How to read cookies in rails app set by some different application

I need to read cookies set by some different application into my rails application. both the application is running under common SSO (authentication) and when the user successfully authenticated he first redirected to the first application (Node/Express app) which write some data into browser cookies and then when the user clicks on some button which loads my rails application. it will create a rails session. I need to set some variables reading from the cookie set by node/express application.