Docker compose: getaddrinfo of mariadb failed

Question

I'm not good at creating docker-compose and am currently having trouble trying to build a new project.

After building, I cannot access the mariadb server in the php application container, I get this error:

PDO::__construct(): php_network_getaddresses: getaddrinfo of mariadb Failure: Name cannot be resolved

So I know something is misconfigured, but I don't know what yet. I tried many changes but nothing worked.

This is my current docker-compose.yml:

version: "3.8"

networks:
  # used by some services (php) to communicate with other docker-compose.yaml
  censored.com:
    external:
      name: censored.com

services:
  app:
    build:
      context: .
      target: symfony_php
      args:
        - secret=id=composerauth,src=${HOME}/.composer/auth.json
    restart: unless-stopped
    healthcheck:
      interval: 10s
      timeout: 3s
      retries: 3
      start_period: 30s
    environment:
      APP_ENV: dev
      HOST: www.censored.lan
    networks:
      - default
      - censored.com
    volumes:
      - ./:/srv/app:rw,cached
      - ./docker/php/conf.d/symfony.dev.ini:/usr/local/etc/php/conf.d/symfony.ini
      - ${HOME}/.composer/auth.json:/root/.composer/auth.json
      # If you develop on Linux, comment out the following volumes to just use bind-mounted project directory from host
      - ./var/cache:/srv/app/cache:rw
      - ./var/log:/srv/app/logs:rw
    depends_on:
      - mariadb

    extra_hosts:
      - www.censored.lan:127.0.0.1

  nginx:
    build:
        context: .
        target: symfony_nginx
        args:
          - secret=id=composerauth,src=${HOME}/.composer/auth.json
    restart: unless-stopped
    depends_on:
      - app
    environment:
      NGINX_DOMAIN: www.censored.lan
    ports:
      - 8001:80
    volumes:
      - ./docker/nginx/templates/dev.conf.template:/etc/nginx/templates/default.conf.template:ro
      - ./docker/nginx/rules/rules.dev.conf:/etc/nginx/rules.conf:ro
      - ./public:/srv/app/public:ro
      - ./src:/srv/app/src:ro

  mariadb:
    image: mariadb:10.7
    environment:
      MYSQL_ROOT_PASSWORD: changeme
      MYSQL_DATABASE: database
      MYSQL_USER: user
      MYSQL_PASSWORD: changeme
    networks:
      - default
      - censored.com
    ports:
      - '3307:3306'
    restart: on-failure
    volumes:
      - db_data:/var/lib/mysql

volumes:
  db_data: {}

Can someone help me solve this problem?

Thanks!

Answer 1

The problem has nothing to do with my docker-compose configuration file.

My application is a PHP Symfony application that does a "cache: clear" after the initial "composer install" during the build. "cache:clear" is triggering a call to a database that is not yet ready. To fix this, I simply set my mariadb version to the "DATABASE_URL" parameter in my Symfony application to avoid useless database queries.