Generate MySQL metadata file

docker:mysql:generate-metadata

Description

Generate DB metadata file for a given container. This metadata can be used to reconstruct the same container. Metadata includes:

• Original vendor image name (mysql, bitnami/mariadb:10.3, etc.).
• All environment variables from the running container (thus, they include DB name, username, password, etc.).
• Mount destination of the my.cnf file. We need it because it differs between images.
• Actually, a my.cnf file content.
• Target image name to identify where to store the dump.

Supported MySQL images are:

• mysql
• mariadb
• bitnami/mariadb
• Other images based on the above ones

Check for more information: Building MySQL images with DB: how it works

Usage

Example usage:

php bin/dockerizer docker:mysql:generate-metadata <container>

Command arguments

• <container> (first argument): MySQL container name.
• -t (--target-image, optional): Docker image name including registry domain (if needed) and excluding tags. If not specified, the command will ask for it interactively.

There are several ways to supply Docker image name:

• Explicitly pass is via the --target-image option
• Declare it as a Docker container label com.default-value.docker.registry.target-image
• Enter it manually when asked (interactive mode only)

We recommend adding the environment name as a target image suffix, for example: my-docker-registry.com:5000/namespace/repository/database-dev. E.g., add -dev, -staging, -prod to make distinguishing DBs easier.

Required environment variables

Inside a Docker container: MYSQL_USER/MYSQL_PASSWORD/MYSQL_DATABASE or respective MariaDB environment variables. Without them, it will be impossible to generate a new image with the proper credentials.

Metadata file structure

Example metadata file:

{
    "vendor_image": "mysql:8.0.33",
    "environment": [
        "MYSQL_RANDOM_ROOT_PASSWORD=1",
        "MYSQL_DATABASE=project_db",
        "MYSQL_USER=project_user",
        "MYSQL_PASSWORD=q1w2e3r4",
        "affinity:container==somehashgoeshere",
        "PATH=\/usr\/local\/sbin:\/usr\/local\/bin:\/usr\/sbin:\/usr\/bin:\/sbin:\/bin",
        "GOSU_VERSION=1.16",
        "MYSQL_MAJOR=8.0",
        "MYSQL_VERSION=8.0.33-1.el8",
        "MYSQL_SHELL_VERSION=8.0.33-1.el8"
    ],
    "my_cnf_mount_destination": "\/etc\/mysql\/conf.d\/zzz-my.cnf",
    "my_cnf": "[mysqld]\ndatadir=\/var\/lib\/mysql_datadir\n#datadir=\/var\/lib\/mysql_datadir\/\nwait_timeout=28800\nmax_allowed_packet=128M\ninnodb_log_file_size=128M\ninnodb_buffer_pool_size=1G\nlog_bin_trust_function_creators=1\n\n[mysql]\nauto-rehash",
    "target_image": "registry.example.com\/namespace\/project\/database-prod"
}

Called from other commands

• docker:mysql:upload-to-aws
• docker:mysql:test-metadata