Hi , odoo community and SME Malaysia and Singapore user base , have you been like me , trying to look for help in how to setup using the facebook login,
here you go , a complete guide for you  ,

Applicable version : V10 and above , V9 may work …

What you need to is the following steps … ,
*** First activate your Developer mode then you follow the steps ,
1. configure to allow user to sign up using Oauth 
    then in it , you make sure you fill in the correct value …
2. configure the Facebook app  , now go to your facebook , developer account ,
    https://developers.facebook.com , if you do not have , just apply one
    pretty straight forward , in it , create an App , 
then you have click on the Facebook Login  and select the  
    Redirect URI ,
    http:///auth_oauth/signin
3. Get the FB app-id and set to your odoo , facebook , client-id , as follow ,
same image as above then go back to your Odoo and key in the client id value here to remind you the app-id is your client id  …
4. should be good to go ,
    when you click sign in Facebook … 
    if your browser already has the facebook session ( you already login )
    then you should be able to see this …
   

so that will simplify your client to login into your great odoo powered sited , should you have any further requirements , such as support assistance or customization requirements and implementation consultation services , for handling your Malaysia and Singapore SME business requirement , do feel free to let us know , thanks, happy odooing  !
Cheers.