Moodle Oauth auto redirect
Moodle has great support for all SSO technology and Oauth in particular but within core there is no way to redirect your users directly into the Oauth workflow without them seeing the login screen.
This plugin silently redirects users from the login screen to the highest priority Oauth service that is enabled for logins.
To enable it just install the plugin (copy to the local directory) and set the "Alternate login URL" to "/local/oauthalternateloginurl/index.php"
If you wish to login without Oauth at any point just go to "/local/oauthalternateloginurl/index.php?skipoauth=true"