Add initial coturn server

compose.yml

@@ -5,7 +5,7 @@ services:
   synapse:
     image: "matrixdotorg/synapse:latest"
     volumes:
-      - "data:/data"
+      - "synapse:/data"
     environment:
       - VIRTUAL_HOST=${DOMAIN}
       - VIRTUAL_PORT=8008
@@ -32,13 +32,25 @@ services:
         target: /docker-entrypoint.sh
         mode: 0555
 
+  coturn:
+    image: instrumentisto/coturn:latest
+    networks:
+     - swarm_host
+
 volumes:
-  data:
+  synapse:
+  traefik_letsencrypt:
+    external: true
 
 networks:
   proxy:
     external: true
   internal:
+  # use host-mode networking until Docker can handle mass port-forwards:
+  # https://github.com/moby/moby/issues/11185
+  swarm_host:
+    external:
+      name: 'host'
 
 configs:
   entrypoint_conf: