Setup GitHub Developer Portal
- Create a GitHub Developer account.
- Follow the documentation for creating an OAuth App in GitHub.
- Obtain a Client ID and Client Secret from GitHub OAuth. Be sure to set the redirect URL to your application handling the Nile Auth requests.
Github dashboard example

Save Client ID and Client Secret in Nile
Save them to your database at 
console.thenile.dev under GitHub in Tenants & Users -> Configuration\