[ci] Attempt to move to reusable workflows

.github/workflows/build.yml

@@ -0,0 +1,41 @@
+name: Build Docker Image
+
+on:
+  workflow_call:
+    inputs:
+      arch:
+        required: true
+        type: string
+
+jobs:
+  docker:
+    name: Build Docker image 
+    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: Login to Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ${{ secrets.REGISTRY_URL }}
+          username: ${{ secrets.REGISTRY_USERNAME }}
+          password: ${{ secrets.REGISTRY_PASSWORD }}
+      -
+        name: Get short commit SHA
+        id: commit_sha
+        run: echo "::set-output name=sha_short::$(git rev-parse --short HEAD)"
+      -
+        name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          platforms: linux/${{ inputs.arch }}
+          push: ${{ github.ref == 'refs/heads/dev' }}
+          tags: ${{ secrets.REGISTRY_URL }}/west/telegram-bot:latest,
+              ${{ secrets.REGISTRY_URL }}/west/telegram-bot:${{ steps.commit_sha.outputs.sha_short }}