mysql connection closed when using docker

Question

I am facing a problem when I am trying to connect to mysql using docker.

My docker-compose file

version: '2'
services:
  app:
    build:
      context: ./docker/app
      dockerfile: Dockerfile
    image: ebdaa-m.test.com/app
    volumes:
     - .:/var/www/html
    ports:
     - "80:80"
    networks:
     - sdnet
  node:
    build:
      context: ./docker/node
      dockerfile: Dockerfile
    image: ebdaa-m.test.com/node
    volumes:
     - .:/var/www/html
    networks:
     - sdnet
  mysql:
    image: mariadb:10.5
    ports:
     - "3306:3306"
    environment:
      MYSQL_ROOT_PASSWORD: "root"
      MYSQL_DATABASE: "ecom"
      MYSQL_USER: "root"
      MYSQL_PASSWORD: "root"
    volumes:
     - mysqldata:/var/lib/mysql
    networks:
     - sdnet
  redis:
    image: redis:alpine
    volumes:
     - redisdata:/data
    networks:
     - sdnet
networks:
  sdnet:
    driver: "bridge"
volumes:
  mysqldata:
    driver: "local"
  redisdata:
    driver: "local"

Now when I compose this the container gets created. My docker ps -a command gives me the following result

CONTAINER ID   IMAGE                   COMMAND                  CREATED         STATUS                     PORTS                    NAMES
5c925d3610c0   ebdaa-m.test.com/node   "node"                   2 minutes ago   Exited (0) 2 minutes ago                            ebdaa-m-node-1
d001ed99afa4   mariadb:10.5            "docker-entrypoint.s…"   2 minutes ago   Up 2 minutes               0.0.0.0:3306->3306/tcp   ebdaa-m-mysql-1
7f86bd9a006c   ebdaa-m.test.com/app    "/usr/bin/supervisord"   2 minutes ago   Up 2 minutes               0.0.0.0:80->80/tcp       ebdaa-m-app-1
354b5ae00e39   redis:alpine            "docker-entrypoint.s…"   2 minutes ago   Up 2 minutes               6379/tcp                 ebdaa-m-redis-1

Now When I am trying to connect to the mysql using sequel pro. I am passing the following credentials to connect

Host: 127.0.0.1
User: root
Password: root
Port: 3306

I get the following error when I try to establish a connection -:

Lost connection to MySQL server at 'reading initial communication packet', system error: 0 (2013)

Double-check the MySQL host and port settings are correct, the server is running, and that no firewall settings are blocking access to the server.

If you are connecting through an SSH tunnel, the MySQL host should be the correct address relative to the machine you're SSHing into. Using, for example, the external IP for the MySQL host rather than the local one can often be a source of problems.

Please assist. I am not able to understand what could be the issue as it was working fine before.

Thank you in advance.

user_4222206 · Answer

You claim "it was working fine before". What happened in the meantime?

What you can do as checks is to find out if a process is listening to port 3306:

netstat -lanp | grep :3306

If the output is empty go back and check your container as nothing is listening on that port.
If the output contains 127.0.0.1 or "any wildcard of IP" try the connection again
If the connection contains a specific IP which is not 127.0.0.1, use that IP to connect.

You may also want to check whether the version of mariadb you are running inside the container and the version of the mariadb client outside of the container have compatible versions.

mysql connection closed when using docker

1 Answers