Mark staging go module files as generated, add script to lint dependencies

hack/lint-dependencies.sh

@@ -0,0 +1,69 @@
+#!/usr/bin/env bash
+
+# Copyright 2019 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/..
+source "${KUBE_ROOT}/hack/lib/init.sh"
+
+# Explicitly opt into go modules, even though we're inside a GOPATH directory
+export GO111MODULE=on
+# Explicitly clear GOPATH, to ensure nothing this script calls makes use of that path info
+export GOPATH=
+# Explicitly clear GOFLAGS, since GOFLAGS=-mod=vendor breaks dependency resolution while rebuilding vendor
+export GOFLAGS=
+# Detect problematic GOPROXY settings that prevent lookup of dependencies
+if [[ "${GOPROXY:-}" == "off" ]]; then
+  kube::log::error "Cannot run with \$GOPROXY=off"
+  exit 1
+fi
+
+kube::golang::verify_go_version
+kube::util::require-jq
+
+outdated=$(go list -m -json all | jq -r '
+  select(.Replace.Version != null) | 
+  select(.Version != .Replace.Version) | 
+  "\(.Path)
+    pinned:    \(.Replace.Version)
+    preferred: \(.Version)
+    hack/pin-dependency.sh \(.Path) \(.Version)"
+')
+if [[ -n "${outdated}" ]]; then
+  echo "These modules are pinned to versions different than the minimal preferred version."
+  echo "That means that without require directives, a different version would be selected."
+  echo "The command to switch to the minimal preferred version is listed for each module."
+  echo ""
+  echo "${outdated}"
+fi
+
+unused=$(comm -23 \
+  <(go mod edit -json | jq -r '.Replace[] | select(.New.Version != null) | .Old.Path' | sort) \
+  <(go list -m -json all | jq -r .Path | sort))
+if [[ -n "${unused}" ]]; then
+  echo ""
+  echo "Pinned module versions that aren't actually used:"
+  echo "${unused}"
+fi
+
+if [[ -n "${unused}${outdated}" ]]; then
+  exit 1
+fi
+
+echo "All pinned dependencies match their preferred version."
+exit 0