Add CI to check that we can build the production site

Signed-off-by: Robert Young <[email protected]>

Author: robobario

.github/workflows/pr-build.yml

@@ -0,0 +1,42 @@
+# Sample workflow for building and deploying a Jekyll site to GitHub Pages
+name: Test PR
+
+on:
+  pull_request:
+    types: [ opened, synchronize, reopened ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    services:
+      registry:
+        image: registry:2
+        ports:
+          - 5000:5000
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+        with:
+          # this is required for the subsequent build to be able to push to the registry on localhost:5000
+          driver-opts: network=host
+
+      - name: Build Docker image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          tags: localhost:5000/kroxy-jekyll:latest
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+ 
+      - name: Build with Jekyll
+        run: |
+          docker run \
+            --rm \
+            -u "$(id -u):$(id -g)" \
+            -v "$(pwd):/site" \
+            localhost:5000/kroxy-jekyll:latest \
+            bash -c 'eval "$(rbenv init -)" && cp -r /css/_sass/bootstrap /site/_sass/ && JEKYLL_ENV=production bundle exec jekyll build --config=_config.yml'