Failed action due to locked file made more verbose

Fixes issue where a failed action due to a locked file returns an exit
status of 0 and shows a status of "complete". The failed action now
returns exit status 2, and the message is more verbose. Added actions
file to handle all actions with symbolic links to said file.

Closes-Bug: #1940965
Change-Id: Ie950efee8d1052d33274b0fe07ff81f343e9f3e6

actions/actions.py

@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+#
+# Copyright 2023 Canonical Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#  http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import sys
+import subprocess
+
+_path = os.path.dirname(os.path.realpath(__file__))
+_root = os.path.abspath(os.path.join(_path, ".."))
+
+
+def _add_path(path):
+    if path not in sys.path:
+        sys.path.insert(1, path)
+
+
+_add_path(_root)
+
+
+from charmhelpers.core.hookenv import action_fail
+
+PID_FILE_DIR = "/var/run"
+RUNNING_FLAG_FILE_NAME = os.path.join(
+    PID_FILE_DIR, "glance-simplestreams-sync.pid"
+)
+
+
+def sync_images(args):
+    """Syncs images on local glance instance with the URL provided in the
+    config's mirror list
+    """
+    exit_status = subprocess.call(
+        [("/usr/share/glance-simplestreams-sync/"
+         "glance-simplestreams-sync.sh")]
+    )
+    if exit_status == 2:
+        action_fail("{} is locked, exiting".format(RUNNING_FLAG_FILE_NAME))
+    return exit_status
+
+
+# A dictionary of all the defined actions to callables (which take
+# parsed arguments).
+ACTIONS = {"sync-images": sync_images}
+
+
+def main(args):
+    action_name = os.path.basename(args[0])
+    try:
+        action = ACTIONS[action_name]
+    except KeyError:
+        return "Action {} undefined".format(action_name)
+    else:
+        try:
+            action(args)
+        except Exception as e:
+            action_fail(str(e))
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv))

actions/sync-images

@@ -1,5 +0,0 @@
-#!/bin/bash
-
-set -e
-
-/usr/share/glance-simplestreams-sync/glance-simplestreams-sync.sh

actions/sync-images

@@ -0,0 +1 @@
+actions.py

files/glance_simplestreams_sync.py

@@ -575,7 +575,7 @@ def main():
         fcntl.flock(lockfile, fcntl.LOCK_EX | fcntl.LOCK_NB)
     except IOError:
         log.info("{} is locked, exiting".format(SYNC_RUNNING_FLAG_FILE_NAME))
-        sys.exit(0)
+        sys.exit(2)
 
     returncode = 0
     atexit.register(cleanup)

unit_tests/test_actions.py

@@ -0,0 +1,71 @@
+#!/usr/bin/env python3
+
+"""
+Copyright 2023 Canonical Ltd.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+"""
+
+import os
+import sys
+import unittest.mock as mock
+import unittest
+
+_path = os.path.dirname(os.path.realpath(__file__))
+_actions = os.path.abspath(os.path.join(_path, "../actions"))
+
+
+def _add_path(path):
+    if path not in sys.path:
+        sys.path.insert(1, path)
+
+
+_add_path(_actions)
+
+import actions
+
+
+class TestActions(unittest.TestCase):
+    def test_add_path(self):
+        # random string as a path to add
+        newPath = "8zdyhfcnoqe08yhzxzc"
+        # Path should get added when it doesn't exist
+        actions._add_path(newPath)
+        self.assertEqual(sys.path.count(newPath), 1)
+        # Path shouldn't be added when it does exist
+        actions._add_path(newPath)
+        self.assertEqual(sys.path.count(newPath), 1)
+
+    @mock.patch("actions.action_fail")
+    @mock.patch("subprocess.call")
+    def test_sync_images(self, mock_subprocess_call, mock_action_fail):
+        # test pass, action_fail not called:
+        mock_subprocess_call.return_value = 0
+        self.assertEqual(actions.sync_images(None), 0, "Expect exit status 0")
+        self.assertFalse(mock_action_fail.called, "Should not call")
+
+        # test fail - unknown reason, action_fail not called:
+        mock_subprocess_call.return_value = 1
+        self.assertEqual(actions.sync_images(None), 1, "Expect exit status 1")
+        self.assertFalse(mock_action_fail.called, "Should not call")
+
+        # test fail - locked file, action_fail called:
+        mock_subprocess_call.return_value = 2
+        actions.sync_images(None)
+        # check if action_fail has been called exactly once
+        mock_action_fail.assert_called_once()
+        # check arguments with which it was called
+        FILE_PATH = os.path.join("/var/run", "glance-simplestreams-sync.pid")
+        mock_action_fail.assert_called_once_with(
+            "{} is locked, exiting".format(FILE_PATH)
+        )