Keep tags (#48)

* rebase

* docs

* remove extra spaces

* remove extra spaces

* remove user install

* save 5s

README.md

@@ -15,7 +15,7 @@ A python-based alternative to [watchtower](https://github.com/v2tec/watchtower)
 
 ## Overview
 
-Ouroboros will monitor all running docker containers or those you specify and update said containers to the latest available image in the remote registry using the `latest` tag with the same parameters that were used when the container was first created such as volume/bind mounts, docker network connections, environment variables, restart policies, entrypoints, commands, etc.
+Ouroboros will monitor all running docker containers or those you specify and update said containers to the latest available image in the remote registry using the `latest` tag with the same parameters that were used when the container was first created such as volume/bind mounts, docker network connections, environment variables, restart policies, entrypoints, commands, etc. While ouroboros updates images to `latest` by default, that can be [overridden](#Options) to only monitor updates of a specific tag. Similar to [watchtower](https://github.com/v2tec/watchtower).
 
 - Push your image to your registry and simply wait a couple of minutes for ouroboros to find the new image and redeploy your container autonomously.
 - Limit your server ssh access
@@ -97,6 +97,9 @@ docker run --rm circa10a/ouroboros --help
 - `--cleanup`, `-c` Remove the older docker image if a new one is found and updated.
   - Default is `False`.
   - Environment variable: `CLEANUP=true`
+- `--keep-tag`, `-k` Only monitor if updates are made to the tag of the image that the container was created with instead of using `latest`.
+  - Default is `False`.
+  - Environment variable: `KEEPTAG=true`
 
 ### Private Registries
 
@@ -120,6 +123,16 @@ docker run -d --name ouroboros \
 
 ## Examples
 
+### Monitor for updates for original tag
+ Instead of always updating to `latest` you can specify if you would like Ouroboros to only check for updates for your original container's image tag.
+ e.g. If your container was start with `nginx:1.14-alpine` using `--keep-tag` will poll the docker registry and compare digests. If there is a new image for `nginx:1.14-alpine`, ouroboros will update your container using the newly patched version.
+ > Default is `False`
+ ```bash
+docker run -d --name ouroboros \
+  -v /var/run/docker.sock:/var/run/docker.sock \
+  circa10a/ouroboros --keep-tag
+```
+
 ### Update containers on a remote host
 
 Ouroboros can monitor things other than just local, pass the `--url` argument to update a system with the Docker API exposed.

ouroboros/cli.py

@@ -53,24 +53,27 @@ def parse(sysargs):
     parser.add_argument('-u', '--url', default=defaults.LOCAL_UNIX_SOCKET,
                         help='Url for tcp host (defaults to "unix://var/run/docker.sock")')
 
-    parser.add_argument('-i', '--interval', type=int, default=get_interval_env() or defaults.INTERVAL, dest="interval",
+    parser.add_argument('-i', '--interval', type=int, default=get_interval_env() or defaults.INTERVAL, dest='interval',
                         help='Interval in seconds between checking for updates (defaults to 300s)')
 
-    parser.add_argument('-m', '--monitor', nargs='+', default=environ.get('MONITOR') or [], dest="monitor",
+    parser.add_argument('-m', '--monitor', nargs='+', default=environ.get('MONITOR') or [], dest='monitor',
                         help='Which container to monitor (defaults to all running).')
 
     parser.add_argument('-n', '--ignore', nargs='+', default=environ.get('IGNORE') or [], dest='ignore',
                         help='Which container(s) to ignore.')
 
     parser.add_argument('-l', '--loglevel', choices=['notset', 'debug', 'info', 'warn', 'error', 'critical'],
-                        dest="loglevel", default=environ.get('LOGLEVEL') or 'info',
+                        dest='loglevel', default=environ.get('LOGLEVEL') or 'info',
                         help='Change logger mode (defaults to info)')
 
-    parser.add_argument('-r', '--runonce', default=environ.get('RUNONCE') or False, dest="run_once",
+    parser.add_argument('-r', '--runonce', default=environ.get('RUNONCE') or False, dest='run_once',
                         help='Only run ouroboros once then exit', action='store_true')
 
-    parser.add_argument('-c', '--cleanup', default=environ.get('CLEANUP') or False, dest="cleanup",
+    parser.add_argument('-c', '--cleanup', default=environ.get('CLEANUP') or False, dest='cleanup',
                         help='Remove old images after updating', action='store_true')
+
+    parser.add_argument('-k', '--keep-tag', default=environ.get('KEEPTAG') or False, dest='keep_tag',
+                        help='Check for image updates of the same tag instead of pulling latest', action='store_true')
     args = parser.parse_args(sysargs)
 
     if not args.url:
@@ -80,6 +83,3 @@ def parse(sysargs):
             args.url = args.url if checkURI(args.url) else defaults.LOCAL_UNIX_SOCKET
 
     return args
-
-
-

ouroboros/defaults.py

@@ -4,3 +4,4 @@
 LOGLEVEL = 'info'
 RUNONCE = False
 CLEANUP = False
+KEEPTAG = False

ouroboros/image.py

@@ -13,9 +13,11 @@ def check_credentials():
     return {}
 
 
-def pull_latest(image, api_client):
+def pull_latest(image, keep_tag, api_client):
     """Return tag of latest image pulled"""
     latest_image = image['RepoTags'][0].split(':')[0] + ':latest'
+    if keep_tag:
+        latest_image = image['RepoTags'][0]
     log.debug(f'Pulling image: {latest_image}')
     api_client.pull(latest_image, auth_config=check_credentials())
     return api_client.inspect_image(latest_image)

ouroboros/main.py

@@ -16,7 +16,7 @@ def main(args, api_client):
             current_image = api_client.inspect_image(running_container['Config']['Image'])
 
             try:
-                latest_image = image.pull_latest(image=current_image, api_client=api_client)
+                latest_image = image.pull_latest(image=current_image, keep_tag=args.keep_tag, api_client=api_client)
             except docker.errors.APIError as e:
                 log.error(e)
                 continue

run_tests.sh

@@ -10,7 +10,7 @@ cd "$( dirname "$0" )"
 function list_missing_modules {
   comm -2 -3 \
   <( sort ./requirements-dev.txt ) \
-  <( pip list format=columns | awk '$0=$1' | sort )
+  <( pip list --format=columns | awk '$0=$1' | sort )
 }
 
 # create associative array of missing modules

setup.py

@@ -13,7 +13,7 @@ def read_reqs(requirements):
 
 setup(
     name='ouroboros-cli',
-    version='0.2.2',
+    version='0.2.3',
     description='Automatically update running docker containers',
     long_description=readme(),
     long_description_content_type='text/markdown',

tests/integration/main_test.py

@@ -59,7 +59,7 @@ def test_create_container():
 def test_main(mocker, caplog):
     mocker.patch('sys.argv', [''])
     mocker.patch.dict('os.environ',
-                      {'INTERVAL': '6',
+                      {'INTERVAL': '1',
                        'LOGLEVEL': 'debug',
                        'RUNONCE': 'true',
                        'CLEANUP': 'true',
@@ -79,8 +79,7 @@ def test_container_updated(mocker):
         f"{test_container_props['ports'][0]}/tcp"][0]['HostPort']
     assert new_container['State']['Status'] == 'running'
     assert new_container['Config']['Image'] == f'{test_repo}:latest'
-    assert new_container['Config']['Cmd'] == test_container_props['command'].split(
-    )
+    assert new_container['Config']['Cmd'] == test_container_props['command'].split()
     assert test_container_props['environment'][0] in new_container['Config']['Env']
     assert new_container['Mounts'][0]['Source'] == test_container_props['volumes'][0]
     assert new_container['Mounts'][0]['Destination'] == test_container_mount_dest

tests/unit/cli_test.py

@@ -145,3 +145,24 @@ def test_cleanup_env_var(mocker, cleanup_env_var, cleanup_env_var_result):
     mocker.patch('ouroboros.cli')
     args = cli.parse([])
     assert args.cleanup == cleanup_env_var_result
+
+
+@pytest.mark.parametrize('keeptag_args, keeptag_result', [
+    (['-k', ], True),
+    (['--keep-tag', ], True)
+])
+def test_keeptag_args(mocker, keeptag_args, keeptag_result):
+    mocker.patch('ouroboros.cli')
+    args = cli.parse(keeptag_args)
+    assert args.keep_tag == keeptag_result
+
+
+@pytest.mark.parametrize('keeptag_env_var, keeptag_env_var_result', [
+    ({'KEEPTAG': 'true'}, 'true'),
+    ({'_KEEPTAG': ''}, defaults.KEEPTAG),
+])
+def test_keeptag_env_var(mocker, keeptag_env_var, keeptag_env_var_result):
+    mocker.patch.dict('os.environ', keeptag_env_var)
+    mocker.patch('ouroboros.cli')
+    args = cli.parse([])
+    assert args.keep_tag == keeptag_env_var_result

tests/unit/main_unit_test.py

@@ -33,6 +33,7 @@ def test_main_full(fake_namespace, fake_api, caplog):
     fake_namespace.monitor = ["testName1"]
     fake_namespace.ignore = ["derp"]
     fake_namespace.cleanup = True
+    fake_namespace.keep_tag = True
 
     fake_api.inspect_container.return_value = container_object # called twice
     fake_api.containers.return_value = [container_object] # called twice
@@ -64,6 +65,7 @@ def test_main_exception(fake_namespace, fake_api, caplog):
     fake_namespace.monitor = ["testName1"]
     fake_namespace.ignore = ["derp"]
     fake_namespace.cleanup = True
+    fake_namespace.keep_tag = True
 
     fake_api.inspect_container.return_value = container_object  # called twice
     fake_api.containers.return_value = [container_object]  # called twice