Publish a Docker image to GHCR on every release

.github/workflows/publish-ghcr.yml

@@ -0,0 +1,35 @@
+name: Publish Docker image to GHCR
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: ./Dockerfile
+          push: true
+          tags: |
+            ghcr.io/platformsh/upsun-cli:${{ github.event.release.tag_name }}
+            ghcr.io/platformsh/upsun-cli:latest

Dockerfile

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+FROM ubuntu:24.04
+
+# Install dependencies
+RUN apt-get update && \
+    apt-get install -y curl bash git ssh-client && \
+    rm -rf /var/lib/apt/lists/*
+
+# Install Upsun CLI
+ARG VERSION=
+RUN curl -fsSL https://raw.githubusercontent.com/platformsh/cli/main/installer.sh | VENDOR=upsun INSTALL_METHOD=raw VERSION=$VERSION bash
+
+# Default command
+ENTRYPOINT ["upsun"]