Strategy to authenticate with Google via OAuth2 in OmniAuth.
Get your API key at: https://code.google.com/apis/console/
For more details, read the Google docs: https://developers.google.com/accounts/docs/OAuth2
Add to your Gemfile
:
gem "omniauth-google-oauth2"
Then bundle install
.
Here's an example, adding the middleware to a Rails app in config/initializers/omniauth.rb
:
Rails.application.config.middleware.use OmniAuth::Builder do
provider :google_oauth2, ENV["GOOGLE_KEY"], ENV["GOOGLE_SECRET"]
end
You can now access the OmniAuth Google OAuth2 URL: /auth/google_oauth2
You can configure several options, which you pass in to the provider
method via a hash:
scope
: A comma-separated list, without spaces, of permissions you want to request from the user. See the Google OAuth 2.0 Playground for a full list of available permissions. Caveats:- The
userinfo.email
anduserinfo.profile
scopes are used by default. By defining your ownscope
, you override these defaults. If you need these scopes, don't forget to add them yourself! - Scopes starting with
https://www.googleapis.com/auth/
do not need that prefix specified. So while you should use the smaller scopebooks
since that permission starts with the mentioned prefix, you should use the full scope URLhttps://docs.google.com/feeds/
to access a user's docs, for example.
- The
approval_prompt
: Determines whether the user is always re-prompted for consent. It's set toforce
by default so a user sees a consent page even if he has previously allowed access a given set of scopes. Set this value toauto
so that the user only sees the consent page the first time he authorizes a given set of scopes.access_type
: Defaults tooffline
, so a refresh token is sent to be used when the user is not present at the browser. Can be set toonline
.
Here's an example of a possible configuration where the user is asked for extra permissions and is only prompted once for such permissions:
Rails.application.config.middleware.use OmniAuth::Builder do
provider :facebook, ENV["GOOGLE_KEY"], ENV["GOOGLE_SECRET"],
{
:scope => "userinfo.email,userinfo.profile,plus.me,http://gdata.youtube.com",
:approval_prompt => "auto"
}
end
Here's an example of an authentication hash available in the callback by accessing request.env["omniauth.auth"]
:
{
:provider => "google_oauth2",
:uid => "123456789",
:info => {
:name => "John Doe",
:email => "john@company_name.com",
:first_name => "John",
:last_name => "Doe",
:image => "https://lh3.googleusercontent.com/url/photo.jpg"
},
:credentials => {
:token => "token",
:refresh_token => "another_token",
:expires_at => 1354920555,
:expires => true
},
:extra => {
:raw_info => {
:id => "123456789",
:email => "user@domain.example.com",
:verified_email => true,
:name => "John Doe",
:given_name => "John",
:family_name => "Doe",
:link => "https://plus.google.com/123456789",
:picture => "https://lh3.googleusercontent.com/url/photo.jpg",
:gender => "male",
:birthday => "0000-06-25",
:locale => "en",
:hd => "company_name.com"
}
}
}
Copyright (c) 2012 by Josh Ellithorpe
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