webhook-api/event.php

<?php

function httpCode($code) {
    http_response_code($code);
    headers_sent();
}

function response(array $content, $code = 200) {
    header('Content-type: application/json');
    httpCode($code);
    echo json_encode($content);
    exit;
}

function badSecret() {
    response(
        [
            'error' => 'Invalid secret',
        ],
        403
    );
}

function badRequest(array $content = []) {
    response($content, 404);
}

function requiredBagVar($bag, $index) {
    if (!array_key_exists($index, $bag)) {
        badRequest([
            'error' => 'Bad request',
            'missing_param' => [$index, $bag],
        ]);       
    }
}

function isValidSecret($secret, $accounts) {
    return in_array(
        $secret,
        $accounts
    );
}

requiredBagVar($_POST, 'payload');
$payload = json_decode($_POST['payload'], true);

requiredBagVar($payload, 'secret');
$accounts = require 'accounts.php';
if (!isValidSecret($payload['secret'], $accounts)) {
    badSecret();
}

$repository = preg_replace('/-project$/', '', $payload['repository']['name']);
$repository = str_replace(['/', '.'], '', $repository);

$command = 'sudo -u git $HOME/bin/webhook-project '.escapeshellarg($repository);
$execute = shell_exec($command);

response([
    'action' => 'Gitnet project push event',
    'output' => $execute,
]);