Motivation for this change

when trying to provision my k8s cluster from nix-channel unstable, I got the following error.

error: anonymous function at /home/xxx/github/nixos/nixpkgs/pkgs/build-support/docker/default.nix:38:5 called without required argument 'imageDigest', at /home/xxx/github/nixos/nixpkgs/nixos/modules/services/cluster/kubernetes/dns.nix:8:22

It seem the imageDigest is now required. I download all the docker images affected and tested their digest with skopeo

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.