How to Create Databases Using Docker

Mon, 18 Sep 2023 19:47:33 -0600

The other day, I needed to set up a PostgreSQL database, and after considering various solutions, I decided to use Docker. In this tutorial, I’ll share the solution that worked for my problem.

Creating a PostgreSQL Database Using Docker Compose

Docker Compose is a powerful tool that allows us to manage multiple containers from a single central point. You might think it’s a bit much for setting up a database, but I found it surprisingly easy to set up and use.

Let’s start!

Creating the docker-compose.yml File

Docker Compose requires a configuration file named docker-compose.yml where we define and configure our containers. Writing this file is straightforward; here’s the one I used for my database:

version: '3'
services:
  postgres-db:
    image: postgres:latest
    container_name: postgres_container
    volumes:
      - "/path_to_local_storage:/var/lib/postgresql/data"
    environment:
      - POSTGRES_DB=my_db
      - POSTGRES_USER=user
      - POSTGRES_PASSWORD=password
    ports:
      - '5433:5432'

In the above file:

We define a service named postgres-db containing the PostgreSQL database image.
You can customize the container_name to your preference.
To ensure data persistence and choose a custom storage location, define your preferred local path in the ‘volumes’ section.
Set your database credentials (user, password) and the default database name in the environment section.
The port mapping is configured to use the default PostgreSQL ports. You can adjust this mapping if necessary; the format is local_machine_port:docker port.

Starting the database

To start your database, open a terminal in the directory where your docker-compose.yml is located (or specify a relative path to the file) and run this command (assuming you’re using Docker Compose 2):

docker compose -p example up -d

This command creates the containers defined in the compose file. You can customize the project name with the -p property.

Stopping the database

To stop your database, use this command:

docker compose down

Connecting locally to the database

Connecting to the database locally on your computer is simple. Access http://localhost:5433 using your chosen username and password. While I use DataGrip to connect, any database software can connect to it.

Troubleshooting

During the container creation process, I encountered some common issues, along with their solutions.

Issue: The image exited with code 1.

If your container exits immediately when launched, check the container logs by running:

docker logs my_container_name

I discovered that my data directory contained hidden files that caused this issue. Deleting these hidden files allowed the database to start and function as expected.

Issue: The mounting point is not valid.

If you encounter issues starting the image, it may be related to the local path name. If your path contains spaces, a simple workaround is to enclose the path in double quotes.

Conclusion

By utilizing docker-compose, we can easily start and manage data persistence for our databases. This method provides a straightforward and quick way to create databases with data persistence. I hope this tutorial proves as helpful to you as it was to me.

Happy coding!

Database on entangledDEV