Using docker-compose in order to create a MySQL schema/database

Question

I am trying to create a mysql database/schema if it doesn't already exist.

Here is what I have tried:

docker-compose.yml

mysql:
  image: mysql:5.6.26
  environment:
   - MYSQL_ROOT_PASSWORD=root
  command: "mysql -uroot -proot < createDB.sql"
  ports:
    - "3306:3306"

createDB.sql

CREATE DATABASE IF NOT EXISTS bignibou;

It does not work. What would be the best way to use docker/docker-compose in order to create a schema if it does not exist?

Answer 1

I finally found the beginning of a solution.

The MySQL image takes an environment variable i.e. MYSQL_DATABASE that initialize the container with the name of the database on image startup See here for full documentation.

Or read the excerpt below:

MYSQL_DATABASE

This variable is optional and allows you to specify the name of a database to be created on image startup. If a user/password was supplied (see below) then that user will be granted superuser access (corresponding to GRANT ALL) to this database.

Here is what I came up with:

mysql:
  image: mysql:5.6.26
  environment:
   - MYSQL_ROOT_PASSWORD=root
   - MYSQL_DATABASE=bignibou
  ports:
    - "3306:3306"

I now need a way to specify the default collation but that is another story...

edit: For those interested in specifying a different collation from the default, here are the instructions to use another config file that will override the default one. See below:

Using a custom MySQL configuration file The MySQL startup configuration is specified in the file /etc/mysql/my.cnf, and that file in turn includes any files found in the /etc/mysql/conf.d directory that end with .cnf. Settings in files in this directory will augment and/or override settings in /etc/mysql/my.cnf. If you want to use a customized MySQL configuration, you can create your alternative configuration file in a directory on the host machine and then mount that directory location as /etc/mysql/conf.d inside the mysql container.

If /my/custom/config-file.cnf is the path and name of your custom configuration file, you can start your mysql container like this (note that only the directory path of the custom config file is used in this command):

$ docker run --name some-mysql -v /my/custom:/etc/mysql/conf.d -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:tag This will start a new container some-mysql where the MySQL instance uses the combined startup settings from /etc/mysql/my.cnf and /etc/mysql/conf.d/config-file.cnf, with settings from the latter taking precedence.

Answer 2

To not lost your data better use volumes as well:

version: '3'
services:
  db:
    image: mysql:5.7
    volumes:
        - mysql-db:/var/lib/mysql
    environment:
        MYSQL_ROOT_PASSWORD: root
        MYSQL_DATABASE: my_db_name
    ports:
        - "3307:3306"
volumes:
  mysql-db: