feat: publish p2 update site to GitHub Pages via gh-pages branch

.github/scripts/cleanup-p2-snapshots.sh

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+# Removes old p2 snapshots from gh-pages, keeping the last 20.
+# Ordering uses the .created timestamp written by publish-p2-ghpages.sh;
+# dirs without that file (pre-dating this change) are treated as oldest.
+# Required env vars: GITHUB_TOKEN
+
+set -euo pipefail
+
+KEEP=20
+
+cd gh-pages
+git config user.email "github-actions[bot]@users.noreply.github.com"
+git config user.name "github-actions[bot]"
+
+if [ -d p2/snapshots ]; then
+  to_delete=$(
+    for d in $(ls -1 p2/snapshots | grep -v latest); do
+      ts=0
+      [ -f "p2/snapshots/$d/.created" ] && ts=$(cat "p2/snapshots/$d/.created")
+      printf '%s %s\n' "$ts" "$d"
+    done | sort -n | head -n -"$KEEP" | awk '{print $2}'
+  )
+  if [ -n "$to_delete" ]; then
+    echo "$to_delete" | xargs -I{} rm -rf "p2/snapshots/{}"
+  fi
+fi
+
+git add -A
+if git diff --cached --quiet; then
+  echo "No snapshot cleanup needed"
+  exit 0
+fi
+git commit -m "Clean up old p2 snapshots"
+for attempt in 1 2 3; do
+  if git push origin HEAD:gh-pages; then
+    exit 0
+  fi
+  echo "Push attempt $attempt failed; fetching and rebasing"
+  git fetch origin gh-pages
+  git rebase origin/gh-pages
+done
+echo "Failed to push gh-pages after 3 attempts"
+exit 1

.github/scripts/publish-p2-ghpages.sh

@@ -0,0 +1,127 @@
+#!/usr/bin/env bash
+# Publishes the p2 update site to the gh-pages branch.
+#
+# Snapshot mode (RELEASE_VERSION unset):
+#   Copies ddk-repository/target/repository/ → p2/snapshots/<sha8>/
+#   Updates p2/snapshots/latest/ composite repository
+#
+# Release mode (RELEASE_VERSION set):
+#   Copies p2/snapshots/<SNAPSHOT_SHA>/ → p2/releases/<RELEASE_VERSION>/
+#   Updates p2/releases/latest/ composite repository
+#
+# Required env vars: GITHUB_TOKEN, GITHUB_SHA, GITHUB_REPOSITORY
+# Release-only vars: RELEASE_VERSION, SNAPSHOT_SHA
+
+set -euo pipefail
+
+write_composite() {
+  local dir="$1"
+  local name="$2"
+  local child="$3"
+  rm -rf "$dir"
+  mkdir -p "$dir"
+  cat > "$dir/p2.index" << 'EOF'
+version=1
+metadata.repository.factory.order=compositeContent.xml,\!
+artifact.repository.factory.order=compositeArtifacts.xml,\!
+EOF
+  cat > "$dir/compositeContent.xml" << EOF
+<?xml version='1.0' encoding='UTF-8'?>
+<?compositeMetadataRepository version='1.0.0'?>
+<repository name='$name' type='org.eclipse.equinox.internal.p2.metadata.repository.CompositeMetadataRepository' version='1.0.0'>
+  <properties size='1'><property name='p2.timestamp' value='$TIMESTAMP'/></properties>
+  <children size='1'><child location='$child'/></children>
+</repository>
+EOF
+  cat > "$dir/compositeArtifacts.xml" << EOF
+<?xml version='1.0' encoding='UTF-8'?>
+<?compositeArtifactRepository version='1.0.0'?>
+<repository name='$name' type='org.eclipse.equinox.internal.p2.artifact.repository.CompositeArtifactRepository' version='1.0.0'>
+  <properties size='1'><property name='p2.timestamp' value='$TIMESTAMP'/></properties>
+  <children size='1'><child location='$child'/></children>
+</repository>
+EOF
+}
+
+cd gh-pages
+git config user.email "github-actions[bot]@users.noreply.github.com"
+git config user.name "github-actions[bot]"
+
+touch .nojekyll
+
+if [ -n "${RELEASE_VERSION:-}" ]; then
+  TARGET="p2/releases/$RELEASE_VERSION"
+  REF_DESC="release $RELEASE_VERSION"
+  rm -rf "$TARGET"
+  mkdir -p "$TARGET"
+  cp -r "p2/snapshots/$SNAPSHOT_SHA/." "$TARGET/"
+else
+  TARGET="p2/snapshots/${GITHUB_SHA::8}"
+  REF_DESC="snapshot ${GITHUB_SHA::8}"
+  rm -rf "$TARGET"
+  mkdir -p "$TARGET"
+  cp -r ../ddk-repository/target/repository/. "$TARGET/"
+  date +%s > "$TARGET/.created"
+fi
+
+TIMESTAMP="$(date +%s)000"
+if [ -n "${RELEASE_VERSION:-}" ]; then
+  HIGHEST=$(ls -1 p2/releases | grep -v latest | sort -Vr | head -1)
+  write_composite p2/releases/latest "DDK p2 Latest Release" "../$HIGHEST/"
+else
+  SHORT_SHA="${GITHUB_SHA::8}"
+  write_composite p2/snapshots/latest "DDK p2 Latest Snapshot" "../$SHORT_SHA/"
+fi
+
+# Generate index.html
+{
+  echo '<!DOCTYPE html>'
+  echo '<html><body>'
+  echo '<h1>DSL DevKit p2 Repository</h1>'
+  echo '<h2>Snapshots</h2>'
+  echo '<ul>'
+  if [ -d p2/snapshots/latest ]; then
+    echo '  <li><a href="p2/snapshots/latest/">Latest Snapshot</a></li>'
+  fi
+  if [ -d p2/snapshots ]; then
+    while IFS= read -r s; do
+      echo "  <li><a href=\"p2/snapshots/$s/\">$s</a></li>"
+    done < <(
+      for d in $(ls -1 p2/snapshots | grep -v latest); do
+        ts=0
+        [ -f "p2/snapshots/$d/.created" ] && ts=$(cat "p2/snapshots/$d/.created")
+        printf '%s %s\n' "$ts" "$d"
+      done | sort -rn | head -20 | awk '{print $2}'
+    )
+  fi
+  echo '</ul>'
+  if [ -d p2/releases ] && [ -n "$(ls -A p2/releases 2>/dev/null)" ]; then
+    echo '<h2>Releases</h2>'
+    echo '<ul>'
+    if [ -d p2/releases/latest ]; then
+      echo '  <li><a href="p2/releases/latest/">Latest Release</a></li>'
+    fi
+    for v in $(ls -1 p2/releases | grep -v latest | sort -Vr); do
+      echo "  <li><a href=\"p2/releases/$v/\">$v</a></li>"
+    done
+    echo '</ul>'
+  fi
+  echo '</body></html>'
+} > index.html
+
+git add -A
+if git diff --cached --quiet; then
+  echo "No changes to publish"
+  exit 0
+fi
+git commit -m "Publish $REF_DESC"
+for attempt in 1 2 3; do
+  if git push origin HEAD:gh-pages; then
+    exit 0
+  fi
+  echo "Push attempt $attempt failed; fetching and rebasing"
+  git fetch origin gh-pages
+  git rebase origin/gh-pages
+done
+echo "Failed to push gh-pages after 3 attempts"
+exit 1

.github/workflows/release.yml

@@ -0,0 +1,156 @@
+name: release
+
+on:
+  workflow_dispatch:
+    inputs:
+      branch:
+        description: 'Branch to release from'
+        required: false
+        default: master
+        type: string
+      version_bump:
+        description: 'Version component to bump'
+        required: false
+        default: patch
+        type: choice
+        options:
+          - patch
+          - minor
+          - major
+
+concurrency:
+  group: publish-ghpages-${{ github.repository }}
+  cancel-in-progress: false
+
+permissions:
+  contents: write
+
+jobs:
+  create_tag:
+    runs-on: ubuntu-24.04
+    environment: release
+    outputs:
+      tag: ${{ steps.version.outputs.tag }}
+      snapshot_sha: ${{ steps.snapshot.outputs.sha }}
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6
+        with:
+          ref: ${{ inputs.branch }}
+          fetch-depth: 0
+
+      - name: Compute next version
+        id: version
+        run: |
+          LATEST=$(git tag --list 'v*' --sort=-version:refname | head -1)
+          if [ -z "$LATEST" ]; then
+            LATEST="v0.0.0"
+          fi
+          VERSION="${LATEST#v}"
+          MAJOR=$(echo "$VERSION" | cut -d. -f1)
+          MINOR=$(echo "$VERSION" | cut -d. -f2)
+          PATCH=$(echo "$VERSION" | cut -d. -f3)
+          case "${{ inputs.version_bump }}" in
+            major) MAJOR=$((MAJOR+1)); MINOR=0; PATCH=0 ;;
+            minor) MINOR=$((MINOR+1)); PATCH=0 ;;
+            patch) PATCH=$((PATCH+1)) ;;
+          esac
+          NEW_TAG="v${MAJOR}.${MINOR}.${PATCH}"
+          echo "tag=$NEW_TAG" >> "$GITHUB_OUTPUT"
+          echo "Previous version $LATEST → next version $NEW_TAG"
+
+      - name: Set snapshot SHA
+        id: snapshot
+        run: echo "sha=$(git rev-parse --short=8 HEAD)" >> "$GITHUB_OUTPUT"
+
+      - name: Check out gh-pages branch
+        id: checkout-gh-pages
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6
+        with:
+          ref: gh-pages
+          path: gh-pages
+          fetch-depth: 1
+        continue-on-error: true
+
+      - name: Verify snapshot exists for release
+        run: |
+          SHA="${{ steps.snapshot.outputs.sha }}"
+          if [ "${{ steps.checkout-gh-pages.outcome }}" != "success" ]; then
+            echo "::error::gh-pages branch does not exist; no snapshot available for commit $SHA"
+            exit 1
+          fi
+          if [ ! -d "gh-pages/p2/snapshots/$SHA" ]; then
+            echo "::error::No snapshot found for commit $SHA in p2/snapshots/; the commit must be built and deployed as a snapshot before releasing"
+            exit 1
+          fi
+          echo "Found snapshot for commit $SHA"
+
+      - name: Create and push tag
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          echo "Bumping to ${{ steps.version.outputs.tag }}"
+          git tag "${{ steps.version.outputs.tag }}"
+          git push origin "${{ steps.version.outputs.tag }}"
+
+  publish:
+    needs: create_tag
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6
+        with:
+          ref: ${{ needs.create_tag.outputs.tag }}
+          fetch-depth: 0
+
+      - name: Check out gh-pages branch
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6
+        with:
+          ref: gh-pages
+          path: gh-pages
+          fetch-depth: 1
+
+      - name: Publish p2 release to gh-pages
+        run: bash .github/scripts/publish-p2-ghpages.sh
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          RELEASE_VERSION: ${{ needs.create_tag.outputs.tag }}
+          SNAPSHOT_SHA: ${{ needs.create_tag.outputs.snapshot_sha }}
+
+      - name: Create release with p2 update site
+        run: |
+          RELEASE_VERSION="${{ needs.create_tag.outputs.tag }}"
+          SNAPSHOT_SHA="${{ needs.create_tag.outputs.snapshot_sha }}"
+          mkdir -p release-staging/repository
+          cp -r "gh-pages/p2/snapshots/$SNAPSHOT_SHA/." release-staging/repository/
+          cd release-staging
+          zip -r p2-update-site.zip repository/
+          gh release create "$RELEASE_VERSION" \
+            p2-update-site.zip \
+            --generate-notes \
+            --title "Release ${RELEASE_VERSION#v}"
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Summary
+        run: |
+          TAG="${{ needs.create_tag.outputs.tag }}"
+          REPO="${{ github.server_url }}/${{ github.repository }}"
+          echo "::notice::Created release $TAG from branch ${{ inputs.branch }}"
+          {
+            echo "## Release created"
+            echo ""
+            echo "| | |"
+            echo "|---|---|"
+            echo "| **Tag** | [$TAG]($REPO/releases/tag/$TAG) |"
+            echo "| **Branch** | \`${{ inputs.branch }}\` |"
+            echo "| **Bump** | \`${{ inputs.version_bump }}\` |"
+          } >> "$GITHUB_STEP_SUMMARY"
+
+# Release workflow:
+#   Snapshots:  every push to master or v[0-9]* branches → see snapshot.yml
+#   Release:    workflow_dispatch → create tag, promote snapshot to p2/releases/<version>/
+#
+# p2 repository URLs (GitHub Pages):
+#   Latest snapshot: https://dsldevkit.github.io/dsl-devkit/p2/snapshots/latest/
+#   Pinned snapshot: https://dsldevkit.github.io/dsl-devkit/p2/snapshots/<sha>/
+#   Latest release:  https://dsldevkit.github.io/dsl-devkit/p2/releases/latest/
+#   Pinned release:  https://dsldevkit.github.io/dsl-devkit/p2/releases/{version}/