Eno Compton and Tyler Bui-Palsulich

16 October 2018

App Engine launched experimental support for Go in 2011. In the subsequent years, the Go community has grown significantly and has settled on idiomatic patterns for cloud-based applications. Today, Google Cloud is announcing a new Go 1.11 runtime for the App Engine standard environment that provides all the power of App Engine—things like paying only for what you use, automatic scaling, and managed infrastructure—while supporting idiomatic Go.

Starting with Go 1.11, Go on App Engine has no limits on application structure, supported packages, context.Context values, or HTTP clients. Write your Go application however you prefer, add an app.yaml file, and your app is ready to deploy on App Engine. Specifying Dependencies describes how the new runtime supports vendoring and modules (experimental) for dependency management.

Along with Cloud Functions support for Go (more on that in a future post), App Engine provides a compelling way to run Go code on Google Cloud Platform (GCP) with no concern for the underlying infrastructure.

Let’s take a look at creating a small application for App Engine. For the example here, we assume a GOPATH -based workflow, although Go modules have experimental support as well.

First, you create the application in your GOPATH :

// This server can run on App Engine. package main import ( "fmt" "log" "net/http" "os" ) func main() { port := os.Getenv("PORT") if port == "" { port = "8080" } http.HandleFunc("/", hello) log.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", port), nil)) } func hello(w http.ResponseWriter, r *http.Request) { w.Write([]byte("Hello, 世界")) }

The code contains an idiomatic setup for a small HTTP server that responds with “Hello, 世界.” If you have previous App Engine experience, you’ll notice the absence of any call to appengine.Main() , which is now entirely optional. Furthermore, the application code is completely portable—there are no ties to the infrastructure that your application is deployed on.

If you need to use external dependencies, you can add those dependencies to a vendor directory or to a go.mod file, both of which the new runtime supports.

With the application code complete, create an app.yaml file to specify the runtime:

runtime: go111

Finally, set your machine up with a Google Cloud Platform account:

Create an account with https://cloud.google.com.

Create a project.

Install the Cloud SDK on your system.

With all the setup complete, you can deploy using one command:

gcloud app deploy

We think Go developers will find the new Go 1.11 runtime for App Engine an exciting addition to the available options to run Go applications. There is a free tier. Check out the getting started guide or the migration guide and deploy an app to the new runtime today!