If you spin a MySQL Docker container, you’ll notice that once the container is stopped, all the information is lost! In order not to lose any information from your MySQL Docker database, a volume will need to be attached to the container. Let’s do that!

Let’s create a new volume – this will be used to store all your database informaton

docker volume create mysql

Once the volume is created, it can be attached to a newly spun MySQL container

docker run --name mysql -e MYSQL_ROOT_PASSWORD=albert --mount source=mysql,target=/var/lib/mysql -d mysql

Any datatabses created on this MySQL instance is now preserved! Let’s test it out. Let’s connect to the container and create a new database:

docker exec -it mysql mysql -uroot -p

Supply your password (in this example, the password would be the value that we’ve supplied for the MYSQL_ROOT_PASSWORD – albert

Once you’re connected, let’s see the current databases. The default installation will have 4 default databases

SHOW DATABASES;

+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+

Let’s go ahead and create a new database!

CREATE DATABASE test;

If you get all the databases now, you should get the following

SHOW DATABASES;

+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| test |
+--------------------+

De-attach from MySQL – type exit. Let’s now remove the current container and re-create a new container; re-attach the previously created volume.

docker container rm mysql -f
docker run --name mysql -e MYSQL_ROOT_PASSWORD=albert --mount source=mysql,target=/var/lib/mysql -d mysql

Let’s re-attach and get the list of databases (don’t forget to supply the password):

docker exec -it mysql mysql -uroot -p
SHOW DATABASES;

The output should now read as follows – the database test still exists, even after deleting and re-creating the container

+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| test |
+--------------------+