Docker. MySQL image. Can't change my.cnf file

Question

I have such a docker-compose.yml:

    database:
        container_name: test_db
        image: mysql:5.7
        volumes:
            - ./docker/my.cnf:/etc/my.cnf
        environment:
            - "MYSQL_ROOT_PASSWORD=root"
            - "MYSQL_DATABASE=test_db"
        ports:
            - "3306:3306"
        volumes:
          - test_db_data:/var/lib/mysql

volumes:
    test_db_data:

and I want to edit the sql_mode.

./docker/my.cnf contains:

[mysqld]
sql_mode=""

But when I connect to db from my local machine and run SELECT @@sql_mode; I receive:

ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

What am I doing wrong?

Solution 1

Also I have changed

- ./docker/my.cnf:/etc/my.cnf

to

- ./docker/my.cnf:/etc/alternatives/my.cnf

It's not related to the issue, but looks like it's considered to be a "better practice".

Solution 2

You can add this to your db service:

command: --sql_mode=""

so its:

    database:
    container_name: test_db
    image: mysql:5.7
    volumes:
        - ./docker/my.cnf:/etc/my.cnf
    environment:
        - "MYSQL_ROOT_PASSWORD=root"
        - "MYSQL_DATABASE=test_db"
    ports:
        - "3306:3306"
    volumes:
      - test_db_data:/var/lib/mysql
    command: --sql_mode=""

Solution 3

Try to use only one "volumes" directive. Maybe it uses only the last one.

Comments

[Raghwendra Singh]

Rather than answering your own question and asking a new one in answer, I would suggest editing/updating your question.

[D.R.]

Thank you for the suggestion, but I don't think so. The original issue was Can't change my.cnf file. I have solved it and posted an answer. I don't understand the root of the bug, but I have solved it. If sb can explain it — ok. No — I'm ok with that and don't need a new SO question for that.

[D.R.]

OMG. I have not noticed. I've solved the issue, but the second time it was in one volume "command" (don't know how to name it).

[D.R.]

Interesting idea. Thanks.

[agucho]

@D.R. it worked in my situation, not sure if it will in yours.

[slashdottir]

Please show what the finished docker-compose file looks like? Did you remove the second volumes command?

[D.R.]

@slashdottir sorry, but I don't have it anymore :(

[medina]

For me this was the only approach that worked. Thanks heaps Brad.

[gvanto]

This is a great solution, clean

[Diego Santa Cruz Mendezú]

This worked for me, i agree command: --sql_mode="" and works.