Working with Docker Volumes

This series previews the new self-paced Containers for Developers and Quality Assurance (LFS254) training course from The Linux Foundation. In earlier articles, we installed Docker, introduced Docker Machine, performed basic Docker container and image operations, and looked at Dockerfiles and Docker Hub.

In this article, we’ll talk a bit about Docker Volumes and networking. To create a volume, we use the docker volume create command. And, to list the volumes, we use the docker volume list command.

To mount the volume inside a container, we need to use the -v option with the docker container run command. For example, we can mount the myvol volume inside the container at the /data location. After moving into the /data folder, we create two files there.

Next, we come out of the container and create a new container from the busybox image, but mounting the same myvol volume. The files that we created in the earlier container are available under /data. This way, we can share the content between the containers using the volumes. You can watch both of the videos below for details.

To review Docker networking, we first create a container from the nginx image. With the docker container inspect command, we can get the container’s IP address, but that IP address would be given by the docker0 bridge, which would not be accessible from the external world.

To access the container from the external world, we need to do port mapping between the host port and the container port. So, with the -p option added to the docker container run command, we can map the host port with the container port. For example, we can map Port 8080 of the host system with Port 80 of the container.

Once the port is mapped, we can access the container from the dockerhost by accessing the dockerhost on Port 8080.

Want to learn more? Access all the free sample chapter videos now!

This online course is presented almost entirely on video, and the material is prepared and presented by Neependra Khare (@neependra), Founder and Principal Consultant at CloudYuga, Docker Captain, and author of the Docker Cookbook.

Leave a Reply

Your email address will not be published.