Improve kubectl cp, so it doesn't require the tar binary in the container #58512
Description
Uncomment only one, leave it on its own line:
/kind feature
What happened:
Kubectl cp currently requires the container we're copying into to include the tar binary. This is problematic when the container image is minimal and only includes the main binary run in the container and nothing else.
What you expected to happen:
Docker now has docker cp, which can copy files into a running container without any prerequisites on the container itself. Kubectl cp could use that mechanism. Obviously, this will require introducing a new feature into CRI, so it's not a small task.
Why we need this:
This will enable users to debug an existing (running) container, which is based on the scratch image and contains nothing else but the main app binary. Users would be able to get any binary they need into the container. An alternative solution could be to mount an additional volume (possibly from another container image) into a running pod (if that feature is ever implemented).