How to do AppEngine Go 1.16 local development?

Question

AppEngine supports Go 1.16 for a year now. But dev_appengine.py still doesn't:

RuntimeError: Unknown runtime 'go116'; supported runtimes are 'custom', 'go', 'go111', 'go112', 'go113', 'go114', 'go115', 'java', 'java7', 'java8', 'php55', 'php72', 'php81', 'python', 'python-compat', 'python27', 'python310', 'python37', 'python38', 'python39'.

The official documentation is unhelpful.

How can I do local Go 1.16 development of my AppEngine app?

Answer 1

I assume you meant dev_appserver.py and not dev_appengine.py. If so, then

1. It looks like you're using GAE Standard env in which case, gcloud CLI version 409.0.0 (which seems to be the latest, at least for Mac) doesn't support go 1.1.6. The go runtimes supported in it are

 go, go111, go112, go113, go114, go115

You can find the list of supported runtimes in the file 

{{path to gcloud sdk_installation}}/platform/google_appengine/google/appengine/tools/devappserver2/runtime_factories.py

2. If you switch to GAE Flex, I believe you'll be able to use go 1.1.6 since you'll then be using a custom runtime

3. You can also just run your App as you would a standard go App e.g using command go run <go_package>