import GenericBuilder
 from module_build_service.builder.KojiModuleBuilder import KojiModuleBuilder
 from module_build_service.builder.utils import get_rpm_release
 from module_build_service.common import models
+from module_build_service.common import build_logs, conf, log
 from module_build_service.common.errors import UnprocessableEntity, Forbidden, ValidationError
 from module_build_service.common.utils import mmd_to_str
 from module_build_service.common.retry import retry
@@ -25,7 +25,7 @@ from module_build_service.scheduler.submit import (
     record_filtered_rpms,
     record_module_build_arches
 )
-from module_build_service.scheduler import events
+from module_build_service.scheduler import celery_app, events
 from module_build_service.scheduler.db_session import db_session
 from module_build_service.scheduler.default_modules import (
     add_default_modules, handle_collisions_with_base_module_rpms)
diff --git a/module_build_service/scheduler/handlers/repos.py b/module_build_service/scheduler/handlers/repos.py
index 829b545b..1d190644 100644
--- a/module_build_service/scheduler/handlers/repos.py
+++ b/module_build_service/scheduler/handlers/repos.py
@@ -6,10 +6,9 @@ from __future__ import absolute_import
 from datetime import datetime
 import logging
 
-from module_build_service import celery_app, conf, log
 from module_build_service.builder import GenericBuilder
-from module_build_service.common import models
-from module_build_service.scheduler import events
+from module_build_service.common import conf, log, models
+from module_build_service.scheduler import celery_app, events
 from module_build_service.scheduler.batches import start_next_batch_build
 from module_build_service.scheduler.db_session import db_session
 
diff --git a/module_build_service/scheduler/handlers/tags.py b/module_build_service/scheduler/handlers/tags.py
index 2e3eff10..84e31fc5 100644
--- a/module_build_service/scheduler/handlers/tags.py
+++ b/module_build_service/scheduler/handlers/tags.py
@@ -7,10 +7,9 @@ import logging
 
 import koji
 
-from module_build_service import celery_app, conf, log
 from module_build_service.builder import GenericBuilder
-from module_build_service.common import models
-from module_build_service.scheduler import events
+from module_build_service.common import conf, log, models
+from module_build_service.scheduler import celery_app, events
 from module_build_service.scheduler.db_session import db_session
 
 logging.basicConfig(level=logging.DEBUG)
diff --git a/module_build_service/scheduler/parser.py b/module_build_service/scheduler/parser.py
index 17388675..77859b24 100644
--- a/module_build_service/scheduler/parser.py
+++ b/module_build_service/scheduler/parser.py
@@ -3,7 +3,7 @@
 from __future__ import absolute_import
 import re
 
-from module_build_service import log
+from module_build_service.common import log
 from module_build_service.common.errors import IgnoreMessage
 from module_build_service.scheduler import events
 
diff --git a/module_build_service/scheduler/producer.py b/module_build_service/scheduler/producer.py
index 72a18027..3e80db6d 100644
--- a/module_build_service/scheduler/producer.py
+++ b/module_build_service/scheduler/producer.py
@@ -8,12 +8,12 @@ import koji
 from sqlalchemy.orm import lazyload, load_only
 
 
-from module_build_service import celery_app, conf, log
+from module_build_service.common import conf, log, models
 from module_build_service.builder import GenericBuilder
-from module_build_service.common import models
 from module_build_service.common.koji import get_session
 import module_build_service.scheduler
 import module_build_service.scheduler.consumer
+from module_build_service.scheduler import celery_app
 from module_build_service.scheduler.consumer import ON_MODULE_CHANGE_HANDLERS
 from module_build_service.scheduler.batches import (
     at_concurrent_component_threshold,
diff --git a/module_build_service/scheduler/reuse.py b/module_build_service/scheduler/reuse.py
index 061f84bc..57305196 100644
--- a/module_build_service/scheduler/reuse.py
+++ b/module_build_service/scheduler/reuse.py
@@ -4,8 +4,7 @@ from __future__ import absolute_import
 
 import kobo.rpmlib
 
-from module_build_service import log, conf
-from module_build_service.common import models
+from module_build_service.common import log, conf, models
 from module_build_service.common.resolve import get_base_module_mmds
 from module_build_service.resolver import GenericResolver
 from module_build_service.scheduler import events
diff --git a/module_build_service/scheduler/route.py b/module_build_service/scheduler/route.py
index 5838a3ec..c74c78c6 100644
--- a/module_build_service/scheduler/route.py
+++ b/module_build_service/scheduler/route.py
@@ -5,8 +5,7 @@
 from __future__ import absolute_import
 import inspect
 
-from module_build_service import conf, log
-from module_build_service.common import models
+from module_build_service.common import conf, log, models
 from module_build_service.scheduler.db_session import db_session
 from module_build_service.scheduler.handlers.greenwave import get_corresponding_module_build
 
diff --git a/module_build_service/scheduler/submit.py b/module_build_service/scheduler/submit.py
index 7e954d8d..5f39ed73 100644
--- a/module_build_service/scheduler/submit.py
+++ b/module_build_service/scheduler/submit.py
@@ -8,10 +8,10 @@ import os
 
 import kobo.rpmlib
 
-from module_build_service import conf, log, Modulemd
-from module_build_service.common import models
-from module_build_service.common.errors import ValidationError, UnprocessableEntity, Forbidden
 import module_build_service.common.scm
+from module_build_service.common import conf, log, models
+from module_build_service.common.errors import ValidationError, UnprocessableEntity, Forbidden
+from module_build_service.common.modulemd import Modulemd
 from module_build_service.common.submit import fetch_mmd
 from module_build_service.common.utils import to_text_type
 from module_build_service.scheduler.db_session import db_session
diff --git a/module_build_service/scheduler/ursine.py b/module_build_service/scheduler/ursine.py
index c19fe157..cc890010 100644
--- a/module_build_service/scheduler/ursine.py
+++ b/module_build_service/scheduler/ursine.py
@@ -3,7 +3,7 @@
 from __future__ import absolute_import
 import re
 
-from module_build_service import conf, log
+from module_build_service.common import conf, log
 from module_build_service.common.koji import get_session
 from module_build_service.resolver import GenericResolver
 from module_build_service.scheduler.db_session import db_session
diff --git a/module_build_service/web/auth.py b/module_build_service/web/auth.py
index 256cd26b..b1690c6a 100644
--- a/module_build_service/web/auth.py
+++ b/module_build_service/web/auth.py
@@ -10,7 +10,8 @@ from dogpile.cache import make_region
 from flask import g
 import requests
 
-from module_build_service import app, log, conf
+from module_build_service import app
+from module_build_service.common import conf, log
 from module_build_service.common.errors import Unauthorized, Forbidden
 
 
diff --git a/module_build_service/web/backports.py b/module_build_service/web/backports.py
index f2c8c631..1729e6de 100644
--- a/module_build_service/web/backports.py
+++ b/module_build_service/web/backports.py
@@ -5,7 +5,7 @@ from __future__ import absolute_import
 from flask import request
 from flask.json import dumps
 
-import module_build_service
+from module_build_service import app
 
 
 def jsonify(*args, **kwargs):
@@ -16,7 +16,7 @@ def jsonify(*args, **kwargs):
     indent = None
     separators = (",", ":")
 
-    if module_build_service.app.config["JSONIFY_PRETTYPRINT_REGULAR"] and not request.is_xhr:
+    if app.config["JSONIFY_PRETTYPRINT_REGULAR"] and not request.is_xhr:
         indent = 2
         separators = (", ", ": ")
 
@@ -31,6 +31,6 @@ def jsonify(*args, **kwargs):
 
     # Note that we add '\n' to end of response
     # (see https://github.com/mitsuhiko/flask/pull/1262)
-    rv = module_build_service.app.response_class(
+    rv = app.response_class(
         (dumps(data, indent=indent, separators=separators), "\n"), mimetype="application/json")
     return rv
diff --git a/module_build_service/web/mmd_resolver.py b/module_build_service/web/mmd_resolver.py
index a641b03d..2b3be360 100644
--- a/module_build_service/web/mmd_resolver.py
+++ b/module_build_service/web/mmd_resolver.py
@@ -6,8 +6,7 @@ import itertools
 
 import solv
 
-from module_build_service import log, conf
-from module_build_service.common.models import ModuleBuild
+from module_build_service.common import log, conf, models
 
 
 class MMDResolver(object):
@@ -144,7 +143,8 @@ class MMDResolver(object):
                         # In case x.y.z versioning is not used for this base module, do not
                         # use versions solv.Dep.
                         stream_version_str = str(
-                            ModuleBuild.get_stream_version(stream_for_version, right_pad=False))
+                            models.ModuleBuild.get_stream_version(
+                                stream_for_version, right_pad=False))
                         if len(stream_version_str) < 5:
                             req_pos = rel_or_dep(
                                 req_pos, solv.REL_OR, self.module_dep(name, stream))
@@ -173,7 +173,7 @@ class MMDResolver(object):
                             op = solv.REL_EQ
                             if not exact_versions:
                                 op |= solv.REL_GT
-                            version = ModuleBuild.get_stream_version(
+                            version = models.ModuleBuild.get_stream_version(
                                 stream_for_version, right_pad=False
                             )
                             req_pos = rel_or_dep(
@@ -223,7 +223,8 @@ class MMDResolver(object):
         # and so on. We therefore need to convert the stream and version of base module to
         # integer representation and add "module($name:$stream) = $stream_based_version"
         # to Provides.
-        stream_version = ModuleBuild.get_stream_version(mmd.get_stream_name(), right_pad=False)
+        stream_version = models.ModuleBuild.get_stream_version(
+            mmd.get_stream_name(), right_pad=False)
         if stream_version:
             base_stream_ver = True
             self.solvable_provides(
diff --git a/module_build_service/web/mse.py b/module_build_service/web/mse.py
index a800db90..5c53216d 100644
--- a/module_build_service/web/mse.py
+++ b/module_build_service/web/mse.py
@@ -2,9 +2,9 @@
 # SPDX-License-Identifier: MIT
 from __future__ import absolute_import
 
-from module_build_service import log, Modulemd, conf
-from module_build_service.common import models
+from module_build_service.common import conf, log, models
 from module_build_service.common.errors import StreamAmbigous, UnprocessableEntity
+from module_build_service.common.modulemd import Modulemd
 from module_build_service.common.resolve import expand_single_mse_streams, get_base_module_mmds
 from module_build_service.common.utils import mmd_to_str
 from module_build_service.resolver import GenericResolver
diff --git a/module_build_service/web/submit.py b/module_build_service/web/submit.py
index 96d90362..15a74b11 100644
--- a/module_build_service/web/submit.py
+++ b/module_build_service/web/submit.py
@@ -11,10 +11,10 @@ import time
 from gi.repository import GLib
 import requests
 
-from module_build_service import conf, log, Modulemd
-from module_build_service.common import models
+from module_build_service.common import conf, log, models
 from module_build_service.common.errors import Conflict, Forbidden, ValidationError
 from module_build_service.common.messaging import notify_on_module_state_change
+from module_build_service.common.modulemd import Modulemd
 from module_build_service.common.submit import fetch_mmd
 from module_build_service.common.utils import load_mmd, mmd_to_str, to_text_type
 from module_build_service.web.mse import generate_expanded_mmds
diff --git a/module_build_service/web/utils.py b/module_build_service/web/utils.py
index c27afa43..3de81c9b 100644
--- a/module_build_service/web/utils.py
+++ b/module_build_service/web/utils.py
@@ -11,8 +11,8 @@ import sqlalchemy
 from sqlalchemy.orm import aliased
 from sqlalchemy.sql.sqltypes import Boolean as sqlalchemy_boolean
 
-from module_build_service import api_version, conf, db
-from module_build_service.common import models
+from module_build_service import api_version, db
+from module_build_service.common import conf, models
 from module_build_service.common.errors import ValidationError, NotFound
 from module_build_service.common.scm import scm_url_schemes
 
diff --git a/module_build_service/web/views.py b/module_build_service/web/views.py
index 75252f85..0488a1da 100644
--- a/module_build_service/web/views.py
+++ b/module_build_service/web/views.py
@@ -14,10 +14,11 @@ from flask.views import MethodView
 from prometheus_client import generate_latest, CONTENT_TYPE_LATEST
 from six import string_types
 
-from module_build_service import app, conf, log, db, version, api_version as max_api_version
-from module_build_service.common import models
+from module_build_service import app, db, version, api_version as max_api_version
+from module_build_service.common import conf, log, models
 from module_build_service.common.errors import (
-    ValidationError, Forbidden, NotFound, ProgrammingError
+    ValidationError, Forbidden, NotFound, ProgrammingError,
+    Unauthorized, UnprocessableEntity, Conflict
 )
 from module_build_service.common.models import send_message_after_module_build_state_change
 from module_build_service.common.monitor import registry
@@ -569,6 +570,55 @@ def register_api():
 register_api()
 
 
+def json_error(status, error, message):
+    response = jsonify({"status": status, "error": error, "message": message})
+    response.status_code = status
+    return response
+
+
+@app.errorhandler(ValidationError)
+def validationerror_error(e):
+    """Flask error handler for ValidationError exceptions"""
+    return json_error(400, "Bad Request", str(e))
+
+
+@app.errorhandler(Unauthorized)
+def unauthorized_error(e):
+    """Flask error handler for NotAuthorized exceptions"""
+    return json_error(401, "Unauthorized", str(e))
+
+
+@app.errorhandler(Forbidden)
+def forbidden_error(e):
+    """Flask error handler for Forbidden exceptions"""
+    return json_error(403, "Forbidden", str(e))
+
+
+@app.errorhandler(RuntimeError)
+def runtimeerror_error(e):
+    """Flask error handler for RuntimeError exceptions"""
+    log.exception("RuntimeError exception raised")
+    return json_error(500, "Internal Server Error", str(e))
+
+
+@app.errorhandler(UnprocessableEntity)
+def unprocessableentity_error(e):
+    """Flask error handler for UnprocessableEntity exceptions"""
+    return json_error(422, "Unprocessable Entity", str(e))
+
+
+@app.errorhandler(Conflict)
+def conflict_error(e):
+    """Flask error handler for Conflict exceptions"""
+    return json_error(409, "Conflict", str(e))
+
+
+@app.errorhandler(NotFound)
+def notfound_error(e):
+    """Flask error handler for Conflict exceptions"""
+    return json_error(404, "Not Found", str(e))
+
+
 # Ensure the event handler is called on db.session
 sqlalchemy.event.listen(
     db.session, "after_commit", send_message_after_module_build_state_change)
diff --git a/tests/__init__.py b/tests/__init__.py
index 62d18798..a724ac56 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -16,7 +16,7 @@ from mock import patch
 from six import string_types
 
 import module_build_service
-from module_build_service import db, Modulemd
+from module_build_service import db
 from module_build_service.builder.utils import get_rpm_release
 from module_build_service.common.models import (
     BUILD_STATES,
@@ -25,6 +25,7 @@ from module_build_service.common.models import (
     ModuleBuild,
     VirtualStream,
 )
+from module_build_service.common.modulemd import Modulemd
 from module_build_service.common.utils import load_mmd, import_mmd, mmd_to_str, to_text_type
 from module_build_service.scheduler.db_session import db_session
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 3a1c8f0c..7b660573 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -390,10 +390,10 @@ def cleanup_build_logs(request):
     """
 
     def _cleanup_build_logs():
-        build_ids = list(module_build_service.build_logs.handlers.keys())
+        build_ids = list(module_build_service.common.build_logs.handlers.keys())
         for build_id in build_ids:
             mock_build = mock.Mock()
             mock_build.id = build_id
-            module_build_service.build_logs.stop(mock_build)
+            module_build_service.common.build_logs.stop(mock_build)
 
     request.addfinalizer(_cleanup_build_logs)
diff --git a/tests/test_build/test_build.py b/tests/test_build/test_build.py
index 03f4b73a..8f84bf45 100644
--- a/tests/test_build/test_build.py
+++ b/tests/test_build/test_build.py
@@ -21,12 +21,12 @@ import moksha.hub
 import pytest
 from werkzeug.datastructures import FileStorage
 
-from module_build_service import app, conf, build_logs, log
+from module_build_service import app
 from module_build_service.builder import GenericBuilder
 from module_build_service.builder.KojiModuleBuilder import KojiModuleBuilder
 from module_build_service.builder.MockModuleBuilder import load_local_builds
 from module_build_service.builder.utils import get_rpm_release, validate_koji_tag
-from module_build_service.common import models
+from module_build_service.common import conf, log, build_logs, models
 from module_build_service.common.errors import Forbidden
 from module_build_service.common.utils import load_mmd, import_mmd
 from module_build_service.scheduler import events
diff --git a/tests/test_builder/test_builder_utils.py b/tests/test_builder/test_builder_utils.py
index dbad5db4..2ce9e0d4 100644
--- a/tests/test_builder/test_builder_utils.py
+++ b/tests/test_builder/test_builder_utils.py
@@ -7,9 +7,9 @@ import tempfile
 from mock import call, MagicMock, Mock, patch, PropertyMock
 import pytest
 
-from module_build_service import conf
 from module_build_service.builder import utils
 from module_build_service.common import models
+from module_build_service.common.config import conf
 from module_build_service.common.errors import ProgrammingError, ValidationError
 from module_build_service.common.utils import load_mmd, import_mmd, mmd_to_str
 from module_build_service.scheduler.db_session import db_session
diff --git a/tests/test_builder/test_content_generator.py b/tests/test_builder/test_content_generator.py
index 1b66de20..2391f237 100644
--- a/tests/test_builder/test_content_generator.py
+++ b/tests/test_builder/test_content_generator.py
@@ -11,9 +11,9 @@ import koji
 from mock import patch, Mock, call, mock_open
 import pytest
 
-from module_build_service import conf, build_logs, Modulemd
 from module_build_service.builder.KojiContentGenerator import KojiContentGenerator
-from module_build_service.common import models
+from module_build_service.common import conf, build_logs, models
+from module_build_service.common.modulemd import Modulemd
 from module_build_service.common.utils import load_mmd, load_mmd_file, mmd_to_str
 from module_build_service.scheduler.db_session import db_session
 from tests import init_data
diff --git a/tests/test_builder/test_koji.py b/tests/test_builder/test_koji.py
index 32ba8bb7..e3b03113 100644
--- a/tests/test_builder/test_koji.py
+++ b/tests/test_builder/test_koji.py
@@ -11,10 +11,11 @@ import mock
 from mock import patch, MagicMock
 import pytest
 
-from module_build_service import conf, Modulemd
 from module_build_service.builder import GenericBuilder
 from module_build_service.builder.KojiModuleBuilder import KojiModuleBuilder
 import module_build_service.common.models
+from module_build_service.common.config import conf
+from module_build_service.common.modulemd import Modulemd
 from module_build_service.common.utils import mmd_to_str
 from module_build_service.scheduler import events
 from module_build_service.scheduler.db_session import db_session
diff --git a/tests/test_builder/test_mock.py b/tests/test_builder/test_mock.py
index d1015a67..1f0c9d03 100644
--- a/tests/test_builder/test_mock.py
+++ b/tests/test_builder/test_mock.py
@@ -11,7 +11,7 @@ import koji
 import mock
 import pytest
 
-from module_build_service import conf
+from module_build_service.common.config import conf
 from module_build_service.builder.MockModuleBuilder import (
     import_fake_base_module,
     import_builds_from_local_dnf_repos,
@@ -122,7 +122,7 @@ class TestMockModuleBuilder:
 
         return module
 
-    @mock.patch("module_build_service.conf.system", new="mock")
+    @mock.patch("module_build_service.common.conf.system", new="mock")
     def test_createrepo_filter_last_batch(self):
         module = self._create_module_with_filters(db_session, 3, koji.BUILD_STATES["COMPLETE"])
 
@@ -149,7 +149,7 @@ class TestMockModuleBuilder:
             rpm_names = [kobo.rpmlib.parse_nvr(rpm)["name"] for rpm in pkglist.split("\n")]
             assert "ed" not in rpm_names
 
-    @mock.patch("module_build_service.conf.system", new="mock")
+    @mock.patch("module_build_service.common.conf.system", new="mock")
     def test_createrepo_not_last_batch(self):
         module = self._create_module_with_filters(db_session, 2, koji.BUILD_STATES["COMPLETE"])
 
@@ -174,7 +174,7 @@ class TestMockModuleBuilder:
             rpm_names = [kobo.rpmlib.parse_nvr(rpm)["name"] for rpm in pkglist.split("\n")]
             assert "ed" in rpm_names
 
-    @mock.patch("module_build_service.conf.system", new="mock")
+    @mock.patch("module_build_service.common.conf.system", new="mock")
     def test_createrepo_empty_rmp_list(self):
         module = self._create_module_with_filters(db_session, 3, koji.BUILD_STATES["COMPLETE"])
 
@@ -194,7 +194,7 @@ class TestMockModuleBuilderAddRepos:
     def setup_method(self, test_method):
         clean_database(add_platform_module=False)
 
-    @mock.patch("module_build_service.conf.system", new="mock")
+    @mock.patch("module_build_service.common.conf.system", new="mock")
     @mock.patch(
         "module_build_service.common.config.Config.base_module_repofiles",
         new_callable=mock.PropertyMock,
diff --git a/tests/test_common/test_config.py b/tests/test_common/test_config.py
index 275d9a19..ce525521 100644
--- a/tests/test_common/test_config.py
+++ b/tests/test_common/test_config.py
@@ -3,7 +3,7 @@
 from __future__ import absolute_import
 import os.path
 
-from module_build_service import conf
+from module_build_service.common.config import conf
 
 
 class TestConfig:
diff --git a/tests/test_common/test_logger.py b/tests/test_common/test_logger.py
index d5ef2f5b..9c6156b4 100644
--- a/tests/test_common/test_logger.py
+++ b/tests/test_common/test_logger.py
@@ -6,8 +6,7 @@ from os import path
 import shutil
 import tempfile
 
-from module_build_service import log
-from module_build_service.common import models
+from module_build_service.common import log, models
 from module_build_service.common.logger import ModuleBuildLogs
 from module_build_service.scheduler.consumer import MBSConsumer
 from module_build_service.scheduler.db_session import db_session
diff --git a/tests/test_common/test_models/test_models.py b/tests/test_common/test_models/test_models.py
index 65b0463a..426172a6 100644
--- a/tests/test_common/test_models/test_models.py
+++ b/tests/test_common/test_models/test_models.py
@@ -5,7 +5,7 @@ from __future__ import absolute_import
 from mock import patch
 import pytest
 
-from module_build_service import conf
+from module_build_service.common.config import conf
 from module_build_service.common.models import ComponentBuild, ComponentBuildTrace, ModuleBuild
 from module_build_service.common.utils import load_mmd, mmd_to_str
 from module_build_service.scheduler.db_session import db_session
diff --git a/tests/test_common/test_monitor.py b/tests/test_common/test_monitor.py
index d72f6fb4..88f3094f 100644
--- a/tests/test_common/test_monitor.py
+++ b/tests/test_common/test_monitor.py
@@ -8,8 +8,8 @@ import pytest
 import requests
 from six.moves import reload_module
 
-from module_build_service import app, conf
-from module_build_service.common import models
+from module_build_service import app
+from module_build_service.common import conf, models
 import module_build_service.common.monitor
 from module_build_service.scheduler.db_session import db_session
 from tests import clean_database, init_data, make_module_in_db
diff --git a/tests/test_common/test_resolve.py b/tests/test_common/test_resolve.py
index 0ca17f94..52e30608 100644
--- a/tests/test_common/test_resolve.py
+++ b/tests/test_common/test_resolve.py
@@ -5,8 +5,8 @@ from __future__ import absolute_import
 from mock import patch, PropertyMock
 import pytest
 
-from module_build_service import Modulemd
 from module_build_service.common import models
+from module_build_service.common.modulemd import Modulemd
 from module_build_service.common.utils import load_mmd
 from module_build_service.common.resolve import get_base_module_mmds
 from module_build_service.scheduler.db_session import db_session
diff --git a/tests/test_resolver/test_db.py b/tests/test_resolver/test_db.py
index 26974511..4020879c 100644
--- a/tests/test_resolver/test_db.py
+++ b/tests/test_resolver/test_db.py
@@ -7,11 +7,12 @@ from datetime import datetime
 from mock import patch, PropertyMock
 import pytest
 
-from module_build_service import conf, Modulemd
 from module_build_service.builder.MockModuleBuilder import load_local_builds
 from module_build_service.common import models
+from module_build_service.common.config import conf
 from module_build_service.common.errors import UnprocessableEntity
 from module_build_service.common.models import ModuleBuild
+from module_build_service.common.modulemd import Modulemd
 from module_build_service.common.utils import import_mmd, load_mmd, mmd_to_str
 import module_build_service.resolver as mbs_resolver
 from module_build_service.scheduler.db_session import db_session
diff --git a/tests/test_resolver/test_koji.py b/tests/test_resolver/test_koji.py
index 415fc802..44c2961f 100644
--- a/tests/test_resolver/test_koji.py
+++ b/tests/test_resolver/test_koji.py
@@ -6,7 +6,7 @@ from datetime import datetime
 from mock import patch, MagicMock
 import pytest
 
-from module_build_service import conf
+from module_build_service.common.config import conf
 from module_build_service.common.models import ModuleBuild, BUILD_STATES
 from module_build_service.common.utils import import_mmd, load_mmd, mmd_to_str
 import module_build_service.resolver as mbs_resolver
diff --git a/tests/test_resolver/test_local.py b/tests/test_resolver/test_local.py
index c01a57cc..2e39fb80 100644
--- a/tests/test_resolver/test_local.py
+++ b/tests/test_resolver/test_local.py
@@ -5,7 +5,7 @@ from datetime import datetime
 
 import pytest
 
-from module_build_service import conf
+from module_build_service.common.config import conf
 from module_build_service.common.models import ModuleBuild
 from module_build_service.common.utils import import_mmd, load_mmd, mmd_to_str
 from module_build_service.scheduler.db_session import db_session
diff --git a/tests/test_resolver/test_mbs.py b/tests/test_resolver/test_mbs.py
index d5930fbf..368faa24 100644
--- a/tests/test_resolver/test_mbs.py
+++ b/tests/test_resolver/test_mbs.py
@@ -4,9 +4,10 @@ from __future__ import absolute_import
 
 from mock import patch, PropertyMock, Mock, call
 
-from module_build_service import app, conf
+from module_build_service import app
 from module_build_service.builder.MockModuleBuilder import load_local_builds
 import module_build_service.common.models
+from module_build_service.common import conf
 from module_build_service.common.utils import load_mmd, mmd_to_str
 import module_build_service.resolver as mbs_resolver
 from module_build_service.scheduler.db_session import db_session
diff --git a/tests/test_scheduler/test_batches.py b/tests/test_scheduler/test_batches.py
index 0d3beb9a..161fc5af 100644
--- a/tests/test_scheduler/test_batches.py
+++ b/tests/test_scheduler/test_batches.py
@@ -7,7 +7,7 @@ import mock
 from mock import patch
 import pytest
 
-from module_build_service import conf
+from module_build_service.common.config import conf
 from module_build_service.builder import GenericBuilder
 from module_build_service.builder.KojiModuleBuilder import KojiModuleBuilder
 from module_build_service.builder.utils import validate_koji_tag
diff --git a/tests/test_scheduler/test_celery_route_task.py b/tests/test_scheduler/test_celery_route_task.py
index c8793ee5..25c8d779 100644
--- a/tests/test_scheduler/test_celery_route_task.py
+++ b/tests/test_scheduler/test_celery_route_task.py
@@ -4,7 +4,8 @@ from __future__ import absolute_import
 
 import mock
 
-from module_build_service import celery_app, conf
+from module_build_service.common.config import conf
+from module_build_service.scheduler import celery_app
 from module_build_service.scheduler.handlers import components, greenwave, modules, repos, tags
 from module_build_service.scheduler.producer import fail_lost_builds
 from tests import scheduler_init_data
diff --git a/tests/test_scheduler/test_db_session.py b/tests/test_scheduler/test_db_session.py
index ec32debc..da4386a0 100644
--- a/tests/test_scheduler/test_db_session.py
+++ b/tests/test_scheduler/test_db_session.py
@@ -3,8 +3,8 @@
 
 from mock import patch
 
-from module_build_service import conf
 from module_build_service.common import models
+from module_build_service.common.config import conf
 from module_build_service.scheduler.db_session import db_session
 from tests import clean_database, make_module_in_db
 
diff --git a/tests/test_scheduler/test_default_modules.py b/tests/test_scheduler/test_default_modules.py
index 64186a4b..f7334db4 100644
--- a/tests/test_scheduler/test_default_modules.py
+++ b/tests/test_scheduler/test_default_modules.py
@@ -8,7 +8,7 @@ import dnf
 from mock import call, Mock, patch, PropertyMock
 import pytest
 
-from module_build_service import conf
+from module_build_service.common.config import conf
 from module_build_service.common.errors import UnprocessableEntity
 from module_build_service.common.models import ModuleBuild
 from module_build_service.common.utils import import_mmd, load_mmd, mmd_to_str
diff --git a/tests/test_scheduler/test_greenwave_handler.py b/tests/test_scheduler/test_greenwave_handler.py
index 6b27b122..076b8f4b 100644
--- a/tests/test_scheduler/test_greenwave_handler.py
+++ b/tests/test_scheduler/test_greenwave_handler.py
@@ -7,7 +7,7 @@ import pytest
 from sqlalchemy import func
 
 
-from module_build_service import conf
+from module_build_service.common.config import conf
 import module_build_service.common.config
 from module_build_service.common.models import BUILD_STATES, ModuleBuild
 from module_build_service.scheduler.consumer import MBSConsumer
diff --git a/tests/test_scheduler/test_module_init.py b/tests/test_scheduler/test_module_init.py
index 6abb23ba..3978c257 100644
--- a/tests/test_scheduler/test_module_init.py
+++ b/tests/test_scheduler/test_module_init.py
@@ -5,7 +5,7 @@ import os
 
 from mock import patch, PropertyMock
 
-from module_build_service import build_logs, conf
+from module_build_service.common import build_logs, conf
 from module_build_service.common.models import BUILD_STATES, ModuleBuild
 from module_build_service.common.utils import load_mmd, mmd_to_str
 from module_build_service.scheduler.db_session import db_session
diff --git a/tests/test_scheduler/test_module_wait.py b/tests/test_scheduler/test_module_wait.py
index 9aca0f62..4a31d717 100644
--- a/tests/test_scheduler/test_module_wait.py
+++ b/tests/test_scheduler/test_module_wait.py
@@ -8,8 +8,9 @@ import mock
 from mock import patch
 import pytest
 
-from module_build_service import build_logs, conf, Modulemd
+from module_build_service.common import build_logs, conf
 from module_build_service.common.models import ComponentBuild, ModuleBuild
+from module_build_service.common.modulemd import Modulemd
 import module_build_service.resolver
 from module_build_service.scheduler.db_session import db_session
 import module_build_service.scheduler.handlers.modules
diff --git a/tests/test_scheduler/test_poller.py b/tests/test_scheduler/test_poller.py
index 6fb28fbf..bbc836ef 100644
--- a/tests/test_scheduler/test_poller.py
+++ b/tests/test_scheduler/test_poller.py
@@ -9,7 +9,7 @@ import mock
 from mock import call, patch
 import pytest
 
-from module_build_service import conf
+from module_build_service.common.config import conf
 from module_build_service.common import models
 from module_build_service.scheduler import producer
 from module_build_service.scheduler.db_session import db_session
diff --git a/tests/test_scheduler/test_reuse.py b/tests/test_scheduler/test_reuse.py
index 2cdef47b..a7e701af 100644
--- a/tests/test_scheduler/test_reuse.py
+++ b/tests/test_scheduler/test_reuse.py
@@ -6,8 +6,8 @@ import mock
 import pytest
 from sqlalchemy.orm.session import make_transient
 
-from module_build_service import Modulemd
 from module_build_service.common import models
+from module_build_service.common.modulemd import Modulemd
 from module_build_service.common.utils import import_mmd, load_mmd, mmd_to_str
 from module_build_service.scheduler.db_session import db_session
 from module_build_service.scheduler.reuse import get_reusable_component, get_reusable_module
diff --git a/tests/test_scheduler/test_submit.py b/tests/test_scheduler/test_submit.py
index 4bee0e22..c98b7f82 100644
--- a/tests/test_scheduler/test_submit.py
+++ b/tests/test_scheduler/test_submit.py
@@ -6,8 +6,8 @@ from datetime import datetime
 import mock
 import pytest
 
-from module_build_service import app, conf
-from module_build_service.common import models
+from module_build_service import app
+from module_build_service.common import conf, models
 from module_build_service.common.errors import UnprocessableEntity
 from module_build_service.common.utils import load_mmd, load_mmd_file, mmd_to_str
 from module_build_service.scheduler.db_session import db_session
diff --git a/tests/test_scheduler/test_ursine.py b/tests/test_scheduler/test_ursine.py
index 68176fc8..3a0df126 100644
--- a/tests/test_scheduler/test_ursine.py
+++ b/tests/test_scheduler/test_ursine.py
@@ -4,7 +4,7 @@ from __future__ import absolute_import
 
 from mock import patch, Mock
 
-from module_build_service import conf
+from module_build_service.common.config import conf
 from module_build_service.scheduler import ursine
 from tests import make_module, make_module_in_db, clean_database