Integration with Github Webhooks
Many CTF organizers will want to store their problems in a Github repository to make it easier to collaborate on problem writing. And since OpenCTF is run over Docker containers, adding problems to the platform can be a pain. A webhook is an endpoint that will cause the platform to automatically pull from a certain repository and add the problems in that repository to the database. This webhook can be triggered whenever someone pushes to the repository.
To enable this feature, make sure you are logged in with a user with administrative privileges, and head over to CTF Settings under the Admin dropdown in the navigation bar. Under the various panels, you will see one panel labeled Github Webhook. It will look something like this.
Come up with a secret that you will use to verify Github's payloads. Type this secret into the box, hit Save Settings. By adding a secret, you have enabled listening for webhooks on your platform. Now, you must create the webhook on Github. In your Github repository's settings, go to the tab on the left labeled Webhooks & services. Click Add webhook. You may arrive at a page that looks like this:
- For Payload URL, put
http://<your_domain>/api/admin/webhook, obviously replacing<your_domain>with your actual domain. - Leave Content type as
application/json. - Type in the secret that you created earlier for Secret.
- Ideally, you should leave triggers as just
pushevents, but it's up to you to change that value as you see fit. - Obviously, you'd want your webhook to be Active.
With this, your platform and Github know about each others' existence. But we're not done. Most likely, the Github repository that you use for storing your problems will be private so random stalkers can't access your competition problems before the competition begins. Therefore, the platform will need authentication to be able to pull from your repository.
Like you (hopefully), the platform is able to authenticate to Github through SSH keys. So you need to add the platform's public key to your repository. It's important to note that you are adding it to the repository only, and not your account. First, locate the public key in the CTF Settings screen from earlier where you created the secret. You should now see the platform's public key displayed. Then, go to your Github repository's settings page again, and this time, go to the Deploy keys tab instead. Upon clicking Add deploy key, you will be presented to a screen similar to this:
For Title, you may use whatever you'd like. For Key, paste the public key you found on the CTF Settings page. Leave the Allow write access box unchecked; the platform won't be needing to write to your repository.
If you followed all the steps correctly, your platform should be ready to listen for webhooks! Read on to find out how to format your repository.
// TODO Finish writing.