I have SiteA storing user information(name, office, department etc.). The back end has exposed REST WS that give the information to the front end. The site uses Google OAuth2 authentication - Users log in via Google account. With OAuth2 we let google handle the login(without asking for username and password). Google generates an authorization code that is used with the client_id and client_secret to generate an token for the user.
I have SiteB. I am creating a job that is going to be executed once a day. I need it to login programmatically to SiteA so I can get a security token that I can use in requests to the REST WS API provided by SiteA and fetch the needed information.
I was unable to find a similar question online. Everything usually ends up to the user opening a browser and navigating to an approaval URL.
Something similar is Google Drive API - OAuth2.0: How to Automate Authentication Process? Doubts and Questions, but it is about connecting to Google Drive without login.
I am starting to doubt that it is possible. Have anyone figured out how to implement this way of communication between systems?
The only option that I could thing of is connecting to SiteA DB and extracting records manually, but that would duplicate the login in SiteA and SiteB.