The previous implementation would attempt to fetch groups using the end-user's Google auth token. This only worked for admin accounts, or users with 'delegated' access to the `admin.directory.group.readonly` API.
This commit changes the approach to use a single 'service account' for fetching the groups. This removes the need to add permissions to all regular user accounts. I'll be updating the [meta docs](https://meta.discourse.org/t/226850) with instructions on setting up the service account.
This is technically a breaking change in behavior, but the existing implementation was marked experimental, and is currently unusable in production google workspace environments.
This commit introduces a new site setting "google_oauth2_hd_groups". If enabled, group information will be fetched from Google during authentication, and stored in the Discourse database. These 'associated groups' can be connected to a Discourse group via the "Membership" tab of the group preferences UI.
The majority of the implementation is generic, so we will be able to add support to more authentication methods in the near future.
https://meta.discourse.org/t/managing-group-membership-via-authentication/175950
All the data we need for the `info` and `credentials` auth hash
are obtained via the user info API, not the JWT. Using and verifying
the JWT can fail due to clock skew, so let's skip it completely.
PR opened to fix the upstream issue at https://github.com/zquestz/omniauth-google-oauth2/pull/392
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
This fix ensures that users that are signing up via google oauth are
automatically added to any groups.
A similar fix will probably need to be added to other oauth providers.
