How do I download Docker images without using the pull command?

Just an alternative - This is what I did in my organization for couchbase image where I was blocked by a proxy.

On my personal laptop (OS X)

~$ $ docker save couchbase > couchbase.tar
~$ ls -lh couchbase.docker
-rw-------  1 vikas  devops   556M 12 Dec 21:15 couchbase.tar
~$ xz -9 couchbase.tar
~$ ls -lh couchbase.tar.xz
-rw-r--r--  1 vikas  staff   123M 12 Dec 22:17 couchbase.tar.xz

Then, I uploaded the compressed tar ball to Dropbox and downloaded on my work machine. For some reason Dropbox was open :)

On my work laptop (CentOS 7)

$ docker load < couchbase.tar.xz

References

  • https://docs.docker.com/engine/reference/commandline/save/
  • https://docs.docker.com/engine/reference/commandline/load/

I just had to deal with this issue myself - downloading an image from a restricted machine with Internet access, but no Docker client for use on a another restricted machine with the Docker client, but no Internet access. I posted my question to the DevOps Stack Exchange site:

  • Downloading Docker Images from Docker Hub without using Docker

With help from the Docker Community I was able to find a resolution to my problem. What follows is my solution.


So it turns out that the Moby Project has a shell script on the Moby GitHub account which can download images from Docker Hub in a format that can be imported into Docker:

  • download-frozen-image-v2.sh

The usage syntax for the script is given by the following:

download-frozen-image-v2.sh target_dir image[:tag][@digest] ...

The image can then be imported with tar and docker load:

tar -cC 'target_dir' . | docker load

To verify that the script works as expected, I downloaded an Ubuntu image from Docker Hub and loaded it into Docker:

user@host:~$ bash download-frozen-image-v2.sh ubuntu ubuntu:latest
user@host:~$ tar -cC 'ubuntu' . | docker load
user@host:~$ docker run --rm -ti ubuntu bash
root@1dd5e62113b9:/#

In practice I would have to first copy the data from the Internet client (which does not have Docker installed) to the target/destination machine (which does have Docker installed):

user@nodocker:~$ bash download-frozen-image-v2.sh ubuntu ubuntu:latest
user@nodocker:~$ tar -C 'ubuntu' -cf 'ubuntu.tar' .
user@nodocker:~$ scp ubuntu.tar user@hasdocker:~

and then load and use the image on the target host:

user@hasdocker:~ docker load -i ubuntu.tar
user@hasdocker:~ docker run --rm -ti ubuntu bash
root@1dd5e62113b9:/#

I adapted a python script for having an OS independant solution: docker-drag

Use it like that, and it will create a TAR archive that you will be able to import using docker load :

python docker_pull.py hello-world
python docker_pull.py alpine:3.9
python docker_pull.py kalilinux/kali-linux-docker