Can't connect mysql docker to Drupal docker - mysql

Question

I'm following the instructions here https://hub.docker.com/_/drupal
I ran $ docker run --name some-drupal -d drupal just fine
and I ran
`docker run -d --name some-mysql --network some-network \
-e MYSQL_DATABASE=drupal \
-e MYSQL_USER=user \
-e MYSQL_PASSWORD=password \
-e MYSQL_ROOT_PASSWORD=password \
mysql:5.7`
just fine as well. But when I go through the drupal install script in the browser, when I get to the database connection. The connection throughs an error. I've tried user as the user and root as the user, either way I get this same error. Not sure if I need to connect more ports to the containers but The instruction make it sound like this should work. What am I missing?

Answer 1

Docker can only resolve containers hostname to each other when they are on the same custom network.
Your mysql container are in network some-network as you show here:
docker run -d --name some-mysql --network some-network ...
When you start the drupal container you'll need to do the same:
docker run --name some-drupal -d --network some-network drupal

Answer 2

I recommend using docker-compose.yml file with Dockerfileif needed.
For example, this is the contents of docker-file.yml:
version: '3.9'
services:
SOME_DRUPAL_NAME:
image: drupal
restart: always
ports:
- 80:80
- 443:80
depends_on:
SOME_MYSQL_NAME
environment:
SOME_VARS: SOME_VALUE
SOME_MYSQL_NAME:
image: mysql
restart: always
environment:
MYSQL_ROOT_PASSWORD: somedrupal
MYSQL_DATABASE: drupal
MYSQL_USER: drupal
MYSQL_PASSWORD: drupal
networks:
default:
external:
name: SOME_NETWORK_NAME
volumes:
SOME_NAME: {}
After having this file edited, run this command:
docker network create SOME_NETWORK_NAME
Also see Drupal environment variables for connecting Drupal to MySQL to add in docker-compose.yml file.
At last and when all things are done, run this:
docker-compose -f /to/your/docker-compose/file/docker-compose.yml up -d
Or if you're in the same path as docker-compose.yml:
docker-compose up -d
Then it should work.