add docker build pipeline

.github/workflows/docker-publish.yml

@@ -0,0 +1,68 @@
+name: Build & Publish Docker image to Docker Hub
+
+on:
+  push:
+    branches: [ "main" ]
+    tags:
+      - "v*"
+  workflow_dispatch:
+
+concurrency:
+  group: docker-publish-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  # Change this if your Docker Hub namespace differs from your username
+  DOCKERHUB_NAMESPACE: ${{ secrets.DOCKERHUB_USERNAME }}
+  IMAGE_NAME: vrc-ytdlp-resolver
+  PLATFORMS: linux/amd64,linux/arm64
+
+jobs:
+  docker:
+    name: Build & Push
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Extract Docker metadata (tags, labels)
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.DOCKERHUB_NAMESPACE }}/${{ env.IMAGE_NAME }}
+          tags: |
+            # latest for main branch
+            type=raw,value=latest,enable={{is_default_branch}}
+            # git sha
+            type=sha
+            # semver tags like v1.2.3 -> 1.2.3, 1.2, 1
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+
+      - name: Build & Push (multi-arch)
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ./Dockerfile
+          push: true
+          platforms: ${{ env.PLATFORMS }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max