add dockerfile + gh action

.github/workflows/service-extensions-publish.yml

@@ -0,0 +1,38 @@
+name: Publish Service Extensions Callout images packages
+
+# on push in the PR branch
+on:
+  push:
+    branches:
+      - 'flavien/service-extensions'
+
+jobs:
+  publish-service-extensions:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up Go 1.22
+        uses: actions/setup-go@v2
+        with:
+          go-version: 1.22
+        id: go
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Docker
+        shell: bash
+        run: docker login -u publisher -p ${{ secrets.GITHUB_TOKEN }} ghcr.io
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ./contrib/envoyproxy/envoy/cmd/serviceextensions/Dockerfile
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: ${{ github.repository_owner }}/service-extensions-callout:latest
+
+

contrib/envoyproxy/envoy/cmd/serviceextensions/Dockerfile

@@ -0,0 +1,15 @@
+# Build stage
+FROM golang:1.22-alpine AS builder
+WORKDIR /app
+COPY . .
+RUN go build -o serviceextensions ./contrib/envoyproxy/envoy/cmd/serviceextensions
+
+# Runtime stage
+FROM alpine:3.20.3
+WORKDIR /app
+COPY --from=builder /app/contrib/envoyproxy/envoy/cmd/serviceextensions/serviceextensions /app/serviceextensions
+
+EXPOSE 80
+EXPOSE 443
+
+CMD ["./serviceextensions"]