Google oauth2在每次登录时显示批准提示

Question

The problem is oauth2 login not works properly using https://github.com/golang/oauth2/ library.

Github works great and not shows approval prompt after once I've approved. But Google oauth2 shows approval prompt on every login.

Below url is golang oauth2 generated auth URL. And I didn't find the problem with it.

https://accounts.google.com/o/oauth2/auth?client_id=my_client_id&redirect_uri=redirect_url&response_type=code&scope=email+profile+https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fplus.login+https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fplus.profile.emails.read&state=state

The document(https://developers.google.com/youtube/v3/guides/authentication) said default approval_prompt value is auto.

I've approved the API Testing app properly. And confirmed it from permissions page(https://security.google.com/settings/security/permissions)

And then, https://accounts.google.com/o/oauth2/auth shows approval prompt again. I've double checked approval_prompt is not 'force'.

Answer 1

You can cache the token in a file and check on the start of your application, whether the token is still valid or not. You only need to show the approval prompt if the token is outdated.

This is the how I did it. The relevant code can be found here.