Preview deployments with docker compose: how to connect between containers?

[hydrandt]

I have an app that consists of three containers: django backend, mysql database, react frontend. I could deploy it using this docker compose file:

services:

  db:
    image: mysql:latest
    volumes:
      - db-data:/var/lib/mysql

  django:
    build:
      context: .
      dockerfile: ./docker/django/Dockerfile
      ...
    volumes:
      - .:/code
    depends_on:
      - db

  frontend:
    build:
      context: .
      dockerfile: ./docker/frontend/Dockerfile
      target: ...
    volumes:
      - .:/node_app/code
    depends_on:
      - django

  nginx:
    image: nginx:latest
    volumes:
      - ./docker/nginx/nginx.coolify.conf:/etc/nginx/nginx.conf:ro
    depends_on:
      - frontend
      - django

This works fine for the "normal deployment". However, I am mostly interested to use the "Preview deployment" functionality. When I manually deploy a pull request now, the docker compose file that is generated changes the container names (db-pr-295, frontend-pr-295 etc.). This breaks the connection to the database, and nginx config, as it relies on the original container names.

What would be the recommended way to go forward here? What I could think of:

1. Use a separately deployed mysql; get rid of the nginx container

• deploy a database instance inside the project
• then use the Pre Deployment Commands function to create a new database, using the environment variable that coolify can generate for docker compose projects (SERVICE_USER_DB and SERVICE_PASSWORD_DB should work?)
• instead of having the nginx reverse proxy, use the "Domains" config space and configure something like this: https://{{pr_id}}.coolify.project.com:9000/api, https://{{pr_id}}.coolify.project.com:9000/admin, https://{{pr_id}}.coolify.project.com:9000/api, https://{{pr_id}}.coolify.project.com:9000/admin. ...)
  • Problem: I tried this, but the /api, /admin etc. get stripped from the path, so the route is wrong; I suppose it should be possible to configure this behavior?

2. Use the COOLIFY_BRANCH env var to construct other containers name

In django configuration code, and after starting the nginx container using envsubst, detect that we are not on the "main" branch, and in that case, construct the hostnames of other containers from the COOLIFY_BRANCH env var.

That's quite hacky.

3. Some other way?

Is there another preferred way to do this?

For the sake of completeness, this is the nginx config:

http {
  upstream django {
    server django:9000; 
  }
  upstream frontend {
    server frontend:80;
  }

  server {
    listen 80;

    location / {
      proxy_pass http://frontend;
      proxy_set_header Host $http_host;
      proxy_set_header X-Real-IP $remote_addr;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header X-Forwarded-Proto $scheme;
    }

    location ~ ^/(api|qadmin|validate_token|confirm|static) {
      proxy_pass http://django;
      proxy_set_header Host $http_host;
      proxy_set_header X-Real-IP $remote_addr;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header X-Forwarded-Proto $scheme;
    }
  }
}

[tm1000]

Seems to be an ongoing issue: #3511