STAC-25509 Fix scheduled dependency update blocked by the Actions allowlist

.github/scripts/open-signed-pr.sh

@@ -0,0 +1,141 @@
+#!/usr/bin/env bash
+#
+# Open (or refresh) a pull request whose commit is signed by GitHub.
+#
+# Why this exists rather than an off-the-shelf action: master requires signed
+# commits, and StackVista's Actions allowlist does not include the usual
+# create-pull-request action. The GraphQL createCommitOnBranch mutation is the
+# only way to have GitHub sign a commit made on behalf of a token, so the
+# branch, the commit and the PR are all created through the API here.
+#
+# Everything is driven by environment variables so no caller input is
+# interpolated into this script:
+#
+#   GH_TOKEN       GitHub App installation token (contents:write, pull-requests:write)
+#   GH_REPO        owner/name
+#   BASE_BRANCH    branch the PR merges into
+#   HEAD_BRANCH    working branch to create
+#   COMMIT_MESSAGE headline of the commit
+#   PR_TITLE       pull request title
+#   PR_BODY        pull request body
+#
+# Reads the working tree for changes relative to HEAD; exits 0 without doing
+# anything if there are none.
+
+set -euo pipefail
+
+for var in GH_TOKEN GH_REPO BASE_BRANCH HEAD_BRANCH COMMIT_MESSAGE PR_TITLE PR_BODY; do
+  if [ -z "${!var:-}" ]; then
+    echo "::error::open-signed-pr: missing required environment variable: ${var}" >&2
+    exit 1
+  fi
+done
+
+BASE_SHA=$(git rev-parse HEAD)
+
+# Files the updater touched, split into content changes and removals. The
+# lowercase 'd' filter means "everything except deletions". git diff only ever
+# reports tracked paths, so brand new files are collected separately -
+# otherwise they would be dropped from the commit without any warning.
+mapfile -t changed_files < <(
+  {
+    git diff --name-only --diff-filter=d
+    git ls-files --others --exclude-standard
+  } | sort -u
+)
+mapfile -t deleted_files < <(git diff --name-only --diff-filter=D)
+
+if [ ${#changed_files[@]} -eq 0 ] && [ ${#deleted_files[@]} -eq 0 ]; then
+  echo "No changes in the working tree; nothing to open."
+  exit 0
+fi
+
+echo "Changed: ${changed_files[*]:-none}"
+echo "Deleted: ${deleted_files[*]:-none}"
+
+# File contents must never travel through argv. Linux caps a single argument
+# at 128 KiB (MAX_ARG_STRLEN), and go.sum alone is well past that once base64
+# encoded, so `jq --arg contents "$(base64 ...)"` dies with E2BIG. Everything
+# that can grow is handed to jq through files instead: --rawfile to read the
+# encoded blob, --slurpfile to read the assembled arrays.
+work=$(mktemp -d)
+trap 'rm -rf "${work}"' EXIT
+
+additions="${work}/additions.json"
+echo '[]' > "${additions}"
+if [ ${#changed_files[@]} -gt 0 ]; then
+  : > "${work}/additions.ndjson"
+  for f in "${changed_files[@]}"; do
+    base64 -w0 "$f" > "${work}/content.b64"
+    # base64 -w0 still terminates with a newline; GitHub wants the bare blob.
+    jq -n --arg path "$f" --rawfile contents "${work}/content.b64" \
+      '{path: $path, contents: ($contents | rtrimstr("\n"))}' >> "${work}/additions.ndjson"
+  done
+  jq -s '.' "${work}/additions.ndjson" > "${additions}"
+fi
+
+deletions="${work}/deletions.json"
+echo '[]' > "${deletions}"
+if [ ${#deleted_files[@]} -gt 0 ]; then
+  printf '%s\n' "${deleted_files[@]}" | jq -R '{path: .}' | jq -s '.' > "${deletions}"
+fi
+
+# Point the working branch at the commit we built from. Creating the commit
+# with expectedHeadOid equal to this SHA then fails loudly if anything else
+# moved the branch in between.
+if gh api "repos/${GH_REPO}/git/ref/heads/${HEAD_BRANCH}" >/dev/null 2>&1; then
+  echo "Branch ${HEAD_BRANCH} exists; resetting it to ${BASE_SHA}."
+  gh api --method PATCH "repos/${GH_REPO}/git/refs/heads/${HEAD_BRANCH}" \
+    -F sha="${BASE_SHA}" -F force=true >/dev/null
+else
+  echo "Creating branch ${HEAD_BRANCH} at ${BASE_SHA}."
+  gh api --method POST "repos/${GH_REPO}/git/refs" \
+    -f ref="refs/heads/${HEAD_BRANCH}" -F sha="${BASE_SHA}" >/dev/null
+fi
+
+payload="${work}/payload.json"
+
+jq -n \
+  --arg repo "${GH_REPO}" \
+  --arg branch "${HEAD_BRANCH}" \
+  --arg message "${COMMIT_MESSAGE}" \
+  --arg oid "${BASE_SHA}" \
+  --slurpfile additions "${additions}" \
+  --slurpfile deletions "${deletions}" \
+  '{
+     query: "mutation($input: CreateCommitOnBranchInput!) { createCommitOnBranch(input: $input) { commit { oid url } } }",
+     variables: {
+       input: {
+         branch: {
+           repositoryNameWithOwner: $repo,
+           branchName: $branch
+         },
+         message: { headline: $message },
+         expectedHeadOid: $oid,
+         fileChanges: {
+           additions: $additions[0],
+           deletions: $deletions[0]
+         }
+       }
+     }
+   }' > "${payload}"
+
+echo "Creating signed commit on ${HEAD_BRANCH}."
+commit_url=$(gh api graphql --input "${payload}" --jq '.data.createCommitOnBranch.commit.url')
+echo "Commit: ${commit_url}"
+
+existing=$(gh pr list --repo "${GH_REPO}" --head "${HEAD_BRANCH}" --state open --json url --jq '.[0].url // empty')
+if [ -n "${existing}" ]; then
+  echo "Pull request already open, refreshed in place: ${existing}"
+  gh pr edit "${existing}" --repo "${GH_REPO}" --title "${PR_TITLE}" --body "${PR_BODY}" >/dev/null
+  echo "pr_url=${existing}" >> "${GITHUB_OUTPUT:-/dev/null}"
+  exit 0
+fi
+
+pr_url=$(gh pr create --repo "${GH_REPO}" \
+  --base "${BASE_BRANCH}" \
+  --head "${HEAD_BRANCH}" \
+  --title "${PR_TITLE}" \
+  --body "${PR_BODY}")
+echo "Pull request: ${pr_url}"
+echo "pr_url=${pr_url}" >> "${GITHUB_OUTPUT:-/dev/null}"

.github/workflows/update-datadog-dependency.yml

@@ -12,19 +12,37 @@ on:
         default: 'stackstate-7.62.2'
 
 permissions:
-  contents: write
-  pull-requests: write
+  # All write auth below uses a short-lived GitHub App installation token.
+  # The default GITHUB_TOKEN stays read-only on purpose: events raised with it
+  # are subject to GitHub's recursion-prevention rule, so a PR it opened would
+  # never trigger the required "Process-agent CI" check and could not merge.
+  contents: read
+
+concurrency:
+  # Two scheduled/dispatched runs must not race on the same working branch.
+  group: update-datadog-dependency
+  cancel-in-progress: false
 
 jobs:
   update-dependency:
     runs-on: ubuntu-latest
     steps:
+      - name: Create updatecli GitHub App token
+        id: app-token
+        uses: actions/create-github-app-token@bcd2ba49218906704ab6c1aa796996da409d3eb1 # v3
+        with:
+          client-id: ${{ vars.UPDATECLI_GH_APP_CLIENT_ID }}
+          private-key: ${{ secrets.UPDATECLI_GH_APP_PRIVATE_KEY }}
+          permission-contents: write
+          permission-pull-requests: write
+          repositories: stackstate-process-agent
+
       - name: Checkout repository
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           fetch-depth: 0
-          # No later step pushes via git: the updater only reads, and
-          # create-pull-request authenticates with its own token input
+          # Nothing here pushes over git: the branch, the commit and the PR are
+          # all created through the API using the App token.
           persist-credentials: false
 
       - name: Setup Go
@@ -79,13 +97,20 @@ jobs:
 
       - name: Create pull request if changes detected
         if: steps.update.outputs.changed == 'true'
-        uses: peter-evans/create-pull-request@271a8d0340265f705b14b6d32b9829c1cb33d45e # v7.0.8
-        with:
-          title: |
-            chore: update datadog-agent upstream (${{ steps.update.outputs.branch }}) -> ${{ steps.update.outputs.short_commit }}
-          commit-message: |
-            chore: update datadog-agent upstream to ${{ steps.update.outputs.commit }} (branch ${{ steps.update.outputs.branch }})
-          body: |
+        env:
+          GH_TOKEN: ${{ steps.app-token.outputs.token }}
+          GH_REPO: ${{ github.repository }}
+          BASE_BRANCH: ${{ github.ref_name }}
+          HEAD_BRANCH: update-datadog-${{ steps.update.outputs.short_commit }}
+          COMMIT_MESSAGE: >-
+            chore: update datadog-agent upstream to
+            ${{ steps.update.outputs.commit }}
+            (branch ${{ steps.update.outputs.branch }})
+          PR_TITLE: >-
+            chore: update datadog-agent upstream
+            (${{ steps.update.outputs.branch }}) ->
+            ${{ steps.update.outputs.short_commit }}
+          PR_BODY: |
             This automated PR updates all github.com/DataDog/datadog-agent module replaces to the upstream mirror at the latest commit.
 
             • Branch: `${{ steps.update.outputs.branch }}`
@@ -96,11 +121,9 @@ jobs:
             `./update-datadog-dependency.sh -b "${{ steps.update.outputs.branch }}"`
 
             Re-run this workflow with a different `upstream_branch` to refresh the PR.
-          branch: update-datadog-${{ steps.update.outputs.short_commit }}
-          delete-branch: true
-          # master requires signed commits (pulumi-infra branch protection);
-          # sign-commits creates the commit via the GitHub API so it is verified
-          sign-commits: true
+        run: |
+          chmod +x .github/scripts/open-signed-pr.sh
+          .github/scripts/open-signed-pr.sh
 
       - name: No updates needed
         if: steps.update.outputs.changed != 'true'