AWX code changes for rsyslog decoupling (#13222)

* add management command and logging for new daemon
* switch tasks over to calling pg_notify
* add daemon to docker-compose and supervisor
* renamed handle_setting_changes and moved notify call
* removed initial rsyslog configure from dispatcher
* add logging and clear cache before reconfigure
* add notify to delete
* moved pg_notify to own function
* update tests impacted by rsyslog change
* changed over to new pg_notify method

Signed-off-by: Jessica Mack <jmack@redhat.com>

awx/main/management/commands/run_rsyslog_configurer.py

@@ -0,0 +1,38 @@
+import logging
+
+from django.core.management.base import BaseCommand
+from django.conf import settings
+from django.core.cache import cache
+from awx.main.dispatch import pg_bus_conn
+from awx.main.utils.external_logging import reconfigure_rsyslog
+
+logger = logging.getLogger('awx.main.rsyslog_configurer')
+
+
+class Command(BaseCommand):
+    """
+    Rsyslog Configurer
+    Runs as a management command and starts rsyslog configurer daemon. Daemon listens
+    for pg_notify then calls reconfigure_rsyslog
+    """
+
+    help = 'Launch the rsyslog_configurer daemon'
+
+    def handle(self, *arg, **options):
+        try:
+            with pg_bus_conn(new_connection=True) as conn:
+                conn.listen("rsyslog_configurer")
+                # reconfigure rsyslog on start up
+                reconfigure_rsyslog()
+                for e in conn.events(yield_timeouts=True):
+                    if e is not None:
+                        logger.info("Change in logging settings found. Restarting rsyslogd")
+                        # clear the cache of relevant settings then restart
+                        setting_keys = [k for k in dir(settings) if k.startswith('LOG_AGGREGATOR')]
+                        cache.delete_many(setting_keys)
+                        settings._awx_conf_memoizedcache.clear()
+                        reconfigure_rsyslog()
+        except Exception:
+            # Log unanticipated exception in addition to writing to stderr to get timestamps and other metadata
+            logger.exception('Encountered unhandled error in rsyslog_configurer main loop')
+            raise