Install and Run MariaDB as a Docker Container

Welcome to our basic tutorial on how to install and run MariaDB as a Docker container. According to Docker website, “Docker is an open platform for developing, shipping, and running applications“. A container on the hand “is a standard unit of software that packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another. A Docker container image is a lightweight, standalone, executable package of software that includes everything needed to run an application: code, runtime, system tools, system libraries and settings“.

Installing MariaDB as a Docker Container

Install Docker Engine

Before you can proceed, install Docker Engine on your system. Follow the links below to install Docker Engine on CentOS 8/Ubuntu 20.04 systems;

Install and Use Docker CE on CentOS 8

Install Docker CE on Ubuntu 20.04

Download MariaDB Docker Image

Every docker container is based off a specific image. Docker image contains everything that is necessary to run a container and is therefore a series of instructions that defines how an application is run.

You can build your own Docker image or simply utilize the images that the community have created. You can find the images at the Docker Hub.

In this tutorial, we will be utilizing the community available Docker images.

Search for MariaDB Docker Image

First off, you need to identify the name of the specific MariaDB Docker Image. To search for the image on the docker hub, simply run the command below;

docker search mariadb

You will get a ton of MariaDB images that have been created;

NAME                                   DESCRIPTION                                     STARS               OFFICIAL            AUTOMATED
mariadb                                MariaDB is a community-developed fork of MyS…   3572                [OK]                
linuxserver/mariadb                    A Mariadb container, brought to you by Linux…   151                                     
bitnami/mariadb                        Bitnami MariaDB Docker Image                    120                                     [OK]
toughiq/mariadb-cluster                Dockerized Automated MariaDB Galera Cluster …   41                                      [OK]
...

Usually, an image with no prefix is considered official docker hub image, stable and being maintained. It also contains [OK] on the Official column. Therefore, we will pull the first image from the list above.

Download MariaDB Docker Image from Docker Hub

To download the Docker Image, you use the docker pull <name-of-the-image> command. In this case, our image name is mariadb.

docker pull mariadb

The command downloads the image to your system, if doesn’t already exist.

By default, when you pull a docker image, the latest version of it is downloaded. If you need to download other versions of MariaDB Docker Images, for example, MariaDB 10.3 Docker Image, simply use the command;

docker pull mariadb:10.3

You can see a wide range of tags you can use on Docker Hub MariaDB page.

List Downloaded Docker Images

You can list locally available images using the docker images command.

docker images

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
mariadb             latest              8075b7694a2d        8 days ago          407MB

We have the latest MariaDB Docker Image downloaded.

Running MariaDB Docker Container

Once you have the Docker image in place, you can then create and run a docker container based on the image. docker run <options> <image-name> is the Docker command for running Docker containers.

When running a MariaDB container, you need to specify one of following environment variables:

• MYSQL_ROOT_PASSWORD: specifies the password that will be set for the MariaDB root (mandatory).
• MYSQL_ALLOW_EMPTY_PASSWORD: sets an empty password for MariaDB root user account (optional). Takes the values, yes or no
• MYSQL_RANDOM_ROOT_PASSWORD: Sets a random password for MariaDB root user account (optional). Takes the values, yes or no

In our case here, the name of the image is, mariadb (with latest being the tag);

docker run --name mariadbdemo -e MYSQL_ROOT_PASSWORD=password -d mariadb

The command above basically creates and run (in the background, -d) the MariaDB Docker container based on the latest image version available, sets the MariaDB database root password to password (-e MYSQL_ROOT_PASSWORD=password) and the name of the container as mariadbdemo (--name mariadbdemo, random names are usually set for containers if you don’t specify the name).

If you have other versions of MariaDB Docker Images, you can specify the tags to run a container based on that specific image. For example, assuming we had MariaDB 10.4 image and we would like to run a container based on that image, you could specify the tag as, mariadb:10.4.

 docker run --name mariadbdemo -d -e MYSQL_ROOT_PASSWORD=password mariadb:10.4

Check docker run --help for more options.

List Running Containers

Once you have run a container, you can list them using the docker ps command.

docker ps

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES
ce03099cfffa        mariadb             "docker-entrypoint.s…"   43 seconds ago      Up 39 seconds       3306/tcp            mariadbdemo

To list all running and stopped containers, use docker ps -a command.

To get just the running container IDs;

docker ps -q

Checking MariaDB Container Logs

You can use docker logs <name-or-container-id> command;

docker logs mariadbdemo

Or

docker logs ce03099cfffa

Accessing MariaDB Docker Container

Your MariaDB docker container is now running in the background. You can access it by:

• Launching the interactive shell of the container
• Logging into MariaDB Docker container using mysql client from your host via the docker network.

To launch an interactive bash shell for the MariaDB docker container, use the docker exec -it <name-of the container|container-id> <shell>.

docker exec -it mariadbdemo bash

This takes you to container interactive bash shell;

root@9f26c99c35a5:/#

You can as well login to your MariaDB container using mysql client on your host.

For this, you need to install MySQL client. For example, on Ubuntu systems, you can install MySQL client by running the command

apt install mysql-client

Next, obtain the IP address assigned to your MariaDB container. To obtain an IP address of the container, use the docker inspect <name-of-the-container|container-id> command which provides a complete details about the container.

docker inspect mariadbdemo | grep IPAddress

            "SecondaryIPAddresses": null,
            "IPAddress": "172.17.0.2",
                    "IPAddress": "172.17.0.2",

In this case, our MariaDB container is assigned an IP address of 172.17.0.2.

To use the MySQL host client to connect to our container;

mysql -u root -p -h 172.17.0.2

The command assumes that the container is listening on a default port, 3306.

You will need to use the password that you specified with the MYSQL_ROOT_PASSWORD variable when running the container above.

Enter password: password
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.5.5-10.5.4-MariaDB-1:10.5.4+maria~focal mariadb.org binary distribution

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

Within the shell, you can now administer your MariaDB as you would when running on a host.

NOTE: The IP address assigned to your docker container is dynamic and if you happen to restart the container, it will be assigned a new/different IP address within the docker network.

Accessing MariaDB Docker Container Externally

If you have some external applications that needs to access your database running on MariaDB container, you need to expose the container port for external via the host system. By default, the container is only accessible within the host system

For example, our MariaDB container is listening on the default port 3306.

If you check your listening ports on your host for MariaDB port, you wont find any;

ss -altnp | grep 3306

To expose a container port, use the docker run options, -p <host-port>:<container-port>. See example command below to expose MariaDB container port 3306 via the host using the same port;

docker run --name mariadbdemoport -p 3306:3306 -e MYSQL_ROOT_PASSWORD=password -d mariadb

If you need to use the same names for the container, just stop the existing container and remove it and relaunch new container using the same name.

Let us verify the port exposure

docker ps

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
3489ce131cce        mariadb             "docker-entrypoint.s…"   4 minutes ago       Up 2 seconds        0.0.0.0:3306->3306/tcp   mariadbdemoport
ce03099cfffa        mariadb             "docker-entrypoint.s…"   About an hour ago   Up 40 seconds       3306/tcp                 mariadbdemo

If you check on the PORTS column, you realize for our new container, the container port is exposed on port 3306 on the host and is listening on all interfaces;

If you need to specify the IP address of the host, use -p host-IP-address:Port:<container-port>.

Checking the listening ports on the host again;

ss -altnp | grep 3306

LISTEN   0        4096                   *:3306                *:*

If you need to map the container port to a dynamic host port, use the option;

-p <container-port>

docker run --name mariadbdemo-dport -p 3306 -e MYSQL_ROOT_PASSWORD=password -d mariadb

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                     NAMES
bee9f036aedd        mariadb             "docker-entrypoint.s…"   8 seconds ago       Up 3 seconds        0.0.0.0:32768->3306/tcp   mariadbdemo-dport
3489ce131cce        mariadb             "docker-entrypoint.s…"   12 minutes ago      Up 7 minutes        0.0.0.0:3306->3306/tcp    mariadbdemoport
ce03099cfffa        mariadb             "docker-entrypoint.s…"   About an hour ago   Up 8 minutes        3306/tcp                  mariadbdemo

As you can see, the container port is exposed on dynamic port 32768.

You can always find what dynamic port the container port is mapped to using the docker port command;

docker port mariadbdemo-dport

3306/tcp -> 0.0.0.0:32768

Setting Persisting Data Volume for MariaDB Docker Container

When a container is removed, all if its data it had written to its internal volumes are removed as well. To ensure data is persistent across container deletes, you can map MariaDB Docker container internal volume to some host directory.

To bind an internal Docker volume to an external host volume, use the -v <host-directory>:<container-directory> option of docker run command.

The default data directory for MariaDB container is /var/lib/mysql.

For example, if I want the container data to be written to my host directory /opt/mariadb/data, the first create the directory and run a container mapping the data directories using the -v option.

mkdir -p /opt/mariadb/data

docker run --name mariadbdemo-volume -v /opt/mariadb/data:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=password -d mariadb

Therefore, any container data that is written to the container data directory, /var/lib/mysql, will be written to the data directory on host, /opt/mariadb/data at the same time.

Stop, Pause, Restart Remove Docker Container

To stop a running container, use the docker stop command;

docker stop [option] <name|id>

docker stop mariadbdemo

You can stop all containers using their ids;

docker stop $(docker ps -q)

Once you are done with a container, you can choose to remove it;

docker rm [option] <name|id>

docker rm mariadbdemo

To force removal;

docker rm --force mariadbdemo

To pause the container;

docker pause mariadbdemo

To restart;

docker restart mariadbdemo

To list docker volumes;

docker volume ls

Find specific docker container volume using docker inspect command.

Remove specific volume;

docker volume rm volume-name

Reference

Docker Documentation

MariaDB – Docker Hub

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