CA-395221: use systemd target for gc enable

The xapi enabled state does not reflect whether the local xapi process
is able to respond to requests and only whether the host is enabled to
run new VMs. It is therefore not a useful check to ensure the GC will
be able to make requests of xapi. Switch instead to making the
service require the xapi-init-complete.target which will at least
ensure the local xapi has completed its initialisation which was the
original intent of this check.

Signed-off-by: Mark Syms <mark.syms@cloud.com>

Author: MarkSymsCtx

libs/sm/cleanup.py

@@ -3115,32 +3115,8 @@ def _gcLoop(sr, dryRun=False, immediate=False):
         lockGCActive.release()
 
 
-def _xapi_enabled(session, hostref):
-    host = session.xenapi.host.get_record(hostref)
-    return host['enabled']
-
-
-def _ensure_xapi_initialised(session):
-    """
-    Don't want to start GC until Xapi is fully initialised
-    """
-    local_session = None
-    if session is None:
-        local_session = util.get_localAPI_session()
-        session = local_session
-
-    try:
-        hostref = session.xenapi.host.get_by_uuid(util.get_this_host())
-        while not _xapi_enabled(session, hostref):
-            util.SMlog("Xapi not ready, GC waiting")
-            time.sleep(15)
-    finally:
-        if local_session is not None:
-            local_session.xenapi.session.logout()
-
 def _gc(session, srUuid, dryRun=False, immediate=False):
     init(srUuid)
-    _ensure_xapi_initialised(session)
     sr = SR.getInstance(srUuid, session)
     if not sr.gcEnabled(False):
         return

systemd/SMGC@.service

@@ -1,6 +1,7 @@
 [Unit]
 Description=Garbage Collector for SR %I
 DefaultDependencies=no
+Requires=xapi-init-complete.target
 
 [Service]
 Type=oneshot

tests/test_cleanup.py

@@ -184,8 +184,7 @@ def test_term_handler(self):
 
     @mock.patch('sm.cleanup._create_init_file', autospec=True)
     @mock.patch('sm.cleanup.SR', autospec=True)
-    @mock.patch('sm.cleanup._ensure_xapi_initialised', autospec=True)
-    def test_loop_exits_on_term(self, mock_init, mock_sr, mock_check_xapi):
+    def test_loop_exits_on_term(self, mock_init, mock_sr):
         # Set the term signel
         cleanup.receiveSignal(signal.SIGTERM, None)
         mock_session = mock.MagicMock(name='MockSession')
@@ -1680,71 +1679,6 @@ def test_tag_children_for_relink_blocked(self):
 
         self.assertGreater(self.mock_time_sleep.call_count, 5)
 
-    @mock.patch('sm.cleanup.util.get_this_host', autospec=True)
-    @mock.patch('sm.cleanup._gcLoop', autospec=True)
-    @mock.patch('sm.cleanup.SR.getInstance')
-    def test_check_for_xapi_running(
-            self, mock_sr, mock_loop, mock_this_host):
-        """
-        Check we start immediately if xapi is enabled
-        """
-        host_uuid = uuid4()
-        mock_this_host.return_value = host_uuid
-
-        mock_session = mock.MagicMock(name='MockSession')
-        mock_session.xenapi.host.get_record.return_value = {
-            'enabled': True
-        }
-        sr_uuid = uuid4()
-
-        cleanup._gc(mock_session, sr_uuid, False)
-
-    @mock.patch('sm.cleanup.util.get_this_host', autospec=True)
-    @mock.patch('sm.cleanup.util.get_localAPI_session', autospec=True)
-    @mock.patch('sm.cleanup._gcLoop', autospec=True)
-    @mock.patch('sm.cleanup.SR.getInstance')
-    def test_check_for_xapi_running_no_session(
-            self, mock_sr, mock_loop, mock_get_session, mock_this_host):
-        """
-        Check we start immediately if xapi is enabled
-        """
-        host_uuid = uuid4()
-        mock_this_host.return_value = host_uuid
-        mock_session = mock.MagicMock(name='MockSession')
-        mock_get_session.return_value = mock_session
-
-        mock_session.xenapi.host.get_record.return_value = {
-            'enabled': True
-        }
-        sr_uuid = uuid4()
-
-        cleanup._gc(None, sr_uuid, False)
-
-    @mock.patch('sm.cleanup.util.get_this_host', autospec=True)
-    @mock.patch('sm.cleanup.util.get_localAPI_session', autospec=True)
-    @mock.patch('sm.cleanup._gcLoop', autospec=True)
-    @mock.patch('sm.cleanup.SR.getInstance')
-    def test_waits_for_xapi_running(
-            self, mock_sr, mock_loop, mock_get_session, mock_this_host):
-        """
-        Check we start immediately if xapi is enabled
-        """
-        host_uuid = uuid4()
-        mock_this_host.return_value = host_uuid
-        mock_session = mock.MagicMock(name='MockSession')
-        mock_get_session.return_value = mock_session
-
-        mock_session.xenapi.host.get_record.side_effect = [
-            {'enabled': False},
-            {'enabled': False},
-            {'enabled': True}
-        ]
-        sr_uuid = uuid4()
-
-        cleanup._gc(None, sr_uuid, False)
-
-        self.assertEqual(3, mock_session.xenapi.host.get_record.call_count)
-
     def init_gc_loop_sr(self):
         sr_uuid = str(uuid4())
         mock_sr = mock.MagicMock(spec=cleanup.SR)