Add CI with GitHub Actions

.github/workflows/release.yml

@@ -0,0 +1,48 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - "*"
+
+jobs:
+  docker:
+    runs-on: ubuntu-20.04
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          token: ${{ secrets.API_GITHUB_TOKEN }}
+
+      - name: Docker meta
+        id: docker_meta
+        uses: crazy-max/ghaction-docker-meta@v2
+        with:
+          images: juanluisbaptiste/postfix
+          tags: |
+            type=semver,pattern={{major}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}.{{minor}}.{{patch}}
+            type=semver,pattern={{version}}
+            alpine
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          push: true
+          platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64
+          tags: ${{ steps.docker_meta.outputs.tags }}
+          labels: ${{ steps.docker_meta.outputs.labels }}