How to Persist Data in Docker Containers?

Hey there 👋,

By default, Docker containers are ephemeral, meaning that any data created inside the container is lost when the container is stopped or removed. But don’t worry, there’s a simple way to persist data in Docker by using volumes or bind mounts.

Here’s a quick breakdown of the two:

1. Docker Volumes Docker manages volumes and stores them outside the container’s file system. This is the recommended way to persist data in Docker because volumes are easier to manage and are independent of the container lifecycle. You can create a volume using this command:

   docker volume create my_data_volume
   

   Then, when you run your container, you can attach the volume like this:

   docker run -d -v my_data_volume:/path/inside/container my_container
   

   This way, any data in /path/inside/container will persist even if the container is stopped or removed!

2. Bind Mounts With bind mounts, you link a directory on your host system to a directory inside your container. This is useful if you want to access specific files on your host machine directly. Here’s how you can set it up:

   docker run -d -v /host/path:/container/path my_container
   

   In this case, the files in /host/path on your machine will be available inside the container at /container/path.

So, if you’re running something like a MySQL or a web application that needs persistent storage, volumes are the way to go!

If you want to dive deeper into Docker and learn all about managing containers and volumes, check out this free Docker ebook: Introduction to Docker.

Let me know if you need any more help!

\— Bobby