Docker nginx proxy works with docker-compose v1, but not v2?

Question

I'm trying to setup an nginx proxy for my docker containers to use simple subdomains instead of ports. I like using docker-compose to startup my containers and since I'm quite new to docker in general, I started using v2 format right away.

I've spend quite some time figuring out why this very popular and seemingly simple to use nginx proxy container did not work for me. It turned out that it is somehow related to my use of docker-compose v2.

I will post the docker-compose.yml files I was using first, which did not work for some reason:

version: '2'

services:
  nginx-proxy:
    image: jwilder/nginx-proxy:alpine
    container_name: nginx-proxy
    network_mode: bridge
    ports:
      - 80:80
      - 443:443
    volumes:
      - /var/run/docker.sock:/tmp/docker.sock:ro
    environment:
      - ENABLE_IPV6=true
      - DEFAULT_HOST=domain.com

  whoami:
    image: jwilder/whoami
    network_mode: bridge
    environment:
      - VIRTUAL_HOST=whoami.local

And this is the example Jenkins container to test it:

version: "2"

services:
  jenkins:
    image: jenkins:2.46.2-alpine
    restart: always
    hostname: jenkins.domain.com
    network_mode: bridge
    expose:
      - 8080
      - 50000
    ports:
      - 8080:8080
      - 50000:50000
    volumes:
      - /srv/jenkins:/var/jenkins_home
    environment:
      - VIRTUAL_HOST=jenkins.domain.com
      - VIRTUAL_PORT=8080

Now I will post the configuration which actually did work out of the box for me:

nginx-proxy:
  image: jwilder/nginx-proxy:alpine
  container_name: nginx-proxy
  ports:
    - 80:80
    - 443:443
  volumes:
    - /var/run/docker.sock:/tmp/docker.sock:ro
  environment:
    - ENABLE_IPV6=true
    - DEFAULT_HOST=domain.com

whoami:
  image: jwilder/whoami
  environment:
    - VIRTUAL_HOST=whoami.local

And for the Jenkins container:

jenkins:
  image: jenkins:2.46.2-alpine
  restart: always
  hostname: jenkins.domain.com
  expose:
    - 8080
    - 50000
  ports:
    - 8080:8080
    - 50000:50000
  volumes:
    - /srv/jenkins:/var/jenkins_home
  environment:
    - VIRTUAL_HOST=jenkins.domain.com
    - VIRTUAL_PORT=8080

The only real difference I see is the removal of network_mode: bridge. I've added that when I noticed that with v2 there are seperate networks being created, but with v1 (or a simple docker run), they end up on the same network. Using network_mode: bridge seemed to solve this issue.

Besides this, it's only a structural change in the docker-compose.yml files, but there must be some other differences which stop this setup from working.

Since V1 is deprecated and I would like to use v2 format... what do I have to change to make docker-compose v2 act like v1 and get the proxy to work correctly?

Answer 1

You need to make sure the containers are on the same network. In nginx-proxy, it won't add an upstream setting if it can't reach the node. You should see something like:

$ docker exec -it nginx-proxy cat /etc/nginx/conf.d/default.conf
# ....
# whoami.local
upstream whoami.local {
                                ## Can be connect with "nginxproxy_default" network
                        # nginxproxy_whoami_1
                        server 172.19.0.3:8000;
}
# ....

If that upstream section is empty, without the comments and server line, then it's unable to find a common docker network to reach the container and it won't be able to route traffic.

I'm seeing that with the following compose file:

version: '2'

services:
  nginx-proxy:
    image: jwilder/nginx-proxy:alpine
    container_name: nginx-proxy
    ports:
      - 8080:80
      - 8443:443
    volumes:
      - /var/run/docker.sock:/tmp/docker.sock:ro
    environment:
      - ENABLE_IPV6=true
      - DEFAULT_HOST=domain.com

  whoami:
    image: jwilder/whoami
    environment:
      - VIRTUAL_HOST=whoami.local

And I can verify it with:

$ curl -H "Host: whoami.local" http://localhost:8080
I'm b066afdb6e45

With Jenkins, when you spin that up with a separate compose file (actually a separate compose project which happens by default when your in a different directory name), it will get a separate default network. The easiest solution I have is to use an external network. First you create it directly in docker:

$ docker network create proxynet

And then your compose file would include that external network:

version: '2'

networks:
  proxynet:
    external: true

services:
  nginx-proxy:
    image: jwilder/nginx-proxy:alpine
    container_name: nginx-proxy
    ports:
      - 8080:80
      - 8443:443
    volumes:
      - /var/run/docker.sock:/tmp/docker.sock:ro
    networks:
      - proxynet
    environment:
      - ENABLE_IPV6=true
      - DEFAULT_HOST=domain.com

  whoami:
    image: jwilder/whoami
    environment:
      - VIRTUAL_HOST=whoami.local
    networks:
      - proxynet

You would do the same with Jenkins:

version: "2"

networks:
  proxynet:
    external: true

services:
  jenkins:
    image: jenkins:2.46.2-alpine
    restart: always
    hostname: jenkins.domain.com
    networks:
      - proxynet
    expose:
      - 8080
      - 50000
    ports:
      - 8080:8080
      - 50000:50000
    volumes:
      - /srv/jenkins:/var/jenkins_home
    environment:
      - VIRTUAL_HOST=jenkins.domain.com
      - VIRTUAL_PORT=8080