Added Dockerfile

.github/workflows/docker.yml

@@ -0,0 +1,64 @@
+---
+name: docker
+
+on:
+  schedule:
+    - cron: 0 14 * * 0    # every sunday at 14:00
+  push:
+    branches:
+      - '**'
+    tags:
+      - '*.*.*'
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Set up dynamic build ARGs
+        id: getargs
+        run: echo "::set-output name=version::$(cat ./stable/VERSION)"
+
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v3
+        with:
+          # list of Docker images to use as base name for tags
+          images: |
+            jokobsk/pi.alert
+          # generate Docker tags based on the following events/attributes
+          tags: |
+            type=raw,value=latest
+            type=schedule
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+            type=sha
+
+      - name: Login to DockerHub
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          platforms: linux/amd64,linux/arm64,linux/arm/v7
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}