Support sharing Docker audio with host

Dockerfile

@@ -3,8 +3,13 @@ ARG TYPE=development
 
 FROM edwardbrown/python as base
 ENV DEBIAN_FRONTEND=noninteractive
+
+RUN useradd --uid 1000 --create-home amniotic
+
 RUN apt -qq update -y
-RUN apt -qq install -y pulseaudio vlc
+RUN apt -qq install -y pulseaudio vlc alsa-utils
+
+COPY amniotic.client.conf /amniotic.client.conf
 
 FROM base AS development
 WORKDIR /usr/src

amniotic.client.conf

@@ -0,0 +1,6 @@
+default-server = unix:/amniotic.socket
+# Prevent a server running in the container
+autospawn = no
+daemon-binary = /bin/true
+# Prevent the use of shared memory
+enable-shm = false

amniotic/mqtt/loop.py

@@ -1,4 +1,5 @@
 from json import JSONDecodeError
+from pathlib import Path
 from time import sleep
 
 import json
@@ -73,7 +74,15 @@ def __init__(self, config: Config, device: Device, amniotic: Amniotic):
         if config.mqtt_username is not None and config.mqtt_password is not None:
             self.client.username_pw_set(username=config.mqtt_username, password=config.mqtt_password)
 
-        self.client.connect(host=config.mqtt_host, port=config.mqtt_port)
+        msg = f'Attempting to connect to MQTT "{config.mqtt_host}:{config.mqtt_port}"...'
+        logging.info(msg)
+
+        try:
+            self.client.connect(host=config.mqtt_host, port=config.mqtt_port)
+        except Exception as exception:
+            msg = f'Error connecting. This usually means your MQTT host is not available.'
+            raise ConnectionError(msg) from exception
+
 
     def on_message(self, client: mqtt.Client, amniotic: Amniotic, mqtt_message: mqtt.MQTTMessage):
         """
@@ -300,8 +309,4 @@ def start():
         amniotic=amniotic,
     )
 
-    loop.loop_start()
-
-
-if __name__ == '__main__':
-    start()
+    loop.loop_start()

amniotic/mqtt/start.py

@@ -0,0 +1,22 @@
+from pathlib import Path
+import logging
+
+def start():
+
+    path_socket=Path('/amniotic.socket')
+
+    if path_socket.exists():
+        msg=f'Pulse socket found at "{path_socket}". Using host-shared audio.'
+        logging.info(msg)
+        import os
+        os.environ['PULSE_SERVER'] = "unix://amniotic.socket"
+        os.environ['PULSE_COOKIE'] = "/amniotic.cookie"
+    else:
+        msg = f'No Pulse socket found at "{path_socket}". Using dedicated audio.'
+        logging.warning(msg)
+
+    from amniotic.mqtt import loop
+    loop.start()
+
+if __name__ == '__main__':
+    start()

setup.py

@@ -39,7 +39,7 @@
     },
     entry_points={
         'console_scripts': [
-            'amniotic = amniotic.mqtt.loop:start',
+            'amniotic = amniotic.mqtt.start:start',
         ],
     }
 )