first version of docker build workflow

.github/workflows/docker.yaml

@@ -0,0 +1,45 @@
+name: Build Docker
+
+on:
+  push:
+    branches:
+      - 'main'
+    paths:
+      - ".devcontainer/Dockerfile"
+  workflow_dispatch:
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-docker:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      -
+        name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+              # set latest tag for default branch
+              type=raw,value=latest,enable={{is_default_branch}}
+      - name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          push: true
+          context: .devcontainer/
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}