replacing run.sh with a "docker-registry" console script

Author: mhrivnak

Dockerfile

@@ -20,8 +20,8 @@ ADD ./config/boto.cfg /etc/boto.cfg
 
 RUN pip install /docker-registry/
 
-RUN cp --no-clobber /docker-registry/config/config_sample.yml /docker-registry/config/config.yml
+ENV DOCKER_REGISTRY_CONFIG /docker-registry/config/config_sample.yml
 
 EXPOSE 5000
 
-CMD cd /docker-registry && ./setup-configs.sh && exec ./run.sh
+CMD cd /docker-registry && ./setup-configs.sh && exec docker-registry

README.md

@@ -298,7 +298,7 @@ sudo python-pip install .
 #### Run it
 
 ```
-gunicorn --access-logfile - --debug -k gevent -b 0.0.0.0:5000 -w 1 wsgi:application
+gunicorn --access-logfile - --debug -k gevent -b 0.0.0.0:5000 -w 1 docker_registry.wsgi:application
 ```
 
 ### How do I setup user accounts?
@@ -315,7 +315,7 @@ You could use for instance supervisord to spawn the registry with 8 workers
 using this command:
 
 ```
-gunicorn -k gevent --max-requests 100 --graceful-timeout 3600 -t 3600 -b localhost:5000 -w 8 wsgi:application
+gunicorn -k gevent --max-requests 100 --graceful-timeout 3600 -t 3600 -b localhost:5000 -w 8 docker_registry.wsgi:application
 ```
 
 Note that when using multiple workers, the secret_key for the Flask session

docker_registry/__init__.py

@@ -1,6 +1,18 @@
 # -*- coding: utf-8 -*-
 # flake8: noqa
 
+from __future__ import print_function
+
+# this must happen before anything else
+import gevent.monkey
+gevent.monkey.patch_all()
+
+from argparse import ArgumentParser
+from argparse import RawTextHelpFormatter
+import distutils.spawn
+import os
+import sys
+
 from .app import app
 from .tags import *
 from .images import *
@@ -11,3 +23,42 @@
 if cfg.standalone is not False:
     # If standalone mode is enabled (default), load the fake Index routes
     from .index import *
+
+
+DESCRIPTION = """run the docker-registry with gunicorn, honoring the following environment variables:
+
+GUNICORN_WORKERS: number of worker processes gunicorn should start
+REGISTRY_PORT: TCP port to bind to on all ipv4 addresses; default is 5000
+GUNICORN_GRACEFUL_TIMEOUT: timeout in seconds for graceful worker restart
+GUNiCORN_SILENT_TIMEOUT: timeout in seconds for restarting silent workers
+"""
+
+
+def run_gunicorn():
+    """
+    Exec gunicorn with our wsgi app, taking settings from environment
+    variables as listed in the help text. This is intended to be called as a
+    console_script entry point.
+    """
+
+    # this only exists to provide help/usage text
+    parser = ArgumentParser(description=DESCRIPTION,
+                            formatter_class=RawTextHelpFormatter)
+    parser.parse_args()
+
+    workers = os.environ.get('GUNICORN_WORKERS', '4')
+    port = os.environ.get('REGISTRY_PORT', '5000')
+    graceful_timeout = os.environ.get('GUNICORN_GRACEFUL_TIMEOUT', '3600')
+    silent_timeout = os.environ.get('GUNICORN_SILENT_TIMEOUT', '3600')
+
+    address = '0.0.0.0:{0}'.format(port)
+
+    gunicorn_path = distutils.spawn.find_executable('gunicorn')
+    if gunicorn_path is None:
+        print('error: gunicorn executable not found', file=sys.stderr)
+        sys.exit(1)
+
+    os.execl(gunicorn_path, 'gunicorn', '--access-logfile', '-', '--debug',
+             '--max-requests', '100', '--graceful-timeout', graceful_timeout,
+             '-t', silent_timeout, '-k', 'gevent', '-b', address, '-w', workers,
+             'docker_registry.wsgi:application')

wsgi.py renamed to docker_registry/wsgi.py

@@ -4,25 +4,24 @@
 import logging
 import os
 
-import docker_registry
+from . import app
 
 
 if __name__ == '__main__':
     # Bind to PORT if defined, otherwise default to 5000.
     port = int(os.environ.get('PORT_WWW', 5000))
-    docker_registry.app.debug = True
-    docker_registry.app.run(host='0.0.0.0', port=port)
+    app.debug = True
+    app.run(host='0.0.0.0', port=port)
     # Or you can run:
     # gunicorn --access-logfile - --log-level debug --debug -b 0.0.0.0:5000 \
     #  -w 1 wsgi:application
 else:
     # For uwsgi
-    docker_registry.app.logger.setLevel(logging.INFO)
+    app.logger.setLevel(logging.INFO)
     stderr_logger = logging.StreamHandler()
     stderr_logger.setLevel(logging.INFO)
     stderr_logger.setFormatter(
         logging.Formatter('%(asctime)s %(levelname)s: %(message)s'))
-    docker_registry.app.logger.addHandler(stderr_logger)
-    application = docker_registry.app
-    # uwsgi
-    app = application
+    app.logger.addHandler(stderr_logger)
+
+    application = app

run.sh

@@ -29,5 +29,10 @@
         'License :: OSI Approved :: Apache Software License',
         'Programming Language :: Python',
         'Programming Language :: Python :: 2',
-    )
+    ),
+    entry_points={
+        'console_scripts': [
+            'docker-registry = docker_registry:run_gunicorn'
+        ]
+    }
 )

setup.py

@@ -0,0 +1,38 @@
+import unittest
+
+import mock
+
+import docker_registry
+
+
+class TestRunGunicorn(unittest.TestCase):
+    @mock.patch('argparse.ArgumentParser.parse_args')
+    @mock.patch('os.execl')
+    def test_exec_gunicorn(self, mock_execl, mock_parse_args):
+        docker_registry.run_gunicorn()
+
+        self.assertEqual(mock_execl.call_count, 1)
+        # ensure that the executable's path ends with 'gunicorn', so we have
+        # some confidence that it called the correct executable
+        self.assertTrue(mock_execl.call_args[0][0].endswith('gunicorn'))
+
+    @mock.patch('argparse.ArgumentParser.parse_args')
+    @mock.patch('os.execl')
+    def test_parses_args(self, mock_execl, mock_parse_args):
+        docker_registry.run_gunicorn()
+
+        # ensure that argument parsing is happening
+        mock_parse_args.assert_called_once_with()
+
+    @mock.patch('sys.exit')
+    @mock.patch('distutils.spawn.find_executable', autospec=True)
+    @mock.patch('argparse.ArgumentParser.parse_args')
+    @mock.patch('os.execl')
+    def test_gunicorn_not_found(self, mock_execl, mock_parse_args,
+                                mock_find_exec, mock_exit):
+        mock_find_exec.return_value = None
+
+        docker_registry.run_gunicorn()
+
+        # ensure that sys.exit was called
+        mock_exit.assert_called_once_with(1)