The only exception I make on the statement of not having persistent storage in a container is volatile testing environments. If you have a testing environment you intend to only use for a couple of hours, using a container to serve a database is not a bad thing at all. What you need to remember, if your container stops, all your data is gone.
Getting started with MySQL in Docker
To get started with MySQL in a Docker container you first have to pull it from the Docker registry. You can pull the official container image from Docker as shown in the example below which is done on Oracle Linux:
[root@docker ~]# docker pull mysql Using default tag: latest latest: Pulling from library/mysql 2a72cbf407d6: Pull complete 38680a9b47a8: Pull complete 4c732aa0eb1b: Pull complete c5317a34eddd: Pull complete f92be680366c: Pull complete e8ecd8bec5ab: Pull complete 2a650284a6a8: Pull complete 5b5108d08c6d: Pull complete beaff1261757: Pull complete c1a55c6375b5: Pull complete 8181cde51c65: Pull complete Digest: sha256:691c55aabb3c4e3b89b953dd2f022f7ea845e5443954767d321d5f5fa394e28c Status: Downloaded newer image for mysql:latest [root@docker ~]#
Now, this should give you the latest evrsion of the MySQL container image. You can check this witht the docker images command as shown below:
[root@docker ~]# docker images | grep mysql mysql latest 5195076672a7 4 days ago 371MB [root@docker ~]#
Start MySQL in Docker
To start MySQL you can use the below command as an example. As you can see this is a somewhat more extended command than you might see on the Docker page for MySQL.
docker run --name testmysql -e MYSQL_ROOT_PASSWORD=verysecret -p 3306:3306 --rm -d mysql
What I have added in the above example is that I map the internal port 3306 to an external port 3306. If you run multiple instances of MySQL you will need to change the external port numbers. I also added --rm to ensure the docker image is not persisted in any way or form as soon as you stop it.
After starting the container you should be able to find it with a docker ps command:
[root@docker ~]# docker ps |grep mysql 5d8f8bac45a1 mysql "docker-entrypoint..." 8 minutes ago Up 8 minutes 0.0.0.0:3306->3306/tcp testmysql [root@docker ~]#
Use databases in Docker?
As already stated, and actually the reason I wrote this post, you should not run anything in a container where you will need to have persistent storage available within the container itself. Databases are a good example of this. Based upon that statement you should not run a database in a container. Having stated that, if you can live with the fact you might lose all your data (for example in a quick test setup) there is nothing against running a database in a container.
Just make sure you don't do it with your production data (please....).