Feat: Do vitality checks without sending heartbeat

config/sample-docker.engine.ini

@@ -32,12 +32,12 @@ from_mail="${ENGINE_MONITORING_SENDER_MAILADDRESS}"
 # A subject prefix allows applying filter rules in your mail client
 mailsubject_prefix="${ENGINE_MONITORING_MAIL_SUBJECT_PREFIX}" # default: [AURA Engine]
 
-# Server where heartbeat info is sent to
+# Seconds how often the vitality of Engine Core should be checked (default=1)
+heartbeat_frequency=${ENGINE_HEARTBEAT_FREQUENCY}
+# Host where heartbeat is sent to (disabled if empty string)
 heartbeat_server="${ENGINE_HEARTBEAT_SERVER}"
 # Some UDP port
 heartbeat_port=${ENGINE_HEARTBEAT_SERVER_PORT}
-# Seconds how often the vitality of the Engine should be checked (0 = disabled)
-heartbeat_frequency=${ENGINE_HEARTBEAT_FREQUENCY}
 
 [api]
 ## STEERING ##

config/sample.engine.ini

@@ -32,12 +32,12 @@ from_mail="monitoring@aura.engine"
 # A subject prefix allows applying filter rules in your mail client
 mailsubject_prefix="[AURA Engine]"
 
-# Server where heartbeat info is sent to
-heartbeat_server = "127.0.0.1"
+# Seconds how often the vitality of Engine Core should be checked (default=1)
+heartbeat_frequency=1
+# Host where heartbeat is sent to (disabled if empty string)
+heartbeat_server=""
 # Some UDP port
-heartbeat_port = 43334
-# Seconds how often the vitality of the Engine should be checked (0 = disabled)
-heartbeat_frequency = 1
+heartbeat_port=43334
 
 [api]
 ## STEERING ##
@@ -77,11 +77,11 @@ db_pass="---SECRET--PASSWORD---"
 db_host="localhost"
 db_charset="utf8"
 # Base path as seen by "engine-core", not accessed by "engine"; this is required to construct the absolute audio file path (check "Audio Store" in the docs)
-# Either provide an absolute base path or a relative one starting in the `engine-core/src` directory. In case of `engine-core` running in docker use `/var/audio/source`
-audio_source_folder="audio/source"
+# Either provide an absolute base path or a relative one starting in the `engine` directory. In case of `engine-core` running in docker use `/var/audio/source`
+audio_source_folder="../engine-core/audio/source"
 audio_source_extension=".flac"
 # Folder holding M3U Playlists to be scheduled in form of Engine Playlists (similar as audio source folder above)
-audio_playlist_folder="audio/playlist"
+audio_playlist_folder="../engine-core/audio/playlist"
 # Offset in seconds how long it takes for Liquidsoap to actually execute a scheduler command; Crucial to keep things in sync
 engine_latency_offset=0.5
 # How often should the calendar be fetched in seconds. This determines the time of the last changes applied, before a specific show is aired

src/plugins/monitor.py

@@ -262,8 +262,7 @@ class AuraMonitor:
         # After first update start the Heartbeat Monitor
         if not self.heartbeat_running:
             self.heartbeat_running = True
-            if self.config.get("heartbeat_frequency") > 0:
-                self.heartbeat()
+            self.heartbeat()
 
     def heartbeat(self):
         """
@@ -271,19 +270,18 @@ class AuraMonitor:
         a heartbeat is sent to the configured server.
         """
         if self.has_valid_status(True):
-            self.heartbeat_socket.sendto(
-                str.encode("OK"), (self.heartbeat_server, self.heartbeat_port)
-            )
+            # Always check status, but only send heartbeat if wanted so
+            if self.config.get("heartbeat_server") != "":
+                self.heartbeat_socket.sendto(
+                    str.encode("OK"), (self.heartbeat_server, self.heartbeat_port)
+                )
 
             # Engine resurrected into normal state
             if self.already_invalid:
                 self.already_invalid = False
                 status = json.dumps(self.get_status())
-                self.logger.info(
-                    SU.green("OK - Engine turned back into some healthy state!")
-                    + "\n"
-                    + str(status)
-                )
+                msg = SU.green("OK - Engine turned back into some healthy state!")
+                self.logger.info(msg + "\n" + str(status))
                 # Route call of event via event dispatcher to provide ability for additional hooks
                 self.engine.event_dispatcher.on_resurrect(
                     {"engine_id": self.engine_id, "status": status}
@@ -301,7 +299,10 @@ class AuraMonitor:
                     {"engine_id": self.engine_id, "status": status}
                 )
 
-        threading.Timer(self.config.get("heartbeat_frequency"), self.heartbeat).start()
+        heartbeat_frq = self.config.get("heartbeat_frequency", 1)
+        if heartbeat_frq < 1:
+            heartbeat_frq = 1
+        threading.Timer(heartbeat_frq, self.heartbeat).start()
 
     def get_io_state(self):
         """