Hedge

Percy/GitHub integration to update GitHub pull request statuses without granting Percy full read/write access to your repositories.

This runs as a server that listens for GitHub pull request and push webhooks, polls the Percy API for build status based on the received SHAs, and updates the GitHub API with corresponding status updates.

You must have a read API key from Percy for the poller to work. This is not available in the UI, so contact their support for such a key.

@dradford made this sick diagram of how it works.

      GitHub PR / push ----> Hedge ---> Percy
                          
                         Hedge ---> Percy  
                              <---              
                             |             
     GitHub SHA pending  <----             

  ^---------------------------------------->
  |                                        |
  |                      Hedge ---> Percy  |
  |                            <---        |
  |                               |        |
  |   GitHub API status check <----        |
  |                                        |
  <----------------------------------------v
                      
                         Hedge ---> Percy
                               <---        
                              |            
 GitHub API SHA success  <----             

Setup

Hedge has no external service dependencies, just run the server with mix run --no-halt. (This means there is no persistence, so you will probably need to override occasional builds if you let the server go down.)

Once it's running and available on the internet, set up a GitHub webhook pointing to the /hooks endpoint of your server, and configure it to send only pull_request events.