Air-gap installations and nerdctl

k3s, k3OS, and k3d
1

I was successfully using the air-gap ‘https://rancher.com/docs/k3s/latest/en/installation/airgap/#prepare-the-images-directory-and-k3s-binaryManually deploy images method’ for my application images.

However, I moved from docker-desktop to rancher-desktop (uses nerdctl) but now the ‘nerdctl save’ command creates a tar file in a format that k3s cannot read (the tar has the ‘blobs’ folder). Previously, with docker, the tar was properly readable (the tar has the ‘repositories’ and ‘manifest.json’).

How can I instruct k3s to use the tar images in its ‘\var\lib\rancher\k3s\agent\images’ folder to read the ‘blobs’ format?
Or the other way around , to have ‘nerdctl save’ create a tar with the ‘repositories’ and ‘manifest.json’ format?

Thanks

2

You can use skopeo to do this:

skopeo copy docker://docker.io/library/registry:2 docker-archive:./registry.tar:library/registry:2

the registry.tar should be in the correct format for k3s.

ref:
https://itnext.io/running-k3s-workload-in-a-restricted-environment-c2f593d19005