sigs.k8s.io/kustomize/cmd/k8scopy (go): k8scopy is a code reuse mechanism for k8s.io code.  kustomize, kyaml, cmd/config are kustomize repo modules that want to reuse some small bits of k8s.io code. These modules cannot depend k8s.io via normal Go import or vendoring because kubectl will depend on these things eventually (see kubernetes-sigs/kustomize/issues/1500), and kubectl's code reuse is tricky. While kubectl remains in the k/k repo, it depends on local relative symlinked paths to a 'staging' version of k8s.io code.  No code imported by kubectl can refer to any other version of k8s.io code, not by Go importing, not by Go vendoring.  This main exists to allow "go generate" to copy select k8s.io packages into the kustomize repo at well defined tags in reproducible fashion.  It's a form of vendoring reuse that avoids the problems created by k8s staging. The copied code is labelled as generated and is not otherwise edited.  When/if kubectl is finally extracted from k/k to its own repo, it can depend on k8s.io code via normal imports, and then so can kustomize, so this technique can be dropped.  Until then, if a bug is found in a particular instance of copied k8s.io (highly unlikely, since only old stable versions are copied), just update the version being copied, re-generate, and if need be adjust call points.
Keywords: hacktoberfest|k8s-sig-cli