How to access another port container?

[edikurniawan-dev]

I created an application and have a simple docker compose configuration below.

services:
  php:
    build: .
    ports:
      - "8080:80"
    volumes:
      - .:/var/www/html
    depends_on:
      - db

  db:
    image: mysql:5.7
    environment:
      MYSQL_ROOT_PASSWORD: ${DB_ROOT_PASSWORD}
      MYSQL_DATABASE: ${DB_NAME}
      MYSQL_USER: ${DB_USER}
      MYSQL_PASSWORD: ${DB_PASSWORD}
    volumes:
      - mysql_data:/var/lib/mysql
    ports:
      - "3306:3306"

  phpmyadmin:
    image: phpmyadmin/phpmyadmin
    ports:
      - "8081:81"
    environment:
      APACHE_PORT: 81
      PMA_HOST: db
      MYSQL_ROOT_PASSWORD: ${DB_ROOT_PASSWORD}
    depends_on:
      - db

volumes:
  mysql_data:

I added the domain web.domain.com with port 80 and web-pma.domain.com with port 81.
When I access web.domain.com, it works fine and displays the main website, but I can't access web-pma.domain.com with a bad gateway message. How can I access phpMyAdmin?

[dosubot[bot]]

Hi @edikurniawan-dev! I'm Dosu and I’m helping the dokploy team.

The issue is with your Docker Compose configuration. In Dokploy, you should use expose instead of ports — Dokploy's internal reverse proxy handles the routing, so host port mappings create conflicts.

Here's how to fix it:

1. Update your docker-compose.yml:

services:
  php:
    build: .
    expose:
      - "80"
    volumes:
      - .:/var/www/html
    depends_on:
      - db

  db:
    image: mysql:5.7
    environment:
      MYSQL_ROOT_PASSWORD: ${DB_ROOT_PASSWORD}
      MYSQL_DATABASE: ${DB_NAME}
      MYSQL_USER: ${DB_USER}
      MYSQL_PASSWORD: ${DB_PASSWORD}
    volumes:
      - mysql_data:/var/lib/mysql

  phpmyadmin:
    image: phpmyadmin/phpmyadmin
    expose:
      - "80"
    environment:
      PMA_HOST: db
      MYSQL_ROOT_PASSWORD: ${DB_ROOT_PASSWORD}
    depends_on:
      - db

volumes:
  mysql_data:

2. Configure domains in Dokploy:

• For web.domain.com: set the service to php and port to 80
• For web-pma.domain.com: set the service to phpmyadmin and port to 80

Note that phpMyAdmin's default image listens on port 80, not 81 (unless you specifically configure APACHE_PORT). Since Dokploy manages the external routing, you don't need to change Apache's port — just expose port 80 and let Dokploy route web-pma.domain.com to the phpmyadmin service on port 80.

To reply, just mention @dosu.

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[naturedamends]

Idk, but try rebuilding deploying to refresh the reverse proxy config? Im a noob so idk, it worked for me once

[edikurniawan-dev]

I'm also a noob at this.
Thanks for the advice, but I've already tried that and I'm still getting a Bad Gateway error on the phpMyAdmin domain.

[naturedamends]

The bad gateway suggests its hitting your instance. And dns has resolved. But traffic is not routing it the container.

The port should be exposed in the container.

So a guess would be the Host header to container mapping.

I have not used the traffic auto generate sub domains.
But is possible its routing something like

servicename.web.example.com to pma
Or even, pma.web.example.com.example.com

Appending it to the main domain

Is your domain dns routing wildcard to your instanse.

Can you access the port from remote or even on the hosts localhost:3636 or whatever

I got Dokploy/website#145 working woth the dns resolving to the host ip . Then specifying a full domain in the service. No sub domain generating

Baszel.local to ip to container
gitea.local