Apply repo-config migration from 0.16.0 to 0.17.0

.github/workflows/auto-dependabot.yaml

@@ -12,15 +12,18 @@ on:
   pull_request_target:
 
 permissions:
+  # Read repository contents and Dependabot metadata used by the nested action.
   contents: read
+  # The nested action also uses `github.token` internally for PR operations.
   pull-requests: write
 
 jobs:
   auto-merge:
     name: Auto-merge Dependabot PR
     if: >
       github.actor == 'dependabot[bot]' &&
-      !contains(github.event.pull_request.title, 'the repo-config group')
+      !contains(github.event.pull_request.title, 'the repo-config group') &&
+      !contains(github.event.pull_request.title, 'Bump black from ')
     runs-on: ubuntu-slim
     steps:
       - name: Generate GitHub App token
@@ -29,6 +32,12 @@ jobs:
         with:
           app-id: ${{ secrets.FREQUENZ_AUTO_DEPENDABOT_APP_ID }}
           private-key: ${{ secrets.FREQUENZ_AUTO_DEPENDABOT_APP_PRIVATE_KEY }}
+          # Merge Dependabot PRs.
+          permission-contents: write
+          # Create the auto-merged label if it does not exist.
+          permission-issues: write
+          # Approve PRs, add labels, and enable auto-merge.
+          permission-pull-requests: write
 
       - name: Auto-merge Dependabot PR
         uses: frequenz-floss/dependabot-auto-approve@e943399cc9d76fbb6d7faae446cd57301d110165 # v1.5.0

.github/workflows/black-migration.yaml

@@ -0,0 +1,88 @@
+# Automatic black formatting migration for Dependabot PRs
+#
+# When Dependabot upgrades black, this workflow installs the new version
+# and runs `black .` so the PR already contains any formatting changes
+# introduced by the upgrade, while leaving the PR open for review.
+#
+# Black uses calendar versioning.  Only the first release of a new calendar
+# year may introduce formatting changes (major bump in Dependabot's terms).
+# Minor and patch updates within a year keep formatting stable, so they stay
+# in the regular Dependabot groups and are auto-merged normally.
+#
+# The companion auto-dependabot workflow skips major black PRs so they're
+# handled exclusively by this migration workflow.
+#
+# XXX: !!! SECURITY WARNING !!!
+# pull_request_target has write access to the repo, and can read secrets.
+# This is required because Dependabot PRs are treated as fork PRs: the
+# GITHUB_TOKEN is read-only and secrets are unavailable with a plain
+# pull_request trigger.  The action mitigates the risk by:
+#   - Never executing code from the PR (the migration script is embedded
+#     in this workflow file on the base branch, not taken from the PR).
+#   - Gating migration steps on github.actor == 'dependabot[bot]'.
+#   - Running checkout with persist-credentials: false and isolating
+#     push credentials from the migration script environment.
+# For more details read:
+# https://securitylab.github.com/research/github-actions-preventing-pwn-requests/
+
+name: Black Migration
+
+on:
+  merge_group:  # To allow using this as a required check for merging
+  pull_request_target:
+    types: [opened, synchronize, reopened, labeled, unlabeled]
+
+permissions:
+  # Commit reformatted files back to the PR branch.
+  contents: write
+  # Create and normalize migration state labels.
+  issues: write
+  # Read/update pull request metadata and comments.
+  pull-requests: write
+
+jobs:
+  black-migration:
+    name: Migrate Black
+    # Skip if it was triggered by the merge queue. We only need the workflow to
+    # be executed to meet the "Required check" condition for merging, but we
+    # don't need to actually run the job, having the job present as Skipped is
+    # enough.
+    if: |
+      github.event_name == 'pull_request_target' &&
+      github.actor == 'dependabot[bot]' &&
+      contains(github.event.pull_request.title, 'Bump black from ')
+    runs-on: ubuntu-24.04
+    steps:
+      - name: Generate token
+        id: create-app-token
+        uses: actions/create-github-app-token@f8d387b68d61c58ab83c6c016672934102569859 # v3.0.0
+        with:
+          app-id: ${{ secrets.FREQUENZ_AUTO_DEPENDABOT_APP_ID }}
+          private-key: ${{ secrets.FREQUENZ_AUTO_DEPENDABOT_APP_PRIVATE_KEY }}
+          # Push reformatted files to the PR branch.
+          permission-contents: write
+          # Create and normalize migration state labels.
+          permission-issues: write
+          # Read/update pull request metadata and labels.
+          permission-pull-requests: write
+      - name: Migrate
+        uses: frequenz-floss/gh-action-dependabot-migrate@b389f72f9282346920150a67495efbae450ac07b  # v1.1.0
+        with:
+          migration-script: |
+            import os
+            import subprocess
+            import sys
+
+            version = os.environ["MIGRATION_VERSION"].lstrip("v")
+            subprocess.run(
+                [sys.executable, "-Im", "pip", "install", f"black=={version}"],
+                check=True,
+            )
+            subprocess.run([sys.executable, "-Im", "black", "."], check=True)
+          token: ${{ steps.create-app-token.outputs.token }}
+          auto-merge-on-changes: "false"
+          sign-commits: "true"
+          auto-merged-label: "tool:auto-merged"
+          migrated-label: "tool:black:migration:executed"
+          intervention-pending-label: "tool:black:migration:intervention-pending"
+          intervention-done-label: "tool:black:migration:intervention-done"

.github/workflows/ci-pr.yaml

@@ -3,6 +3,10 @@ name: Test PR
 on:
   pull_request:
 
+permissions:
+  # Read repository contents for checkout and dependency resolution only.
+  contents: read
+
 env:
   # Please make sure this version is included in the `matrix`, as the
   # `matrix` section can't use `env`, so it must be entered manually
@@ -17,7 +21,7 @@ jobs:
 
     steps:
       - name: Run nox
-        uses: frequenz-floss/gh-action-nox@v1.1.1
+        uses: frequenz-floss/gh-action-nox@e1351cf45e05e85afc1c79ab883e06322892d34c # v1.1.0
         with:
           python-version: "3.11"
           nox-session: ci_checks_max
@@ -27,15 +31,15 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Setup Git
-        uses: frequenz-floss/gh-action-setup-git@v1.0.0
+        uses: frequenz-floss/gh-action-setup-git@16952aac3ccc01d27412fe0dea3ea946530dcace # v1.0.0
 
       - name: Fetch sources
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           submodules: true
 
       - name: Setup Python
-        uses: frequenz-floss/gh-action-setup-python-with-deps@v1.0.4
+        uses: frequenz-floss/gh-action-setup-python-with-deps@0d0d77eac3b54799f31f25a1060ef2c6ebdf9299 # v1.0.2
         with:
           python-version: ${{ env.DEFAULT_PYTHON_VERSION }}
           dependencies: .[dev-mkdocs]
@@ -44,11 +48,14 @@ jobs:
         env:
           MIKE_VERSION: gh-${{ github.job }}
         run: |
-          mike deploy $MIKE_VERSION
-          mike set-default $MIKE_VERSION
+          # mike is installed as a console script, not a runnable module.
+          # Run the installed script under isolated mode to avoid importing from
+          # the workspace when building docs from checked-out code.
+          python -I "$(command -v mike)" deploy "$MIKE_VERSION"
+          python -I "$(command -v mike)" set-default "$MIKE_VERSION"
 
       - name: Upload site
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
         with:
           name: docs-site
           path: site/