Upload docker images to ghcr.io after release

Author: sgillespie

.github/workflows/release-ghcr.yml

@@ -0,0 +1,47 @@
+name: Push Image to ghcr.io
+
+on:
+  release:
+    types:
+      - published
+  push:
+    tags:
+      - '**'
+
+env:
+  REGISTRY: ghcr.io
+
+jobs:
+  build:
+    name: "Upload to ghcr.io"
+    runs-on: ubuntu-latest
+    steps:
+      - name: Install Nix with good defaults
+        uses: input-output-hk/install-nix-action@v21
+        with:
+          extra_nix_config: |
+            trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ=
+            substituters = https://cache.iog.io/ https://cache.nixos.org/
+          nix_path: nixpkgs=channel:nixos-unstable
+
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Download image from cache
+        run:
+          nix build --builders "" --max-jobs 0 .#dockerImage -o dockerImage
+
+      - name: Log in to ghcr.io
+        uses: docker/[email protected]
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Upload to ghcr.io
+        run: |
+          docker load < dockerImage
+          docker image tag \
+            inputoutput/cardano-db-sync:$GITHUB_SHA  \
+            ghcr.io/${{ github.repository_owner }}/cardano-db-sync:$GITHUB_REF_NAME
+          docker push ghcr.io/${{ github.repository_owner }}/cardano-db-sync:$GITHUB_REF_NAME