This is a literal, not so idiomatic ruby port of Michael Jett's excellent OpenID Connect library for PHP.
gem install openid_connect_client
It's done in two steps: first, in your login controller you'll request authorization and redirect the user to the OpenID Connect provider. If your app gets authorized, then the provider will redirect the user back to your callback url where you'll be able to ask the provider for the user data.
See example.rb
# 1. Client setup
oidc = OpenIDConnectClient::Client.new('https://provider.com/openid', 'CLIENT_ID', 'SECRET')
oidc.redirect_url = "http://yourweb.com/callback"
oidc.scopes = "openid email profile address"
# 2. Request authorization
oidc.authorize()
# 3. Save state in session
session[:state] = oidc.state
# 4. Redirect user to OpenID Connect provider
redirect_to(oidc.auth_endpoint)# 1. Get client
oidc = OpenIDConnectClient::Client.new('https://provider.com/openid', 'CLIENT_ID', 'SECRET')
# 2. Restore state
oidc.state = session[:state]
# 3. Pass the authorization parameters sent by the provider
oidc.params = request.parameters
# 4. Authenticate your app against the provider
oidc.authenticate()
# 5. Fetch the user's details
given_name = oidc.get('given_name')
email = oidc.get('email')
address = oidc.get('address')