Docker Official Image Frequently Asked Questions

Frequently asked questions about the Docker Official Image

How to Reset Passwords

If you have an existing data directory and wish to reset the root and user passwords, and to create a database which the user can fully modify, perform the following steps.

First create a `passwordreset.sql` file:

CREATE USER IF NOT EXISTS root@localhost IDENTIFIED BY 'thisismyrootpassword';
SET PASSWORD FOR root@localhost = PASSWORD('thisismyrootpassword');
GRANT ALL ON *.* TO root@localhost WITH GRANT OPTION;
GRANT PROXY ON ''@'%' ON root@localhost WITH GRANT OPTION;
CREATE USER IF NOT EXISTS root@'%' IDENTIFIED BY 'thisismyrootpassword';
SET PASSWORD FOR root@'%' = PASSWORD('thisismyrootpassword');
GRANT ALL ON *.* TO root@'%' WITH GRANT OPTION;
GRANT PROXY ON ''@'%' ON root@'%' WITH GRANT OPTION;
CREATE USER IF NOT EXISTS myuser@'%' IDENTIFIED BY 'thisismyuserpassword';
SET PASSWORD FOR myuser@'%' = PASSWORD('thisismyuserpassword');
CREATE DATABASE IF NOT EXISTS databasename;
GRANT ALL ON databasename.* TO myuser@'%';

Adjust `myuser`, `databasename` and passwords as needed.

Then:

$ docker run --rm -v /my/own/datadir:/var/lib/mysql -v /my/own/passwordreset.sql:/passwordreset.sql:z %%IMAGE%%:latest --init-file=/passwordreset.sql

On restarting the MariaDB container in this `/my/own/datadir`, the `root` and `myuser` passwords will be reset.

Temp Server Start Timeout

Question, are you getting errors like the following where a temporary server start fails to succeed in 30 seconds?

Example of log:

2023-01-28 12:53:42+00:00 [Note] [Entrypoint]: Starting temporary server
2023-01-28 12:53:42+00:00 [Note] [Entrypoint]: Waiting for server startup
2023-01-28 12:53:42 0 [Note] mariadbd (server 10.10.2-MariaDB-1:10.10.2+maria~ubu2204) starting as process 72 ...
....
2023-01-28 12:53:42 0 [Note] InnoDB: Setting file './ibtmp1' size to 12.000MiB. Physically writing the file full; Please wait ...
2023-01-28 12:54:13 0 [Note] mariadbd: ready for connections.
Version: '10.10.2-MariaDB-1:10.10.2+maria~ubu2204'  socket: '/run/mysqld/mysqld.sock'  port: 0  mariadb.org binary distribution
2023-01-28 12:54:13+00:00 [ERROR] [Entrypoint]: Unable to start server.

The timeout on a temporary server start is a quite generous 30 seconds.

The lack of a message like the following indicates it failed to complete writing a temporary file of 12MiB in 30 seconds.

2023-01-28 12:53:46 0 [Note] InnoDB: File './ibtmp1' size is now 12.000MiB.

If the datadir where this is stored is remote storage maybe it's a bit slow. It's ideal to have an InnoDB temporary path local so this can be configured using the command or configuration setting:

innodb_temp_data_file_path=/dev/shm/ibtmp1:12M:autoextend

Note: depending on container runtime this space may be limited.

Creating a replication pair

`MARIADB_REPLICATION_USER` / `MARIADB_REPLICATION_PASSWORD` specify the authentication for the connection. The `MARIADB_MASTER_HOST` is the indicator that it is a replica and specifies the container aka hostname, of the master.

A `docker-compose.yml` example: <<code>> version: "3" services: master: image: mariadb:latest command: --log-bin --log-basename=mariadb environment: - MARIADB_ROOT_PASSWORD=password - MARIADB_USER=testuser - MARIADB_PASSWORD=password - MARIADB_DATABASE=testdb - MARIADB_REPLICATION_USER=repl - MARIADB_REPLICATION_PASSWORD=replicationpass healthcheck: test: ["CMD", "healthcheck.sh", "--connect", "--innodb_initialized"] interval: 10s timeout: 5s retries: 3 replica: image: mariadb:latest command: --server-id=2 --log-basename=mariadb environment: - MARIADB_ROOT_PASSWORD=password - MARIADB_MASTER_HOST=master - MARIADB_REPLICATION_USER=repl - MARIADB_REPLICATION_PASSWORD=replicationpass - MARIADB_HEALTHCHECK_GRANTS=REPLICA MONITOR healthcheck: test: ["CMD", "healthcheck.sh", "--connect", "--replication_io", "--replication_sql", "--replication_seconds_behind_master=1", "--replication"] interval: 10s timeout: 5s retries: 3 depends_on: master: condition: service_healthy <<code>>