Saving Images and Containers as Tar Files for Sharing

Docker - Beginners | Intermediate | Advanced

Imagine a scenario where you have built Docker images and containers that you would be interested to keep and share it with your other collaborators or colleagues. The below methods shall help you achieve it.

Four basic Docker CLI comes into action:

• The docker export - Export a container’s filesystem as a tar archive
• The docker import - Import the contents from a tarball to create a filesystem image
• The docker save - Save one or more images to a tar archive (streamed to STDOUT by default)
• The docker load - Load an image from a tar archive or STDIN

Tested Infrastructure

Platform	Number of Instance	Reading Time
Play with Docker	1	5 min

Pre-requisite

• Create an account with DockerHub

Create Nginx Container

docker run -d -p 80:80 nginx

Displaying Running Container

docker ps -a

docker export df2 > nginx.tar

You could commit this container as a new image locally, but you could also use the Docker import command:

docker import - mynginx < nginx.tar

If you wanted to share this image with one of your collaborators, you could upload the tar file on a web server and let your collaborator download it and use the import command on his Docker host.

If you would rather deal with images that you have already committed, you can use the load and save commands:

docker save -o mynginx1.tar nginx

$ ls -l
total 218756
-rw-------    1 root     root     112844800 Dec 18 02:53 mynginx1.tar
-rw-r--r--    1 root     root     111158784 Dec 18 02:50 nginx.tar

$ docker rmi mynginx
Untagged: mynginx:latest
Deleted: sha256:aaaed50d250a671042e8dc383c6e05012e245f5eaf555d10c40be63f6028ee7b
Deleted: sha256:41135ad184eaac0f5c4f46e4768555738303d30ab161a7431d28a5ccf1778a0f

Now delete all images and containers running and try to run the below command to load Docker image into your system:

$ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

docker load < mynginx1.tar