AppEngine/Go: Using a new version of Go with the SDK

Question

The Go SDK currently ships with Go version is 1.6.2 but the most recent is 1.7.1 . I need some enhancements/bugfixes that were released since 1.6.2 . However, when I replace the goroot directory in the SDK directory that contains Go 1.6.2 with a symlink that points to 1.7.1, I get an error that has to do with not being able to find bin/goapp , which looks to be AppEngine-specific and not provided in the standard Go build.

Does anyone know a way to upgrade the Go available in the AppEngine SDK? Does this mean that the Go in production is also 1.6.2?

Answer 1

Unfortunately you're stuck with the Go version that comes bundled in the latest App Engine Go SDK.

Even if you "switch" it locally with Go 1.7.1 and somehow you manage to compile and run your app with Go 1.7.1 (by adding the missing files from the SDK's Go root), the production environment currently also uses Go 1.6.2, so your app and Go code will run into errors in the live environment when code that is missing from 1.6.2 is referenced. Most likely even the deployment would fail.

Also note that when you deploy your app to App Engine, only the source files are uploaded, and your app is compiled in the cloud. So you can't even "trick" it by compiling it locally and somehow "exclude" source files and upload only the binaries (binaries are not even uploaded).

You can't do anything else but wait for Go 1.7.1 (or a newer version) to make it to the SDK. Note that the Go version bundled in the SDK usually lags a few versions behind, because for it to become the "live" version, it usually needs modifications / altering for the sandboxed environment of App Engine (certain restrictions must be applied / implemented), and it needs further / additional testing / strengthening regarding security.

Answer 2

At this point you should be able to upgrade - App Engine has supported Go 1.8 since 2017 and recently announced early support for 1.9.

In general, though, you're pretty much stuck with the versions supported in production - there's no way to link in your own version of Go to the SDK, and I'd argue that it would be extremely ill-advised to do so even if you could.