Merge pull request #122971 from pohly/apidiff

hack: add apidiff.sh

hack/apidiff.sh

@@ -0,0 +1,154 @@
+#!/usr/bin/env bash
+
+# Copyright 2024 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.
+
+# This script checks the coding style for the Go language files using
+# golangci-lint. Which checks are enabled depends on command line flags. The
+# default is a minimal set of checks that all existing code passes without
+# issues.
+
+usage () {
+  cat <<EOF >&2
+Usage: $0 [-r <revision>] [directory]"
+   -r <revision>: only report issues in code added since that revision. Default is
+      the common base of origin/master and HEAD.
+   [package]: check directory instead of everything
+EOF
+  exit 1
+}
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/..
+source "${KUBE_ROOT}/hack/lib/init.sh"
+
+base="$(git merge-base origin/master HEAD)"
+while getopts "r:" o; do
+    case "${o}" in
+        r)
+            base="${OPTARG}"
+            if [ ! "$base" ]; then
+                echo "ERROR: -${o} needs a non-empty parameter" >&2
+                echo >&2
+                usage
+            fi
+            ;;
+        *)
+            usage
+            ;;
+    esac
+done
+shift $((OPTIND - 1))
+
+# Check specific directory or everything.
+targets=("$@")
+if [ ${#targets[@]} -eq 0 ]; then
+    # This lists all entries in the go.work file as absolute directory paths.
+    kube::util::read-array targets < <(
+        go list -f '{{.Dir}}' -m | while read -r d; do
+            # We need relative paths because we will invoke apidiff in
+            # different work trees.
+            d="$(realpath -s --relative-to="$(pwd)" "${d}")"
+            if [ "${d}" != "." ]; then
+                # sub-directories have to have a leading dot.
+                d="./${d}"
+            fi
+            echo "${d}"
+        done
+    )
+fi
+
+# Must be a something that git can resolve to a commit.
+# "git rev-parse --verify" checks that and prints a detailed
+# error.
+base="$(git rev-parse --verify "$base")"
+
+kube::golang::setup_env
+kube::util::ensure-temp-dir
+
+# Install apidiff and make sure it's found.
+export GOBIN="${KUBE_TEMP}"
+PATH="${GOBIN}:${PATH}"
+echo "installing apidiff into ${GOBIN}"
+go install golang.org/x/exp/cmd/apidiff@latest
+
+cd "${KUBE_ROOT}"
+
+# output_name targets a target directory and prints the base name of
+# an output file for that target.
+output_name () {
+    what="$1"
+
+    echo "${what}" | sed -e 's/[^a-zA-Z0-9_-]/_/g' -e 's/$/.out/'
+}
+
+# run invokes apidiff once per target and stores the output
+# file(s) in the given directory.
+run () {
+    out="$1"
+    mkdir -p "$out"
+    for d in "${targets[@]}"; do
+        apidiff -m -w "${out}/$(output_name "${d}")" "${d}"
+    done
+}
+
+# First the current code.
+run "${KUBE_TEMP}/after"
+
+WORKTREE="${KUBE_TEMP}/worktree"
+
+# Create a copy of the repo with the base checked out.
+git worktree add -f -d "${WORKTREE}" "${base}"
+# Clean up the copy on exit.
+kube::util::trap_add "git worktree remove -f ${WORKTREE}" EXIT
+
+# Base ready for apidiff.
+(
+    cd "${WORKTREE}"
+    run "${KUBE_TEMP}/before"
+)
+
+# Now produce a report. All changes get reported because exporting some API
+# unnecessarily might also be good to know, but the final exit code will only
+# be non-zero if there are incompatible changes.
+#
+# The report is Markdown-formatted and can be copied into a PR comment verbatim.
+res=0
+echo
+compare () {
+    what="$1"
+    before="$2"
+    after="$3"
+    changes=$(apidiff -m "${before}" "${after}" 2>&1 | grep -v -e "^Ignoring internal package") || true
+    echo "## ${what}"
+    if [ -z "$changes" ]; then
+        echo "no changes"
+    else
+        echo "$changes"
+        echo
+    fi
+    incompatible=$(apidiff -incompatible -m "${before}" "${after}" 2>&1) || true
+    if [ -n "$incompatible" ]; then
+        res=1
+    fi
+}
+
+for d in "${targets[@]}"; do
+    compare "${d}" "${KUBE_TEMP}/before/$(output_name "${d}")" "${KUBE_TEMP}/after/$(output_name "${d}")"
+done
+
+exit "$res"