To make possible to authenticate via Google you must first to register application in Google
* Go to the [registration](https://code.google.com/apis/console) link.
* Press "API Access" in left menu bar.
* Click the button "Create an OAuth 2.0 client ID".
* When registering specify application name, for example, Redmine Oauth Google.
* In section "Your site or hostname" choose mode http, in the text input box enter your domain, for example, yourdomain.com.
* Press the button "Create client ID".
The registrations is complete.
### Configuration
* Login as administrator. In top menu select "Administration". Choose menu item Plugins. In plugins list choose "Redmine Omniauth Google plugin". Press "Configure".
* Fill Сlient ID & Client Secret by corresponding values, obtained by Google.
* Put the check "Oauth authentification", to make it possible to login through Google. Click Apply. Users can now to use apportunity to login via Google.
To limit login through Google for other domains you have to fill allowed domains in the text box field the "Allowed domains". Domains must be separated by newlines. For example:
onedomain.com
otherdomain.com
### Work process
User goes to the login page(sign in). User clicks the button with Google image. The plugin redirects him to Google. User enters his the еmail & password from Google. Google redirect user back to plugins controller. Then the following cases:
1. If auto registration is enabled, user is redirected to 'my/page'
