Publish robot USB status to MQTT

Follows the status LED

Author: WillB97

runusb/__main__.py

@@ -48,6 +48,8 @@
 # This will be populated if we have the config file
 # url format: mqtt[s]://[<username>[:<password>]@]<host>[:<port>]/<topic_root>
 MQTT_URL = None
+MQTT_TOPIC_ROOT = ''
+MQTT_CLIENT = None
 MQTT_CONFIG_FILE = '/etc/sbot/mqtt.conf'
 
 
@@ -216,6 +218,14 @@ def __init__(self, mountpoint_path: str) -> None:
         self._setup_logging(mountpoint_path)
         LED_CONTROLLER.set_code(True)
         LED_CONTROLLER.set_status(LedStatus.Running)
+        if MQTT_CLIENT is not None:
+            MQTT_CLIENT.publish(
+                f'{MQTT_TOPIC_ROOT}/state',
+                '{"state": "running"}',
+                qos=1,
+                retain=True,
+            )
+
         env = dict(os.environ)
         env["SBOT_METADATA_PATH"] = MOUNTPOINT_DIR
         if MQTT_URL is not None:
@@ -256,6 +266,14 @@ def close(self) -> None:
         LED_CONTROLLER.set_code(False)
         USERCODE_LOGGER.removeHandler(self.handler)
 
+        if MQTT_CLIENT is not None:
+            MQTT_CLIENT.publish(
+                f'{MQTT_TOPIC_ROOT}/state',
+                '{"state": "no USB"}',
+                qos=1,
+                retain=True,
+            )
+
     def _send_signal(self, sig: int) -> None:
         if self.process.poll() is not None:
             # Process has already exited, so the kill() call would fail.
@@ -267,8 +285,18 @@ def _watch_process(self) -> None:
         self.process.wait()
         if self.process.returncode != 0:
             USERCODE_LOGGER.warning(f"Process exited with code {self.process.returncode}")
+            new_state = 'crashed'
         else:
             USERCODE_LOGGER.info("Your code finished successfully.")
+            new_state = 'finished'
+
+        if MQTT_CLIENT is not None:
+            MQTT_CLIENT.publish(
+                f'{MQTT_TOPIC_ROOT}/state',
+                json.dumps({"state": new_state}),
+                qos=1,
+                retain=True,
+            )
 
         process_lifetime = time.time() - self.process_start_time
 
@@ -438,7 +466,7 @@ def read_mqtt_config_file() -> MQTTVariables | None:
 
 
 def setup_usercode_logging() -> None:
-    global REL_TIME_FILTER
+    global REL_TIME_FILTER, MQTT_CLIENT, MQTT_TOPIC_ROOT
     REL_TIME_FILTER = RelativeTimeFilter()
     USERCODE_LOGGER.addFilter(REL_TIME_FILTER)
     USERCODE_LOGGER.setLevel(logging.DEBUG)
@@ -459,6 +487,8 @@ def setup_usercode_logging() -> None:
                 connected_callback=lambda: LED_CONTROLLER.set_wifi(True),
                 disconnected_callback=lambda: LED_CONTROLLER.set_wifi(False),
             )
+            MQTT_CLIENT = handler.mqtt
+            MQTT_TOPIC_ROOT = mqtt_config.topic_prefix
 
             handler.setLevel(logging.INFO)
             handler.setFormatter(TieredFormatter(
@@ -479,6 +509,15 @@ def main():
     registry = AutorunProcessRegistry()
 
     LED_CONTROLLER.mark_start()
+
+    if MQTT_CLIENT is not None:
+        MQTT_CLIENT.publish(
+            f'{MQTT_TOPIC_ROOT}/state',
+            '{"state": "no USB"}',
+            qos=1,
+            retain=True,
+        )
+
     # Initial pass (in case an autorun FS is already mounted)
     registry.update_filesystems(fstab_reader.read())