Generate a repos_generated.bzl file with all staging repos

Additionally, ensure that every staging repo has a BUILD file at its
root.

Also, remove a gazelle directive we no longer need.

hack/update-bazel.sh

@@ -18,7 +18,6 @@ set -o nounset
 set -o pipefail
 
 KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/..
-export KUBE_ROOT
 source "${KUBE_ROOT}/hack/lib/init.sh"
 
 # Ensure that we find the binaries we build before anything else.
@@ -30,14 +29,26 @@ go install k8s.io/kubernetes/vendor/github.com/bazelbuild/bazel-gazelle/cmd/gaze
 go install k8s.io/kubernetes/vendor/github.com/bazelbuild/buildtools/buildozer
 go install k8s.io/kubernetes/vendor/k8s.io/repo-infra/kazel
 
-touch "${KUBE_ROOT}/vendor/BUILD"
-# Ensure that we use the correct importmap for all vendored dependencies.
-# Probably not necessary in gazelle 0.13+
-# (https://github.com/bazelbuild/bazel-gazelle/pull/207).
-if ! grep -q "# gazelle:importmap_prefix" "${KUBE_ROOT}/vendor/BUILD"; then
-  echo "# gazelle:importmap_prefix k8s.io/kubernetes/vendor" >> "${KUBE_ROOT}/vendor/BUILD"
-fi
+while IFS='' read -r repo; do staging_repos+=("${repo}"); done <\
+  <(cd "${KUBE_ROOT}/staging/src" && find k8s.io/ -mindepth 1 -maxdepth 1 -type d | LANG=C sort)
 
+(
+  cat "${KUBE_ROOT}/hack/boilerplate/boilerplate.generatebzl.txt"
+  echo "# This file is autogenerated by hack/update-bazel.sh."
+  # avoid getting caught by the boilerplate checker
+  rev <<<".TIDE TON OD #"
+  echo
+  echo "staging_repos = ["
+  for repo in "${staging_repos[@]}"; do
+    echo "    \"${repo}\","
+  done
+  echo "]"
+) >"${KUBE_ROOT}/staging/repos_generated.bzl"
+
+touch "${KUBE_ROOT}/vendor/BUILD"
+for repo in "${staging_repos[@]}"; do
+  touch "${KUBE_ROOT}/staging/src/${repo}/BUILD"
+done
 gazelle fix \
     -external=vendored \
     -mode=fix \

vendor/BUILD

@@ -1,5 +1,3 @@
-# gazelle:importmap_prefix k8s.io/kubernetes/vendor
-
 filegroup(
     name = "package-srcs",
     srcs = glob(["**"]),