Refactor container build process to use Docker Buildx and add Dockerfile for multi-stage build

Author: csharpfritz

.github/workflows/container-build.yml

@@ -43,21 +43,17 @@ jobs:
             type=semver,pattern={{version}}
             type=semver,pattern={{major}}.{{minor}}
             type=semver,pattern={{major}}
-            type=sha      
-            
+            type=sha
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
       - name: Build and push container
-        run: |
-          # Create tag arguments for Docker
-          TAGS=""
-          while IFS= read -r tag; do
-            TAGS="$TAGS -t $tag"
-          done <<< "${{ steps.meta.outputs.tags }}"
-          
-          dotnet publish Web/Web.csproj \
-            --os linux \
-            --arch x64 \
-            -c Release \
-            --self-contained \
-            /p:PublishProfile=DefaultContainer \
-            /p:ContainerRepository=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }} \
-            /p:ContainerBuildArgs="$TAGS"
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

Dockerfile

@@ -0,0 +1,23 @@
+# Build stage
+FROM mcr.microsoft.com/dotnet/sdk:9.0 AS build
+WORKDIR /src
+
+# Copy csproj and restore dependencies
+COPY ["Web/Web.csproj", "Web/"]
+RUN dotnet restore "Web/Web.csproj"
+
+# Copy the rest of the source code
+COPY . .
+
+# Build and publish
+RUN dotnet publish "Web/Web.csproj" -c Release -o /app/publish /p:UseAppHost=false
+
+# Runtime stage
+FROM mcr.microsoft.com/dotnet/aspnet:9.0 AS final
+WORKDIR /app
+EXPOSE 80
+EXPOSE 443
+
+# Copy from build stage
+COPY --from=build /app/publish .
+ENTRYPOINT ["dotnet", "Web.dll"]