ci: configure github actions to release docker image

Author: mrsimonemms

Diff for: .github/workflows/release.yml

@@ -0,0 +1,42 @@
+
+name: release
+
+on:
+  push:
+    tags:
+      - "*"
+
+jobs:
+  image:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v2
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and Push Docker Image
+        uses: docker/build-push-action@v2
+        with:
+          push: true
+          tags: |
+            ghcr.io/${{ github.repository }}:${{ github.sha }}
+            ghcr.io/${{ github.repository }}:latest
+
+      - name: Export tgz
+        run: |
+          docker save ghcr.io/${{ github.repository }}:latest | gzip > gitpod-azure-aks-guide.tgz
+
+      - name: Release
+        uses: ncipollo/release-action@v1
+        if: startsWith(github.ref, 'refs/tags/')
+        with:
+          artifacts: gitpod-azure-aks-guide.tgz
+          allowUpdates: true
+          artifactErrorsFailBuild: true
+          token: ${{ secrets.GITHUB_TOKEN }}