feat(plugins): add Caddy reverse proxy integration

.github/workflows/plugins.yml

@@ -89,7 +89,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        provider: [docker_classic, docker_swarm, kubernetes]
+        provider: [docker, docker_swarm] # , kubernetes]
     steps:
       - name: Set up Go 1.18
         uses: actions/setup-go@v2
@@ -115,4 +115,71 @@ jobs:
         run: docker load --input /tmp/sablier.tar
 
       - name: Test ${{ matrix.provider }}
-        run: cd plugins/nginx/e2e && bash ./${{ matrix.provider }}.sh
+        run: cd plugins/nginx/e2e && bash ./${{ matrix.provider }}.sh
+
+  build-caddy:
+    name: Build Caddy docker image once and share it to Caddy E2E jobs
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          context: plugins/caddy
+          file: plugins/caddy/Dockerfile
+          tags: caddy:local
+          outputs: type=docker,dest=/tmp/caddy.tar
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: caddy-image-tar
+          path: /tmp/caddy.tar
+
+  caddy_e2e:
+    name: Run Sablier E2E tests for Caddy middleware
+    runs-on: ubuntu-latest
+    needs: 
+      - build
+      - build-caddy
+    strategy:
+      fail-fast: false
+      matrix:
+        provider: [docker, docker_swarm] # , kubernetes]
+    steps:
+      - name: Set up Go 1.18
+        uses: actions/setup-go@v2
+        with:
+          go-version: 1.18
+
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+
+      - name: Download artifact
+        uses: actions/download-artifact@v2
+        with:
+          name: sablier-image-tar
+          path: /tmp
+          
+      - name: Load Docker image
+        run: docker load --input /tmp/sablier.tar
+
+      - name: Download Caddy artifact
+        uses: actions/download-artifact@v2
+        with:
+          name: caddy-image-tar
+          path: /tmp
+          
+      - name: Load Caddy Docker image
+        run: docker load --input /tmp/caddy.tar
+
+      - name: Test ${{ matrix.provider }}
+        run: cd plugins/caddy/e2e && bash ./${{ matrix.provider }}.sh