$ docker ps
CONTAINER ID        IMAGE                  COMMAND                  CREATED             STATUS              PORTS                                              NAMES
b02d801f9aa3        development_mongo      "docker-entrypoint.s…"   7 hours ago         Up About an hour    0.0.0.0:50001->27017/tcp                           compose_mongo
2903bb830ea7        development_postgres   "docker-entrypoint.s…"   7 hours ago         Up About an hour    0.0.0.0:50000->5432/tcp                            compose_postgres
6ce3fe015a8f        development_elastic    "/usr/local/bin/dock…"   7 hours ago         Up About an hour    0.0.0.0:50002->9200/tcp, 0.0.0.0:50003->9300/tcp   compose_elastic

$ docker run --name test1 repo/myapp:stage_1605191501

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/dist-packages/django/db/backends/base/base.py", line 217, in ensure_connection
self.connect()
  File "/usr/local/lib/python3.6/dist-packages/django/db/backends/base/base.py", line 195, in connect
self.connection = self.get_new_connection(conn_params)
  File "/usr/local/lib/python3.6/dist-packages/django/db/backends/postgresql/base.py", line 178, in get_new_connection
connection = Database.connect(**conn_params)
  File "/usr/local/lib/python3.6/dist-packages/psycopg2/__init__.py", line 126, in connect
conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: could not connect to server: Connection refused
    Is the server running on host "0.0.0.0" and accepting
    TCP/IP connections on port 50000?

$ docker network inspect development_default | grep 'Name|IPv4'
    "Name": "development_default",
            "Name": "compose_postgres",
            "IPv4Address": "172.20.0.2/16",
            "Name": "compose_elastic",
            "IPv4Address": "172.20.0.4/16",
            "Name": "compose_mongo",
            "IPv4Address": "172.20.0.3/16",