feat: build digitalocean images in ci on release

While these don't (yet?) get submitted to the Digitalocean marketplace, it should bring us most of the way of making that possible.

The next step would be to somehow get notifications of the new image snapshot sent... Somewhere and have the lovely DO folks test/release it for us.

.github/workflows/release.yml

@@ -72,6 +72,39 @@ jobs:
           name: build
           path: build
 
+  build-digitalocean:
+    name: build-digitalocean
+    runs-on: ubuntu-20.04
+    needs: release
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: Setup packer
+        uses: hashicorp/setup-packer@main
+        with:
+          version: latest
+
+      - name: Run packer init
+        run: "make image/init/digitalocean"
+
+      - name: Run `packer validate`
+        env:
+          PKR_VAR_dokku_version: ${{ needs.release.outputs.version }}
+        run: "make image/validate/digitalocean"
+
+      - name: Bump Digitalocean Image
+        env:
+          DIGITALOCEAN_TOKEN: ${{ secrets.DIGITALOCEAN_TOKEN }}
+          PKR_VAR_dokku_version: ${{ needs.release.outputs.version }}
+        run: "make image/build/digitalocean"
+
+      - name: upload packages
+        uses: actions/upload-artifact@v3
+        with:
+          name: digitalocean-manifest.json
+          path: digitalocean-manifest.json
+
   bump-azure:
     name: bump-azure
     runs-on: ubuntu-20.04

package.mk

@@ -35,6 +35,11 @@ ifdef DOKKU_GIT_REV
 else
 	git rev-parse HEAD > /tmp/build-dokku/var/lib/dokku/GIT_REV
 endif
+
+.PHONY: image/build/digitalocean
+image/build/digitalocean:
+	packer build -var 'dokku_version=${PKR_VAR_dokku_version}' contrib/images/digitalocean/packer.pkr.hcl
+
 .PHONY: image/init/digitalocean
 image/init/digitalocean:
 	packer init contrib/images/digitalocean/packer.pkr.hcl