How to automatically deploy from GitHub - https://keithgreer.dev/git-automatically-deploy-website-github

deploy.php

<?php

// Forked from https://gist.github.com/1809044
// Available from https://keithgreer.uk/git-automatically-deploy-website-github

// Check if client is allowed
$allowed_ips = array(
    '207.97.227.', '50.57.128.', '108.171.174.', '50.57.231.', '204.232.175.', '192.30.252.', // GitHub
    '123.123.123.123' // Your own IP address
);

$allowed = false;

$headers = apache_request_headers();

if (@$headers["X-Forwarded-For"]):
    $ips = explode(",",$headers["X-Forwarded-For"]);
    $ip  = $ips[0];
else:
    $ip = $_SERVER['REMOTE_ADDR'];
endif;

foreach ($allowed_ips as $allow):
    if (stripos($ip, $allow) !== false):
        $allowed = true;
        break;
    endif;
endforeach;

// If not allowed
if (!$allowed):
    header('HTTP/1.1 403 Forbidden');
    exit;
endif;

flush();

// If they are allowed
$commands = array(
    'echo $PWD',
    'whoami',
    'git pull',
    'git status',
    'git submodule sync',
    'git submodule update',
    'git submodule status',
    'test -e /usr/share/update-notifier/notify-reboot-required && echo "system restart required"',
);

$output = "\n";

// Add new deploy to log file
$log = "####### ".date('Y-m-d H:i:s'). " #######\n";

// Loop through commands
foreach($commands AS $command):
    $tmp = shell_exec("$command 2>&1");
    $output .= "\$ {$command}\n";
    $log  .= "\$ $command\n".trim($tmp)."\n";
endforeach;

$log .= "\n";

// Save output to log
file_put_contents ('deploy.log',$log,FILE_APPEND);