A Github webhook implementation to address Drone IO's missing "auto-cancelation of previous builds" feature.

• David Almendarez (@david)

On push and on pull_request events are sent to the flask web-hook app and is authenticated using a SECRET env var named WEBHOOK_VERIFY_TOKEN. This token is then compared with the SECRET setup on your Github web-hook settings page for your repository as shown below:

The flask app then compares the sha1 after (hash) sent by either of those aforementioned events with the latest (last) Drone IO builds hash, if the hash do not match, that Drone build is then canceled (or stopped) via the Drone API. The Drone API is authenticated via a few env vars, listed below, so please assign these env vars on the machine running your web-hook.

• WEBHOOK_VERIFY_TOKEN: A string, should be kept a secret; used to authenticate your app with Github's web-hook mechanism. This needs to match the secret value entered on your repo's webhook settings page.
• DRONE_SERVER: should be set as https://drone.britecorepro.com
• DRONE_TOKEN: your personal access token displayed on your profile page on our drone server (listed above).
• DRONE_REPO_OWNER_USERNAME: your github username, i.e.: SirFroweey is mine. Should be set to IntuitiveWebSolutions if we decide to host this app on our DevOps infrastructure.
• DRONE_REPO_NAME: your repository name, i.e.: 'BriteCore' or in this case DroneAutoCancel.
• ONLY_PROCESS_PR_EVENTS: Boolean, should our hook only process pull_request event types? Defaults to False.

• Setup your local machines environmental variables as shown above.
• Clone this repository onto your machine.
• cd into your repository directory.
• Run pip install -r requirements.txt or even better, setup a virtualenv and activate it then install the requirements.
• Download ngrok and move it into your Applications/ folder.
• Create a symlink, as shown here:

# cd into your local bin directory
cd /usr/local/bin

# create symlink
ln -s /Applications/ngrok ngrok

• Run python hook.py on your terminal of choice
• Execute ngrok http 5000
• Setup your repo's Github webhook as shown below and point it to your ngrok https URL that we generated earlier (via the ngrok http 5000 command):

• The Github event event should report back as successful with a green 200 status code, as shown below:

• Pushing to your repository where you setup your web-hook (presumably your BriteCore fork), should report back with a successful 200 response as shown below:

Experimental for now, ask @david for access to private repo.

1. Install Docker
2. docker login
3. Run docker-compose up
4. Navigate to 127.0.0.1:5000/webhook on your web browser and ensure you get a 405 page, this signals a successful startup.
5. Download ngrok and move it into your Applications/ folder.
6. Create a symlink, as shown here:

# cd into your local bin directory
cd /usr/local/bin

# create symlink
ln -s /Applications/ngrok ngrok

7. Execute ngrok http 5000
8. Setup your repo's Github webhook as shown below and point it to your ngrok https URL that we generated earlier (via the ngrok http 5000 command):

• The Github event event should report back as successful with a green 200 status code, as shown below:

9. Pushing to your repository where you setup your web-hook (presumably your BriteCore fork), should report back with a successful 200 response as shown below:

• It may be best to uncheck the push event from the Github web-hook settings page to prevent being spamming by 400 requests due to the push event being filtered out when setting the ONLY_PROCESS_PR_EVENTS environment variable to True.