Use nginx-proxy and v3.7.1 (Docker)

Just want to describe my setup to run Mattermost using the Docker setup together with nginx-proxy in front of Mattermost. Since v3.7.1 the Mattermost Docker setup creates it's own network for communication between containers. nginx-proxy needs to know about this network. That means you need to find the network and connect it to nginx-proxy:

docker network ls
# Grep the name of your Mattermost network like "mymattermost_default".
docker network connect mymattermost_default nginx-proxy

Now restart the Mattermost app container (or web if using it) to get nginx-proxy configured correctly:

docker-compose stop app
docker-compose start app

BTW: With nginx-proxy there is no need to run the web container. My docker-compose.yml looks like this:

version: "2"

services:

  db:
    build: db
    restart: unless-stopped
    volumes:
      - ./volumes/db/var/lib/postgresql/data:/var/lib/postgresql/data
      - /etc/localtime:/etc/localtime:ro
    environment:
      - POSTGRES_USER=mmuser
      - POSTGRES_PASSWORD=mmuser_password
      - POSTGRES_DB=mattermost
    # uncomment the following to enable backup
    #  - AWS_ACCESS_KEY_ID=XXXX
    #  - AWS_SECRET_ACCESS_KEY=XXXX
    #  - WALE_S3_PREFIX=s3://BUCKET_NAME/PATH
    #  - AWS_REGION=us-east-1
    #  in case your config is not in default location
    #  - MM_CONFIG=/mattermost/config/config.jso

  app:
    build:
      context: app
      # comment out for team edition
      #dockerfile: Dockerfile-enterprise
    restart: unless-stopped
    volumes:
      - ./volumes/app/mattermost/config:/mattermost/config:rw
      - ./volumes/app/mattermost/data:/mattermost/data:rw
      - ./volumes/app/mattermost/logs:/mattermost/logs:rw
      - /etc/localtime:/etc/localtime:ro
    environment:
      # set same as db credentials and dbname
      - MM_USERNAME=mmuser
      - MM_PASSWORD=mmuser_password
      - MM_DBNAME=mattermost
      - VIRTUAL_HOST=mymattermost.tld
      - LETSENCRYPT_HOST=mymattermost.tld
      - LETSENCRYPT_EMAIL=me@mymattermost.tld
    expose:
     - "80"
    depends_on:
      - db

Notes:

• Important changes are the VIRTUAL_HOST environment variable and the expose directive which tells nginx-proxy where to connect to the Mattermost backend.
• I'm using the LetsEncrypt companion container for nginx-proxy for automatic Let's Encrypt certs.
• You may customize the nginx-proxy settings as described at their Github page (can not post the link because as new user to this forum I'm not allowed to post mor than 2 links). For instance the Mattermost nginx is configured with client_max_body_size 50M;.
• The network needs to be connected manually this way. To automatize this you may create a independent network before and use it together with nginx-proxy. See docker-compose documentation regarding using external networks.