barebones-docker-compose-mysql

A barebones implementation of MySQL running in a Docker container.

There are many like it, but this one is mine.

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Setup Steps

• Install Docker Desktop (https://docs.docker.com/engine/install/) or another containerization provider of your choice.
  • One good alternative is Rancher Desktop.
• WINDOWS USERS:
  • If you are using Docker Desktop and have a Nvidia graphics card, you may want to select the installation option that uses Hyper-V
    • If you get an error message about "Hardware assisted virtualization":
    • This Stack Overflow article proved useful.

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Running the Docker Container

• Ensure Docker Desktop is running.
• BEFORE you create the container, be sure to add any desired setup files to the setup_scripts directory.
• From the root of the project, run

docker compose up -d

• Breaking down the parts of the command...
  • The -d flag is optional, and is used to run in detached mode, (to not keep the command line tied up.)
  • The first time it runs, it will pull and download a docker image made for MySQL
    • You should see a message that looks something like this: /usr/sbin/mysqld: ready for connections. Version: '8.0.31' socket: '...' port: 3306
• In a new terminal, run the command

docker ps

• This shows a list of running docker containers. You should see our docker container listed there.

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Accessing MySQL inside the Docker Container

I followed Mahbub Zaman's tutorial for a good part of the docker compose portion.

• Once your Docker container is up and running, use the following command to enter it.

docker exec -it barebones-docker-compose-mysql-db-1 bash

• Breaking down the parts of the command...
  • docker exec allows us to interact with the running container.
  • -it makes the interaction continuous.
  • Substitute barebones-docker-compose-mysql-db-1 with whatever name Docker gave your container. (This can be found using docker ps).
  • bash gives us a bash shell once we are inside the container.
• Now that we are inside the container, we can connect to MySQL with the following command.

mysql -uroot -proot

• Explanation of this command...
  • -u and -p pass the username and password, respectively (and should not have a space before the argument). By default, in the docker-compose file, we have them set to be "root" and "root". This is a common pattern for databases that are only used locally.
  • If, somehow, you have come across this tutorial for more serious work, don't do this in prod.
  • If this username and password combination is successful, you should now see a command line prompt that leads with mysql>
  • Run the query SHOW DATABASES;
    • This will show all databases that have been created, and is a good way to check that your access is set up correctly.
    • Note: Be sure to include the semicolon, or the query will wait for you to enter the next line. If that happens, just enter a semicolon and then hit enter.

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Adding Test Data to the Database from a file

• If you are still in the mysql command line, use exit to get back to the bash shell.
• Files in the setup_scripts directory are accessible inside our container because we mounted them in the docker-compose.yml file.
• To load a file, use the following command, where the argument after the < symbol is the sql file you want to load.

mysql -uroot -p gvu_databases < school.sql/school.sql

Ensure the data loaded

• First, we need to tell MySQL which database we are using. The database name is defined around line 8 of docker-compose.yml

USE gvu_databases;

• Next, run the command to list all tables.

SHOW TABLES;