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Percona Software for MySQL Documentation

Docker environment variables

When running a Docker container with Percona Server, you can adjust the configuration of the instance Add one or more environment variables to the docker run command.

These variables will not affect you if you start the container with a data directory that already contains a database. Any pre-existing database remains untouched on the container startup.

The variables are optional, but you must specify at least one of the following:

  • MYSQL_DATABASE - the database schema name that is created when the container starts

  • MYSQL_USER - create a user account when the container starts

  • MYSQL_PASSWORD - used with MYSQL_USER to create a password for that user account.

  • MYSQL_ALLOW_EMPTY_PASSWORD - creates a root user with an empty password. This option is insecure and only should be used for testing or proof of concept when the database can be removed afterward. Anyone can connect as root.

  • MYSQL_ROOT_PASSWORD - this password is used for the root user account. This option is not recommended for production.

  • MYSQL_RANDOM_ROOT_PASSWORD - set this variable instead of MYSQL_ROOT_PASSWORD when you want Percona Server to generate a password for you. The generated password is available in the container’s logs only during the first start of the container. Use docker logs. You cannot retrieve the password after the first start.

To further secure your instance, use the MYSQL_ONETIME_PASSWORD variable.

These variables are visible to anyone able to run Docker inspect. 

$ docker inspect ps
Expected output 
...
 "Env": [
                "MYSQL_ROOT_PASSWORD=root",
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "PS_VERSION=8.4.2-2",
                "OS_VER=el8",
                "FULL_PERCONA_VERSION=8.4.2-2.el8"
               ]
...

You should use Docker secrets or volumes instead.

Percona Server for MySQL also allows adding the _FILE suffix to a variable name. This suffix lets you add the value in a path so that the value cannot be inspected from outside the container.

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Last update: 2023-10-26