From 03c07b170bdd301a8f20bae0f22dc1776ddc2f1f Mon Sep 17 00:00:00 2001
From: Ewoud Kohl van Wijngaarden <ewoud@kohlvanwijngaarden.nl>
Date: Tue, 13 Jul 2021 18:56:19 +0200
Subject: [PATCH] Add a job to warn about modulesync changes

01cfc20164bb4db5432b82d7a59e2227a718b240 added headers, but this isn't
really a good experience for users. It's actually much better to fail in
CI if a diff is detected. That gives them also a way to verify their
changes to .sync.yml are correct.

This takes the approach of checking out the modulesync config with the
version from .msync.yml and running a one off change in offline mode.
Then it uses git diff to see if there are differences. That should fail
the build and also show the actual differences, which makes debugging
easier.
---
 .../.github/workflows/modulesync.yml.erb      | 52 +++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 moduleroot/.github/workflows/modulesync.yml.erb

diff --git a/moduleroot/.github/workflows/modulesync.yml.erb b/moduleroot/.github/workflows/modulesync.yml.erb
new file mode 100644
index 00000000..bb62fe92
--- /dev/null
+++ b/moduleroot/.github/workflows/modulesync.yml.erb
@@ -0,0 +1,52 @@
+---
+# Managed by modulesync - DO NOT EDIT
+# https://voxpupuli.org/docs/updating-files-managed-with-modulesync/
+
+name: Modulesync
+
+on: pull_request
+
+jobs:
+  compare_with_repo:
+    name: 'Compare with config'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Puppet module repository
+        uses: actions/checkout@v2
+        with:
+          path: modules/${{ github.repository }}
+
+      - name: Setup ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: '3.0'
+
+      - name: Set modulesync version
+        run: ruby -ryaml -e 'puts "MSYNC_VER=#{YAML.safe_load(File.read(".msync.yml"))["modulesync_config_version"]}"' >> $GITHUB_ENV
+        working-directory: modules/${{ github.repository }}
+
+      - name: Checkout modulesync configuration repository
+        uses: actions/checkout@v2
+        with:
+          # TODO: is there a modulesync variable for this?
+          repository: voxpupuli/modulesync_config
+          ref: ${{ env.MSYNC_VER }}
+          path: msync_config
+
+      - name: Create a temporary managed modules file
+        run: echo "- $GITHUB_REPOSITORY" > msync_config/pr-managed-modules.yaml
+
+      - name: Setup ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: '3.0'
+          bundler-cache: true
+          working-directory: msync_config
+
+      - name: Run modulesync
+        run: bundle exec msync update --offline --managed-modules-conf=pr-managed-modules.yaml --project-root=../modules
+        working-directory: msync_config
+
+      - name: Check for differences
+        run: git diff --exit-code
+        working-directory: modules/${{ github.repository }}