Don't use docker daemon to download images (nodeadm download)

[asafo]

Trying to automate klusterkit packaging into a Dockerfile, but:

RUN nodeadm download

will fail: Failed to list images with error Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

I found no way to let the docker build command (re-)use the docker daemon.

There must be a way to implement this, i.e: download images and save to files, without running the docker cli and requiring a docker daemon (e.g: skopeo)

Thanks

[dlipovetsky]

Removing the dependency on docker is a worthwhile idea.

Not sure if there's a workaround for build, but there is for run. We run nodeadm in a container in our internal CI. Here's a slightly edited version of what we do:

	docker run \
		--user $(shell id --user):$(shell id --group) \
		--group-add $(shell getent group docker | cut -d: -f3) \
		--privileged \
		--volume /var/run/docker.sock:/var/run/docker.sock \
		--rm \
		${IMAGE} \
		/nodeadm download

[asafo]

Thanks,
I'm aware of this technique, just don't know how to do this in docker build,
Anyway, I have created a pull request
Which implements this, based on code from skopeo