Вот мой код.
elsif auth.provider == 'linkedin'
user.email = auth.info.email
user.password = Devise.friendly_token[0,20]
user.first_name = auth.info.name
user.last_name = auth.info.name
user.uid = auth.uid
user.provider = auth.provider
user.oauth_token = auth.credentials.token
user.save!