github-webhook

Generic webhook for GitHub's notifications.

The purpose of this software is to listen on a TCP port and wait for a push event via GitHub's Webhooks.

Configuration

A shared secret key must be exported as SECRET_KEY and it needs to match the key set in the GitHub configuration for the webhook. If the secret does not match the request is ignored and a 401 Unauthorized response is sent back.

The listening port must be exported as PORT.

If the secret matches the JSON object is printed to stdout and can be piped through jq and/or trigger a build process.

#!/bin/bash

SECRET_KEY=... ./github-webhook | while read json rest; do
  make
done

Caveats

When using daemontools to manage the process a simple unix pipe like the one above will leave the github-webhook hanging when trying to bring the process down.

A simple solution is to use socat to pipe github-webhook's stdout to a shell script.

#!/bin/sh

exec 2>&1
exec socat -u EXEC:'envdir env setuidgid nobody ./github-webhook' EXEC:'envdir env setuidgid nobody ./build.sh'

With build.sh:

#!/bin/bash

while read json; do
  reponame=$(echo $json | jq --raw-output '.repository.name')
  echo $reponame
  # ...
done