I recently had the need to copy a docker image I had created locally to another docker host.
If you need to move a Docker image to another system, or if you’d like to back up an image then you can do so by using the docker save and docker load commands.
First of all, check your image name by running docker image list:
$ docker image list REPOSITORY TAG IMAGE ID CREATED SIZE nimmis/vcsim latest a99cc435e5a0 7 days ago 922MB mcr.microsoft.com/powershell latest c60d38f77378 13 days ago 290MB bs4 latest 0143b79ec7b3 2 months ago 943MB centos centos7 5e35e350aded 2 months ago 203MB
Copy a Docker Image
To export your image to a tar file, run the docker save command, specifying a name for the .tar file, and the docker image name. This will save the docker image locally.
docker save -o image.tar centos
Also, note that you could add an image name during the export, for example:
docker save -o image.tar centos:v1
Next, copy your image to your target system. You could use SCP or another file transfer tool such as rsync. Once you have the image on the target system you can import the docker image by running the docker load command. This will load the docker image from the tar
docker load -i image.tar
You should get confirmation that your image has been loaded:
$ docker load -i image.tar Loaded image: centos:centos7 Loaded image: centos:latest
Now you can confirm that the image is available by running docker image list on the target system.
Final Thoughts
In this short article you have learnt how to copy a docker image using the docker save and docker load commands.