deploy.php

<?php

error_reporting(E_ALL);
ini_set('display_errors', true);

define('SSH_HOST', '');
define('SSH_PORT', 666);
define('SSH_USER', '');
define('SSH_PASS', '');
define('REMOTE_PATH', '/var/www/');
define('REPOSITORY', 'git@gitar.io:gg/foo.git');


$ssh_client = new SSH2Client(SSH_HOST, SSH_PORT);
$ssh_client->auth(SSH_USER, SSH_PASS);
$ssh_client->connect();

if (!empty($_SERVER['argv'][1]) && $_SERVER['argv'][1] === 'init') {
    echo $ssh_client->exec(sprintf('git clone %s %s', REPOSITORY, REMOTE_PATH));
} else {
    echo $ssh_client->exec(sprintf('cd %s && git pull 2>&1', REMOTE_PATH));
}

$ssh_client->close();
unset($ssh_client);


class SSH2Client
{
    protected $connection;

    protected $host;

    protected $port;

    protected $user;

    protected $password;

    public function __construct($host, $port = 22)
    {
        $this->host = $host;
        $this->port = (int) $port;
    }

    public function __destruct()
    {
        if (is_resource($this->connection)) {
            $this->close();
        }
    }

    public function connect()
    {
        if (!$this->connection = ssh2_connect($this->host, $this->port)) {
            throw new Exception(sprintf('Cannot connect to server: %s', $this->host));
        }

        if (!ssh2_auth_password($this->connection, $this->user, $this->password)) {
            throw new Exception('Authentication Failed');
        }
    }

    public function close()
    {
        $this->exec('echo "EXITING" && exit;');
        $this->connection = null;
    }

    public function auth($user, $password = null)
    {
        $this->user = $user;
        $this->password = $password;
        return $this;
    }

    public function exec($cmd, $pty = null, array $env = array(), $width = 80, $height = 25, $width_height_type = SSH2_TERM_UNIT_CHARS)
    {
        $stdout = ssh2_exec($this->connection, $cmd, $pty, $env, $width, $height, $width_height_type);
        $stderr = ssh2_fetch_stream($stdout, SSH2_STREAM_STDERR);
        stream_set_blocking($stderr, true);
        stream_set_blocking($stdout, true);
        $error = stream_get_contents($stderr);
        if ($error !== '') {
            throw new RuntimeException($error);
        }
        return stream_get_contents($stdout);
    }
}