From 95460489b3ce533b05aefe33c95e39a43a536b16 Mon Sep 17 00:00:00 2001
From: Alexander Entinger <consulting@lxrobotics.com>
Date: Tue, 7 Mar 2023 14:36:12 +0100
Subject: [PATCH] Add CI workflow to synchronize with shared repository labels

On every push that changes relevant files, and periodically, configure the repository's issue and pull request labels
according to the universal, shared, and local label configuration files.
---
 .github/workflows/sync-labels.yml | 138 ++++++++++++++++++++++++++++++
 README.md                         |   2 +-
 2 files changed, 139 insertions(+), 1 deletion(-)
 create mode 100644 .github/workflows/sync-labels.yml

diff --git a/.github/workflows/sync-labels.yml b/.github/workflows/sync-labels.yml
new file mode 100644
index 0000000..63c5b72
--- /dev/null
+++ b/.github/workflows/sync-labels.yml
@@ -0,0 +1,138 @@
+# Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/sync-labels.md
+name: Sync Labels
+
+# See: https://docs.github.com/actions/using-workflows/events-that-trigger-workflows
+on:
+  push:
+    paths:
+      - ".github/workflows/sync-labels.ya?ml"
+      - ".github/label-configuration-files/*.ya?ml"
+  pull_request:
+    paths:
+      - ".github/workflows/sync-labels.ya?ml"
+      - ".github/label-configuration-files/*.ya?ml"
+  schedule:
+    # Run daily at 8 AM UTC to sync with changes to shared label configurations.
+    - cron: "0 8 * * *"
+  workflow_dispatch:
+  repository_dispatch:
+
+env:
+  CONFIGURATIONS_FOLDER: .github/label-configuration-files
+  CONFIGURATIONS_ARTIFACT: label-configuration-files
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Download JSON schema for labels configuration file
+        id: download-schema
+        uses: carlosperate/download-file-action@v2
+        with:
+          file-url: https://raw.githubusercontent.com/arduino/tooling-project-assets/main/workflow-templates/assets/sync-labels/arduino-tooling-gh-label-configuration-schema.json
+          location: ${{ runner.temp }}/label-configuration-schema
+
+      - name: Install JSON schema validator
+        run: |
+          sudo npm install \
+            --global \
+            ajv-cli \
+            ajv-formats
+
+      - name: Validate local labels configuration
+        run: |
+          # See: https://github.com/ajv-validator/ajv-cli#readme
+          ajv validate \
+            --all-errors \
+            -c ajv-formats \
+            -s "${{ steps.download-schema.outputs.file-path }}" \
+            -d "${{ env.CONFIGURATIONS_FOLDER }}/*.{yml,yaml}"
+
+  download:
+    needs: check
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        filename:
+          # Filenames of the shared configurations to apply to the repository in addition to the local configuration.
+          # https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/sync-labels
+          - universal.yml
+
+    steps:
+      - name: Download
+        uses: carlosperate/download-file-action@v2
+        with:
+          file-url: https://raw.githubusercontent.com/arduino/tooling-project-assets/main/workflow-templates/assets/sync-labels/${{ matrix.filename }}
+
+      - name: Pass configuration files to next job via workflow artifact
+        uses: actions/upload-artifact@v3
+        with:
+          path: |
+            *.yaml
+            *.yml
+          if-no-files-found: error
+          name: ${{ env.CONFIGURATIONS_ARTIFACT }}
+
+  sync:
+    needs: download
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Set environment variables
+        run: |
+          # See: https://docs.github.com/actions/using-workflows/workflow-commands-for-github-actions#setting-an-environment-variable
+          echo "MERGED_CONFIGURATION_PATH=${{ runner.temp }}/labels.yml" >> "$GITHUB_ENV"
+
+      - name: Determine whether to dry run
+        id: dry-run
+        if: >
+          github.event_name == 'pull_request' ||
+          (
+            (
+              github.event_name == 'push' ||
+              github.event_name == 'workflow_dispatch'
+            ) &&
+            github.ref != format('refs/heads/{0}', github.event.repository.default_branch)
+          )
+        run: |
+          # Use of this flag in the github-label-sync command will cause it to only check the validity of the
+          # configuration.
+          echo "flag=--dry-run" >> $GITHUB_OUTPUT
+
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Download configuration files artifact
+        uses: actions/download-artifact@v3
+        with:
+          name: ${{ env.CONFIGURATIONS_ARTIFACT }}
+          path: ${{ env.CONFIGURATIONS_FOLDER }}
+
+      - name: Remove unneeded artifact
+        uses: geekyeggo/delete-artifact@v2
+        with:
+          name: ${{ env.CONFIGURATIONS_ARTIFACT }}
+
+      - name: Merge label configuration files
+        run: |
+          # Merge all configuration files
+          shopt -s extglob
+          cat "${{ env.CONFIGURATIONS_FOLDER }}"/*.@(yml|yaml) > "${{ env.MERGED_CONFIGURATION_PATH }}"
+
+      - name: Install github-label-sync
+        run: sudo npm install --global github-label-sync
+
+      - name: Sync labels
+        env:
+          GITHUB_ACCESS_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          # See: https://github.com/Financial-Times/github-label-sync
+          github-label-sync \
+            --labels "${{ env.MERGED_CONFIGURATION_PATH }}" \
+            ${{ steps.dry-run.outputs.flag }} \
+            ${{ github.repository }}
diff --git a/README.md b/README.md
index dc52f6f..93dedf4 100644
--- a/README.md
+++ b/README.md
@@ -2,8 +2,8 @@
 
 `USBHostMbed5`
 ==============
-
 [![Spell Check status](https://github.com/facchinm/USBHostMbed5/actions/workflows/spell-check.yml/badge.svg)](https://github.com/facchinm/USBHostMbed5/actions/workflows/spell-check.yml)
+[![Sync Labels status](https://github.com/facchinm/USBHostMbed5/actions/workflows/sync-labels.yml/badge.svg)](https://github.com/facchinm/USBHostMbed5/actions/workflows/sync-labels.yml)
 
 ARM Mbed5 USB Host library ported for [ArduinoCore-mbed](https://github.com/arduino/ArduinoCore-mbed) enabled boards.