ci: promote immutable Maven release candidates

.github/scripts/create-central-bundle.sh

@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+if [[ $# -ne 2 ]]; then
+  echo "usage: $0 <version> <central-bundle.zip>" >&2
+  exit 1
+fi
+
+version=$1
+bundle=$2
+staging_root="target/central-bundle-staging"
+destination="${staging_root}/io/rstream/rstream/${version}"
+
+if [[ ! "$version" =~ ^[0-9]+(\.[0-9]+){2}$ ]]; then
+  echo "invalid release version: ${version}" >&2
+  exit 1
+fi
+if [[ -e "$staging_root" || -e "$bundle" ]]; then
+  echo "Maven Central bundle output already exists" >&2
+  exit 1
+fi
+
+mkdir -p "$destination" "$(dirname "$bundle")"
+artifacts=(
+  "target/rstream-${version}.pom"
+  "target/rstream-${version}.jar"
+  "target/rstream-${version}-sources.jar"
+  "target/rstream-${version}-javadoc.jar"
+)
+for artifact in "${artifacts[@]}"; do
+  for source in "$artifact" "${artifact}.asc"; do
+    if [[ ! -f "$source" ]]; then
+      echo "signed Maven artifact is missing: ${source}" >&2
+      exit 1
+    fi
+    cp "$source" "$destination/"
+  done
+done
+
+for artifact in "$destination"/*; do
+  md5sum "$artifact" | awk '{print $1}' > "${artifact}.md5"
+  sha1sum "$artifact" | awk '{print $1}' > "${artifact}.sha1"
+  sha256sum "$artifact" | awk '{print $1}' > "${artifact}.sha256"
+  sha512sum "$artifact" | awk '{print $1}' > "${artifact}.sha512"
+done
+
+bundle=$(cd "$(dirname "$bundle")" && pwd)/$(basename "$bundle")
+(
+  cd "$staging_root"
+  find io -type f -print | LC_ALL=C sort | zip -q "$bundle" -@
+)

.github/scripts/publish-maven-central.sh

@@ -0,0 +1,112 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+if [[ $# -ne 2 ]]; then
+  echo "usage: $0 <version> <central-bundle.zip>" >&2
+  exit 1
+fi
+
+version=$1
+bundle=$2
+repository_url="https://repo1.maven.org/maven2/io/rstream/rstream/${version}"
+work_directory=$(mktemp -d)
+trap 'rm -rf "$work_directory"' EXIT
+
+"$(dirname "$0")/verify-central-bundle.sh" "$version" "$bundle"
+unzip -q "$bundle" -d "$work_directory/bundle"
+candidate_directory="${work_directory}/bundle/io/rstream/rstream/${version}"
+
+verify_publication() {
+  local attempts=$1
+  local files=(
+    "rstream-${version}.pom"
+    "rstream-${version}.pom.asc"
+    "rstream-${version}.jar"
+    "rstream-${version}.jar.asc"
+    "rstream-${version}-sources.jar"
+    "rstream-${version}-sources.jar.asc"
+    "rstream-${version}-javadoc.jar"
+    "rstream-${version}-javadoc.jar.asc"
+  )
+  local attempt filename
+  for ((attempt = 1; attempt <= attempts; attempt++)); do
+    local complete=true
+    for filename in "${files[@]}"; do
+      if ! curl --fail --silent --show-error --location \
+        --output "${work_directory}/${filename}" "${repository_url}/${filename}"; then
+        complete=false
+        break
+      fi
+      if ! cmp --silent "${candidate_directory}/${filename}" "${work_directory}/${filename}"; then
+        echo "published Maven artifact differs from candidate: ${filename}" >&2
+        exit 1
+      fi
+    done
+    if [[ "$complete" == true ]]; then
+      return 0
+    fi
+    if ((attempt < attempts)); then
+      sleep 10
+    fi
+  done
+  return 1
+}
+
+publication_status=$(curl --silent --location --output /dev/null --write-out '%{http_code}' \
+  "${repository_url}/rstream-${version}.pom")
+if [[ "$publication_status" == 200 ]]; then
+  if ! verify_publication 12; then
+    echo "existing Maven Central release is incomplete" >&2
+    exit 1
+  fi
+  exit 0
+fi
+if [[ "$publication_status" != 404 ]]; then
+  echo "Maven Central availability check returned HTTP ${publication_status}" >&2
+  exit 1
+fi
+
+: "${MAVEN_CENTRAL_USERNAME:?MAVEN_CENTRAL_USERNAME is required}"
+: "${MAVEN_CENTRAL_PASSWORD:?MAVEN_CENTRAL_PASSWORD is required}"
+authorization=$(printf '%s:%s' "$MAVEN_CENTRAL_USERNAME" "$MAVEN_CENTRAL_PASSWORD" | base64 | tr -d '\n')
+printf '::add-mask::%s\n' "$authorization"
+deployment_id=$(curl --fail --silent --show-error \
+  --header "Authorization: Bearer ${authorization}" \
+  --form "bundle=@${bundle};type=application/octet-stream" \
+  "https://central.sonatype.com/api/v1/publisher/upload?publishingType=AUTOMATIC&name=rstream-${version}")
+if [[ ! "$deployment_id" =~ ^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$ ]]; then
+  echo "Maven Central returned an invalid deployment ID" >&2
+  exit 1
+fi
+
+for _ in {1..90}; do
+  status=$(curl --fail --silent --show-error --request POST \
+    --header "Authorization: Bearer ${authorization}" \
+    "https://central.sonatype.com/api/v1/publisher/status?id=${deployment_id}")
+  state=$(jq -r '.deploymentState' <<<"$status")
+  case "$state" in
+    PUBLISHED)
+      break
+      ;;
+    FAILED)
+      jq '.errors' <<<"$status" >&2
+      exit 1
+      ;;
+    PENDING | VALIDATING | VALIDATED | PUBLISHING)
+      sleep 10
+      ;;
+    *)
+      echo "unexpected Maven Central deployment state: ${state}" >&2
+      exit 1
+      ;;
+  esac
+done
+if [[ "$state" != PUBLISHED ]]; then
+  echo "Maven Central deployment did not reach PUBLISHED" >&2
+  exit 1
+fi
+if ! verify_publication 60; then
+  echo "Maven Central release did not become publicly verifiable" >&2
+  exit 1
+fi

.github/scripts/verify-central-bundle.sh

@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+if [[ $# -ne 2 ]]; then
+  echo "usage: $0 <version> <central-bundle.zip>" >&2
+  exit 1
+fi
+
+version=$1
+bundle=$2
+prefix="io/rstream/rstream/${version}"
+
+if [[ ! "$version" =~ ^[0-9]+(\.[0-9]+){2}$ ]]; then
+  echo "invalid release version: ${version}" >&2
+  exit 1
+fi
+if [[ ! -f "$bundle" ]]; then
+  echo "Maven Central bundle is missing: ${bundle}" >&2
+  exit 1
+fi
+
+unzip -tq "$bundle" >/dev/null
+if unzip -Z1 "$bundle" | awk -v prefix="${prefix}/" '
+  /^\// || /(^|\/)\.\.($|\/)/ || index($0, prefix) != 1 { invalid = 1 }
+  END { exit invalid }
+'; then
+  :
+else
+  echo "Maven Central bundle contains an unsafe path" >&2
+  exit 1
+fi
+
+required=(
+  "rstream-${version}.pom"
+  "rstream-${version}.jar"
+  "rstream-${version}-sources.jar"
+  "rstream-${version}-javadoc.jar"
+)
+entries=$(unzip -Z1 "$bundle")
+for filename in "${required[@]}"; do
+  for suffix in "" .asc; do
+    expected="${prefix}/${filename}${suffix}"
+    if ! grep -Fxq "$expected" <<<"$entries"; then
+      echo "Maven Central bundle is missing ${expected}" >&2
+      exit 1
+    fi
+  done
+done

.github/workflows/publish.yml

@@ -1,33 +1,102 @@
-name: Publish
+name: Promote stable release
+
 on:
-  release:
-    types:
-      - published
   workflow_dispatch:
+    inputs:
+      release_tag:
+        description: Reviewed candidate tag to publish
+        required: true
+        type: string
+
 permissions:
-  contents: read
+  actions: read
+  contents: write
+
+concurrency:
+  group: stable-release
+  cancel-in-progress: false
+
 jobs:
   publish:
+    name: Publish approved Maven Central bundle
+    if: ${{ github.actor == vars.CI_ALLOWED_ACTOR }}
+    environment: stable-release
     runs-on: ubuntu-latest
-    environment: maven-central
     steps:
+      - name: Find matching release candidate
+        id: release
+        shell: bash
+        env:
+          GH_TOKEN: ${{ github.token }}
+          RELEASE_TAG: ${{ inputs.release_tag }}
+        run: |
+          set -euo pipefail
+          if [[ ! "$RELEASE_TAG" =~ ^v[0-9]+(\.[0-9]+){2}$ ]]; then
+            echo "invalid release tag: ${RELEASE_TAG}" >&2
+            exit 1
+          fi
+          if [[ "$(gh api "repos/${GITHUB_REPOSITORY}/releases/tags/${RELEASE_TAG}" --jq '.draft')" != true ]]; then
+            echo "GitHub release ${RELEASE_TAG} must still be a draft" >&2
+            exit 1
+          fi
+          version=${RELEASE_TAG#v}
+          latest_tag=$(gh api "repos/${GITHUB_REPOSITORY}/releases/latest" --jq '.tag_name' 2>/dev/null || true)
+          if [[ -n "$latest_tag" && "$(printf '%s\n' "${latest_tag#v}" "$version" | sort -V | tail -n 1)" != "$version" ]]; then
+            echo "refusing to promote ${RELEASE_TAG} after newer release ${latest_tag}" >&2
+            exit 1
+          fi
+          tag_ref=$(gh api "repos/${GITHUB_REPOSITORY}/git/ref/tags/${RELEASE_TAG}")
+          tag_sha=$(jq -r '.object.sha' <<<"$tag_ref")
+          if [[ "$(jq -r '.object.type' <<<"$tag_ref")" == tag ]]; then
+            tag_sha=$(gh api "repos/${GITHUB_REPOSITORY}/git/tags/${tag_sha}" --jq '.object.sha')
+          fi
+          candidate_run=$(gh api --method GET \
+            "repos/${GITHUB_REPOSITORY}/actions/workflows/release-candidate.yml/runs" \
+            -f branch="$RELEASE_TAG" -f event=push -f status=success -f per_page=20 \
+            --jq ".workflow_runs | map(select(.head_sha == \"${tag_sha}\")) | first | .id")
+          if [[ -z "$candidate_run" || "$candidate_run" == null ]]; then
+            echo "no successful release candidate run matches ${RELEASE_TAG}" >&2
+            exit 1
+          fi
+          {
+            echo "tag=${RELEASE_TAG}"
+            echo "version=${version}"
+            echo "run_id=${candidate_run}"
+          } >> "$GITHUB_OUTPUT"
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
         with:
+          ref: ${{ steps.release.outputs.tag }}
           persist-credentials: false
-      - uses: actions/setup-java@be666c2fcd27ec809703dec50e508c2fdc7f6654 # v5
+      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4
         with:
-          distribution: temurin
-          java-version: "21"
-          cache: maven
-          server-id: central
-          server-username: MAVEN_CENTRAL_USERNAME
-          server-password: MAVEN_CENTRAL_PASSWORD
-          gpg-private-key: ${{ secrets.GPG_PRIVATE_KEY }}
-          gpg-passphrase: MAVEN_GPG_PASSPHRASE
-      - name: Publish to Maven Central
+          name: release-candidate-${{ steps.release.outputs.version }}
+          path: candidate
+          repository: ${{ github.repository }}
+          run-id: ${{ steps.release.outputs.run_id }}
+          github-token: ${{ github.token }}
+      - name: Verify candidate integrity
+        shell: bash
+        env:
+          VERSION: ${{ steps.release.outputs.version }}
+        run: |
+          set -euo pipefail
+          (cd candidate && sha256sum --check SHA256SUMS)
+          ./.github/scripts/verify-central-bundle.sh "$VERSION" candidate/central-bundle.zip
+      - name: Publish and verify Maven Central bundle
         shell: bash
         env:
-          MAVEN_CENTRAL_USERNAME: ${{ secrets.MAVEN_CENTRAL_USERNAME }}
           MAVEN_CENTRAL_PASSWORD: ${{ secrets.MAVEN_CENTRAL_PASSWORD }}
-          MAVEN_GPG_PASSPHRASE: ${{ secrets.GPG_PASSPHRASE }}
-        run: mvn -B -Prelease deploy
+          MAVEN_CENTRAL_USERNAME: ${{ secrets.MAVEN_CENTRAL_USERNAME }}
+          VERSION: ${{ steps.release.outputs.version }}
+        run: ./.github/scripts/publish-maven-central.sh "$VERSION" candidate/central-bundle.zip
+      - name: Publish GitHub release
+        env:
+          GH_TOKEN: ${{ github.token }}
+          RELEASE_TAG: ${{ steps.release.outputs.tag }}
+        run: |
+          set -euo pipefail
+          gh release edit "$RELEASE_TAG" --repo "$GITHUB_REPOSITORY" --draft=false --latest
+          if [[ "$(gh api "repos/${GITHUB_REPOSITORY}/releases/tags/${RELEASE_TAG}" --jq '.draft')" != false ]]; then
+            echo "GitHub release is still a draft: ${RELEASE_TAG}" >&2
+            exit 1
+          fi