feat: Added a workflow for automating pre-release PR

.github/PULL_REQUEST_TEMPLATE.md

@@ -12,3 +12,10 @@
 
 **Which issue(s) this PR fixes:** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*
 Fixes #
+
+<!-- In case of the change being user-facing, an entry should be appended to the latest unreleased section in CHANGELOG.md.
+    The expected format is as follows:
+    - [ENHANCEMENT/CHANGE/BUGFIX/FEATURE]: <PR TITLE> by @PR_AUTHOR in https://github.com/kubernetes/kube-state-metrics/pull/<PR NUMBER> (avoid using #<PR NUMBER> for inter-VCS compatibility), for instance:
+    - [ENHANCEMENT]: Add support for Windows by @k8s-ci-robot in https://github.com/kubernetes/kube-state-metrics/pull/1234
+-->
+- [ ] I have added a CHANGELOG entry for this change.

.github/workflows/pre-release-pull-request.yml

@@ -0,0 +1,181 @@
+name: Pre-Release PR
+
+on:
+  workflow_dispatch:
+    inputs:
+      new_version:
+        description: 'The new release version (e.g., v2.10.0)'
+        required: true
+        type: string
+
+permissions:
+  contents: write
+  pull-requests: write
+
+env:
+  GO_VERSION: "^1.24"
+  GOLANGCI_LINT_VERSION: "v2.4.0"
+  E2E_SETUP_KIND: yes
+  E2E_SETUP_KUBECTL: yes
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Validate version format
+        run: |
+          if [[ ! "${{ inputs.new_version }}" =~ ^v[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
+            echo "Error: Version format is incorrect. It must be in the format 'vX.Y.Z'."
+            exit 1
+          fi
+          echo "Version format is valid."
+      - name: Checkout into the corresponding release branch
+        uses: actions/checkout@v4
+      - name: Checkout to release branch
+        run: |
+          git checkout -b prep-${{ inputs.new_version }}
+          MAJOR_MINOR_VERSION=$(echo "${{ inputs.new_version }}" | sed 's/^v//' | cut -d. -f1,2)
+          if git show-ref --verify --quiet refs/remotes/origin/release-$MAJOR_MINOR_VERSION; then
+            echo "Release branch release-$MAJOR_MINOR_VERSION already exists, switching to it"
+            git checkout -b release-$MAJOR_MINOR_VERSION origin/release-$MAJOR_MINOR_VERSION
+          else
+            echo "Creating new release branch release-$MAJOR_MINOR_VERSION"
+            git checkout -b release-$MAJOR_MINOR_VERSION
+            git push origin release-$MAJOR_MINOR_VERSION
+          fi          
+          git checkout prep-${{ inputs.new_version }}
+      - name: Set up the go@${{ env.GO_VERSION }} environment
+        uses: actions/setup-go@v5
+        with:
+          go-version: ${{ env.GO_VERSION }}
+      - name: Update the VERSION manifest
+        run: echo "${{ inputs.new_version }}" | sed 's/^v//' > VERSION
+      - name: Update data.yaml
+        run: ./scripts/update-data-yaml.sh "${{ inputs.new_version }}"
+      - name: Update the compatibility matrix (README.md)
+        run: make generate
+      - name: Move unreleased to released in CHANGELOG.md
+        run: ./scripts/generate-release-date.sh "${{ inputs.new_version }}"
+      - name: make lint-fix
+        run: |
+          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | \
+          sh -s -- -b $(go env GOPATH)/bin ${{ env.GOLANGCI_LINT_VERSION }}
+          make lint-fix
+      - name: Generate manifests
+        run: |
+            make clean || true
+            VERSION="${{ inputs.new_version }}" make examples
+      - name: Update the remote and commit the changes
+        run: |
+          git config --local user.email "${{ github.actor }}@users.noreply.github.com"
+          git config --local user.name "${{ github.actor }}"
+          git add .
+          git commit -m "chore: Cut ${{ inputs.new_version }}"
+          git push origin prep-${{ inputs.new_version }}
+      - name: Validate docs
+        run: make doccheck
+      - name: Validate manifests
+        run: make validate-manifests
+      - name: Validate go modules
+        run: make validate-modules
+      - name: Run rule tests
+        run: PROMTOOL_CLI=./promtool make install-promtool test-rules
+      - name: Run unit tests
+        run: make test-unit
+      - name: Run end-to-end tests
+        run: |
+          make e2e
+          find examples -name "*.yaml" -type f -exec sed -i 's|kube-state-metrics-amd64|kube-state-metrics|g; s|kube-state-metrics-arm64|kube-state-metrics|g' {} \;
+      - name: Run benchmark tests
+        run: |
+          BENCHSTAT_OUTPUT_FILE=result.txt ./tests/compare_benchmarks.sh main 2
+      - name: Post results to job summary
+        run: |
+          echo "### Benchmark Comparison Results" >> "$GITHUB_STEP_SUMMARY"
+          echo "\`\`\`" >> "$GITHUB_STEP_SUMMARY"
+          cat result.txt >> "$GITHUB_STEP_SUMMARY"
+          echo "\`\`\`" >> "$GITHUB_STEP_SUMMARY"
+      - name: Create a pull request
+        run: |
+          # Extract major.minor version for branch naming
+          MAJOR_MINOR_VERSION=$(echo "${{ inputs.new_version }}" | sed 's/^v//' | cut -d. -f1,2)
+
+          # Get the most recent tag for changelog generation
+          PREV_TAG=$(git tag --sort=-version:refname | head -n1 || echo "")
+
+          # Determine date range for PR search
+          if [[ -n "$PREV_TAG" ]]; then
+            PREV_TAG_DATE="$(git show -s --format=%cI "$PREV_TAG" 2>/dev/null || true)"
+            RANGE="${PREV_TAG}..HEAD"
+          else
+            PREV_TAG_DATE="1970-01-01T00:00:00Z"
+            PREV_REF="$(git rev-list --max-parents=0 HEAD)"
+            RANGE="${PREV_REF}..HEAD"
+          fi
+
+          # Format dates for PR search
+          PREV_DATE_SHORT="$(date -d "$PREV_TAG_DATE" +%Y-%m-%d 2>/dev/null || echo "1970-01-01")"
+          TAG_DATE_SHORT="$(date -u +%Y-%m-%d)"
+
+          # Extract changelog section for this version
+          CHANGELOG_SECTION=$(awk '/^## '"${{ inputs.new_version }}"'/{flag=1; next} /^## /{if(flag) exit} flag' CHANGELOG.md | \
+                              grep -E '^\s*\*\s*\[' | \
+                              sed 's/^/    /' || \
+                              echo "    No user-facing changes found for this version.")
+
+          # Get merged PRs in the date range
+          PR_LINES="$(gh pr list \
+                        --state merged \
+                        --search "merged:${PREV_DATE_SHORT}..${TAG_DATE_SHORT}" \
+                        --json number,title,author \
+                        --limit 1000 \
+                        --template '{{range .}}{{.number}}|{{.title}}|{{.author.login}}{{"\n"}}{{end}}')" || true
+
+          # Build full changelog from merged PRs
+          FULL_CHANGELOG_LINES=()
+          if [[ -n "$PR_LINES" ]]; then
+            while IFS= read -r line; do
+              if [[ -n "$line" ]]; then
+                prnum="${line%%|*}"
+                rest="${line#*|}"
+                title="${rest%%|*}"
+                login="${rest##*|}"
+                FULL_CHANGELOG_LINES+=("    - ${title} by @${login} in #${prnum}")
+              fi
+            done <<< "$PR_LINES"
+          fi
+
+          # Format full changelog text
+          FULL_CHANGELOG_TEXT=""
+          if [[ ${#FULL_CHANGELOG_LINES[@]} -gt 0 ]]; then
+            printf -v FULL_CHANGELOG_TEXT "%s\n" "${FULL_CHANGELOG_LINES[@]}"
+          else
+            FULL_CHANGELOG_TEXT="    (no merged PRs found in this release)"
+          fi
+
+          # Create PR body file to avoid quote issues
+          cat > pr_body.txt << EOF
+          This PR was automatically created by the release workflow.
+
+          ## Changelog
+
+          $CHANGELOG_SECTION
+
+          ## Full Changelog
+
+          $FULL_CHANGELOG_TEXT
+          EOF
+
+          # Create the pull request
+          gh pr create \
+            --title "chore: Cut ${{ inputs.new_version }}" \
+            --body-file pr_body.txt \
+            --base release-$MAJOR_MINOR_VERSION \
+            --head prep-${{ inputs.new_version }} \
+            --reviewer @sig-instrumentation-approvers \
+            --assignee @sig-instrumentation-leads
+
+          # Clean up temporary file
+          rm pr_body.txt
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.gitignore

@@ -43,3 +43,5 @@ help.txt
 
 # jsonnet dependency management
 /scripts/vendor
+
+promtool

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## Unreleased
+
+## Released
+
 ## v2.17.0 / 2025-09-01
 
 * This release builds with Go `v1.24.6`

scripts/generate-release-date.sh

@@ -0,0 +1,54 @@
+#!/bin/bash
+set -exuo pipefail
+
+SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+REPO_ROOT=$( cd -- "${SCRIPT_DIR}/.." &> /dev/null && pwd )
+CHANGELOG_FILE="${REPO_ROOT}/CHANGELOG.md"
+
+if [ -z "$1" ]; then
+    echo "Error: A version argument is required (e.g., v2.10.0)." >&2
+    exit 1
+fi
+new_version=$1
+
+# Determine the OS to use the correct version of sed.
+# shellcheck disable=SC2209
+SED=sed
+if [[ $(uname) == "Darwin" ]]; then
+  # Check if gnu-sed is installed.
+  if ! command -v gsed &> /dev/null; then
+      echo "gnu-sed is not installed. Please install it using 'brew install gnu-sed'." >&2
+      exit 1
+  fi
+  SED=gsed
+fi
+
+# Extract content between "## Unreleased" and "## Released"
+UNRELEASED_CONTENT=$($SED -n '/^## Unreleased/,/^## Released/{/^## Unreleased/d; /^## Released/d; p;}' "${CHANGELOG_FILE}")
+
+# Clear the Unreleased section (remove everything between "## Unreleased" and "## Released")
+$SED -i '/^## Unreleased/,/^## Released/{/^## Unreleased/!{/^## Released/!d;}}' "${CHANGELOG_FILE}"
+
+# Add an empty line after the Unreleased section
+$SED -i '/^## Unreleased/a\\' "${CHANGELOG_FILE}"
+
+# Add the new version section with date after "## Released"
+if [[ -n "$UNRELEASED_CONTENT" ]]; then
+    # Create a temporary file to avoid issues with quotes and special characters
+    TEMP_FILE=$(mktemp)
+    echo "" > "$TEMP_FILE"
+    echo "## $new_version / $(date +'%Y-%m-%d')" >> "$TEMP_FILE"
+    echo "" >> "$TEMP_FILE"
+    echo "$UNRELEASED_CONTENT" >> "$TEMP_FILE"
+
+    $SED -i "/^## Released/r $TEMP_FILE" "${CHANGELOG_FILE}"
+
+    rm "$TEMP_FILE"
+else
+    # If no content in Unreleased, just add the version header
+    $SED -i "/^## Released/a\\
+\\
+## $new_version / $(date +'%Y-%m-%d')" "${CHANGELOG_FILE}"
+fi
+
+echo "CHANGELOG.md updated successfully. Moved unreleased content to $new_version section."