A Docker volume is a handy way to deploy a container with persistent storage or to share data between two containers. With this handy trick, you could deploy multiple websites that use the same volume housing their data. It’s a great feature that helps to give Docker more flexibility. I want to show you how to create and use a Docker volume, so you can enjoy simplified data sharing and persistent data with your containers.
The first thing you must do is create a new volume. Let’s call it shared-data, and the command for this would be
docker volume create --name shared-data
The directory housing that volume on Linux is /var/lib/docker/volumes.
Let’s deploy a Ubuntu container that uses the new volume with the command
docker run -ti -v shared-data:/shared-data ubuntu
This will land us on the running container’s bash prompt where we can create a file in the shared directory with the command
echo "Hello, TechRepublic" >> /shared-data/test.txt
Exit from that container, and stop it with the
exit
command.
Let’s deploy a second container that uses the same volume with the command
docker run -ti -v shared-data:/shared-data ubuntu
You should see that the new container has the test.txt file that was saved within the volume. Test that with the command
cat /shared-data/test.txt
and you should see Hello, TechRepublic.
Congratulations! You have just created your first Docker volume that can be used for any number of containers.
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If you are interested in learning more about Docker, check out the following resources in TechRepublic Academy:
- The 2023FullStack Developer Bundle
- Hacking and Securing Docker Containers
- Linux and Docker Coding Bundle
- Docker and Kubernetes mini-bundle
