No need to post a full guide as @yariplus had the correct answer all the time. I just did not understand it at first.
Login into nodebb automatically from my web app
I have to implement a web app. This web app will have a login for the user. Internally it will have an own user account database and an access rights management.
In addition I have to integrate a community forum like nodebb. It is the goal to switch to the forum with automatic login (single sign in SSO). I think nodebb has it's own user account database.
How to synchronize both user account databases and realize SSO?
@pitaj https://github.com/julianlam/nodebb-plugin-session-sharing explains to to use this plugin and sesssion sharing to automatically login. SSO and OAuth2 is not needed.
There is also a forum entry https://community.nodebb.org/topic/11372/sso-single-sign-on-opportunities which suggest to use SSO and OAuth2 in order to share sessions.
"... The recommended method of sharing sessions between two separate and distinct applications is through OAuth2. ..."
I am a little bit confused. Who is wrong?
Do I misunderstand something?
@grabmaier That question specifically asks about SSO. Session sharing is different in that it allows your user to skip the login altogether IIRC which is what you want.