Europa: integrate core packages, separate universe

Signed-off-by: Solomon Hykes <solomon@dagger.io>

europa-universe/examples/todoapp/dev/dev.cue

@@ -0,0 +1,40 @@
+// Local dev environment for todoapp
+package todoapp
+
+import (
+	"universe.dagger.io/docker"
+	"universe.dagger.io/nginx"
+)
+
+// Expose todoapp web port
+proxy: web: _
+
+actions: {
+	// Reference app build inherited from base config
+	build: _
+	_app:  build.output
+
+	container: {
+		// Build a container image serving the app with nginx
+		build: docker.#Build & {
+			steps: [
+				nginx.#Build & {
+					flavor: "alpine"
+				},
+				docker.#Copy & {
+					contents: _app
+					dest:     "/usr/share/nginx/html"
+				},
+			]
+		}
+
+		// Run the app in an ephemeral container
+		run: docker.#Run & {
+			image: build.output
+			ports: web: {
+				frontend: proxy.web.endpoint
+				backend: address: "localhost:5000"
+			}
+		}
+	}
+}