connecting to a docker-compose mysql container denies access but docker running same image does not

Question

I am having some issues connecting to the mysql docker container that I have launched with docker-compose. This is a long post (sorry!).

Here is my docker-compose.ym

Answer 1

Environment variables in docker-compose.yml file should not have quotes when using array definition:

db:
  image: mysql:5.7
  ports:
    - "3306:3306"
  environment:
    - MYSQL_ROOT_PASSWORD=secret
    - MYSQL_USER=django
    - MYSQL_PASSWORD=secret
    - MYSQL_DATABASE=myAppDB

---

If you use them in your docker-compose.yml file:

db:
  image: mysql:5.7
  ports:
    - "3306:3306"
  environment:
    - MYSQL_ROOT_PASSWORD="secret"
    - MYSQL_USER="django"
    - MYSQL_PASSWORD="secret"
    - MYSQL_DATABASE="myAppDB"

and run:

$ docker-compose up -d

and enter running container:

$ docker-compose exec db /bin/bash

you will see the output:

root@979813643b0c:/# echo $MYSQL_ROOT_PASSWORD                                                                                                                                              
"secret"