Enabling Oauth Login
Go to the Github Page in settings > OAuth Apps > New OAuth App’. The values for application name, homepage URL, or application description don’t matter. They can be customized however desired.
However, the authorization callback URL takes a specific value. It must be https://jenkins.example.com/securityRealm/finishLogin where jenkins.example.com is the location of the Jenkins server.
The important part of the callback URL is /securityRealm/finishLogin Finish by clicking Register application and you are done.
Webhook
To let Jenkins know of a new pull requets or commit you need to setup a webhook. In your Organization go to Settings > Webhooks > Add webhook. Add a webhook with the the Payload URL of your Jenkins Instance and leave settings as they are.
Branch Protection in a repository
Go to the main page of the repository > Settings > Branches > Add Rule. Apply the following.
- Apply rule to: master
- Require pull request reviews before merging
- Dismiss stale pull request approvals when new commits are pushed
- Include administrators