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

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:

Answer 3

probably what you are trying to do needs an additional script. So if building an image instead of directly using a prebuilt image is an option for you, you need to use a Dockerfile and use a script file which first imports the script in MySql and then runs the service itself.
take a look at this answer: Docker - Initialize mysql database with schema

Answer 4

From the docker-compose documentation - see Define Services - you can tell which Dockerfile it will use to build the image. Therefore you can create a Dockerfile based on the mysql image and create the database inside it using standard Dockerfile commands.

Answer 5

This might be useful in case someone lands here in future. The real issue appears to be the "command" statement in the docker-compose file. Once the command finishes successfully the container will get destroyed. This sql script must be run only after docker-compose has run and containers have been created. docker-compose "command" is really to start a service in the container. In this case you overrode the mysql service with your command.