sample config about cakephp deployment using altax. (But I use it in real)

config.php

<?php
// Altax - http://kohkimakimoto.github.io/altax/

// Autoloading for plugin command classes.
if (is_file(__DIR__ . '/vendor/autoload.php')) require_once __DIR__ . '/vendor/autoload.php';

// ***************************************************************
// Server definition. - change here.
// ***************************************************************
Server::nodesFromSSHConfigHosts();
CONST PRODUCTION_SERVER_SSH_STRING = "name_of_ssh_config";

CONST BASE_PATH         = "/var/www/html";
$env['release']         = BASE_PATH."/releases";
$env['publish']         = BASE_PATH."/current";
$env['logs']            = BASE_PATH."/cake_logs";

$env['repository']      = "git@github.com:user_name/repository_name.git";
$env['prod_configs']    = array('database.php', 'core.php');
$env['locale']          = 'Asia/Tokyo';

// ***************************************************************
// Task definition.
// ***************************************************************
Task::register('deploy', function($task) use ($env){

    $task->exec(function($process) use ($env){
        date_default_timezone_set($env['locale']);
        $now = date('Y_m_d_His');
        $env['release'] = "{$env['release']}/{$now}";

        $process->run("git clone {$env['repository']} {$env['release']}");
        generate_sybolic_links($process, $env);
        clear_cake_caches($process, $env);
        switch_to_production_config($process, $env);
        switch_to_production_environment($process, $env);

        echo "Finish deploying.\n";
    }, array(PRODUCTION_SERVER_SSH_STRING));
})->description("Deploy master repogitory.");

function generate_sybolic_links($process, $env){
    $process->run( array(
        "cd {$env['release']}/app/tmp/",
        "rm -rf logs",
        "ln -s {$env['logs']}/logs logs"
        )
    );
    return;
}

function clear_cake_caches($process, $env){
    $process->run( array(
        "chmod -R 0777 {$env['release']}/app/tmp",
        "rm -rf {$env['release']}/app/tmp/cache/models/myapp_*",
        "rm -rf {$env['release']}/app/tmp/cache/persistent/myapp_*",
        "rm -rf {$env['release']}/app/tmp/cache/views/myapp_*",
        )
    );
    return;
}

function switch_to_production_config($process, $env){
    foreach ($env['prod_configs'] as $config) {
        $process->run( array(
            "cd {$env['release']}/app/Config",
            "rm -rf {$config}",
            "ln -s prod/{$config} {$config}"
            )
        );
    }
    return;
}

function switch_to_production_environment($process, $env){
    $process->run("rm -f {$env['publish']}; ln -s {$env['release']} {$env['publish']}");
    return;
}


Task::register('rollback', function($task) use ($env){
    $task->exec(function($process) use ($env){

        // the latest version, which you want to rollback
        $latest = get_latest($env);
        echo 'latest version: ' . $latest . "\n";

        // the previous version, which you want to activate
        $prev = get_prev($env, $latest);
        if (empty($prev)) {
            echo "There's no previous version. finished.\n";
            exit;
        }
        echo 'previous version: ' . $prev . "\n";

        // switch to previous version.
        date_default_timezone_set($env['locale']);
        $env_lastest = "{$env['release']}/{$latest}";
        $env['release'] = "{$env['release']}/{$prev}";

        generate_sybolic_links($process, $env);
        clear_cake_caches($process, $env);
        switch_to_production_config($process, $env);
        switch_to_production_environment($process, $env);

        // delete the latest version. -- it has troubles.
        $process->run("rm -rf {$env_lastest}");

        echo "Finisih rollbacking.\n";
    }, array(PRODUCTION_SERVER_SSH_STRING));
})->description("Rollback to previous version.");

function get_latest($env){
    $str = $process->run("readlink {$env['publish']}");
    $str = str_replace("{$env['release']}/", '', $str);
    $str = str_replace("\n", '', $str);
    return $str;
}

function get_prev($env, $latest){
    $releases = $process->run("ls -t {$env['release']}");
    $releases = explode("\n", $releases);

    $found = false;
    $prev = null;

    foreach ($releases as $release) {
        $release = trim($release);
        if ($found) {
            $prev = $release;
            break;
        }
        if ($release == $latest) $found = true;
    }

    return $prev;
}

Task::register('hist', function($task) use ($env){
    $task->exec(function($process) use ($env){

        echo "The List of deployed folders.\n";
        $releases = $process->run("ls -t {$env['release']}");

    }, array(PRODUCTION_SERVER_SSH_STRING));
})->description("Show the folder names which in release folder.");

Task::register('clean', function($task) use ($env){
    $task->exec(function($process) use ($env){

        $releases = $process->run("ls -t {$env['release']}");
        $releases = rtrim($releases, "\n");
        $releases = explode("\n", $releases);
        foreach ($releases as $key => $release) {
            if ($key > 4) {
                $release = trim($release);
                $process->run("rm -rf {$env['release']}/{$release}");
            }
        }

    }, array(PRODUCTION_SERVER_SSH_STRING));
})->description("Clean release directory without 5 histories.");

Please tell me bugs, miss-spellings, your opinion here.

32: $process->run("git clone {$env['repository']} {$env['release']}");
↓
$process->run("git clone --depth 1 {$env['repository']} {$env['release']}");