enable support for specifying port

docker-compose.yml.example

@@ -7,6 +7,8 @@ services:
     container_name: microblogpub
     user: 1000:1000
     restart: always
+    environment:
+      APP_PORT: 8000
     networks:
       - nproxy
     volumes:

misc/docker-supervisord.conf

@@ -5,7 +5,7 @@ logfile_maxbytes=0
 pidfile=data/supervisord.pid
 
 [program:uvicorn]
-command=uvicorn app.main:app --no-server-header --host 0.0.0.0
+command=uvicorn app.main:app --no-server-header --host 0.0.0.0 --port %(ENV_APP_PORT)s
 numprocs=1
 autorestart=true
 redirect_stderr=true