Question
How do I transfer a Docker image from one machine to another one without using a repository, no matter private or public?
I create my own image in VirtualBox, and when it is finished I try to deploy to other machines to have real usage.
Since it is based on my own based image (like Red Hat Linux), it cannot be recreated from a Dockerfile. My dockerfile isn't easily portable.
Are there simple commands I can use? Or another solution?
Answer
You will need to save the Docker image as a tar file:
docker save -o <path for generated tar file> <image name>
Then copy your image to a new system with regular file transfer tools such as
cp, scp, or rsync (preferred for big files). After that you will have to
load the image into Docker:
docker load -i <path to image tar file>
You should add filename (not just directory) with -o, for example:
docker save -o c:/myfile.tar centos:16
PS: You may need to sudo all commands.
