Scaling Silex applications (part II). Using RouteCollection

In the post Scaling Silex applications I wanted to organize a one Silex application. In one comment Igor Wiedler recommended us to use RouteCollections instead of define the routes with a Symfony’s Dependency Injection Container. Because of that I started to hack a little bit about it and here I show you my outcomes:

I want to build an imaginary application with silex. This application has also one Api and one little blog. I want to organize those parts. Our index.php file

<?php
// www/index.php
require_once __DIR__ . '/../vendor/autoload.php';

use Symfony\Component\Config\FileLocator;
use Symfony\Component\Routing\Loader\YamlFileLoader;
use Symfony\Component\Routing\RouteCollection;
use Silex\Application;

$app = new Application();

$app['routes'] = $app->extend('routes', function (RouteCollection $routes, Application $app) {
    $loader     = new YamlFileLoader(new FileLocator(__DIR__ . '/../config'));
    $collection = $loader->load('routes.yml');
    $routes->addCollection($collection);

    return $routes;
});

$app->run();

Now our routes.yml file:

# config/routes.yml

home:
  path: /
  defaults: { _controller: 'Gonzalo123\AppController::homeAction' }

hello:
  path: /hello/{name}
  defaults: { _controller: 'Gonzalo123\AppController::helloAction' }

api:
  prefix: /api
  resource: api.yml

blog:
  prefix: /blog
  resource: blog.yml

As we can see we have separated the main routing file into different files: api.yml (for the Api) and blog.yml (for the blog)

# config/api.yml

api.list:
  path:     /list
  defaults: { _controller: 'Gonzalo123\ApiController::listAction' }
# blog.yml

blog.home:
  path:     /
  defaults: { _controller: 'Gonzalo123\BlogController::homeAction' }

And now we can create our controllers:

<?php
// lib/Gonzalo123/AppController.php

namespace Gonzalo123;

use Symfony\Component\HttpFoundation\Response;
use Silex\Application;

class AppController
{
    public function homeAction()
    {
        return new Response("AppController::homeAction");
    }

    public function helloAction(Application $app, $name)
    {
        return new Response("Hello" . $app->escape($name));
    }
}
<?php
// lib/Gonzalo123/ApiController.php

namespace Gonzalo123;

use Symfony\Component\HttpFoundation\Response;

class ApiController
{
    public function listAction()
    {
        return new Response("AppController::listAction");
    }
}
<?php
// lib/Gonzalo123/BlogController.php

namespace Gonzalo123;

use Symfony\Component\HttpFoundation\Response;

class BlogController
{
    public function homeAction()
    {
        return new Response("BlogController::homeAction");
    }
}

And that’s all. Here also the needed dependencies within our composer.json file

{
    "require":{
        "silex/silex":"1.0.*@dev",
        "symfony/yaml":"v2.2.0",
        "symfony/config":"v2.2.0"
    },
    "autoload":{
        "psr-0":{
            "":"lib/"
        }
    }
}

source code at github.

Scaling Silex applications

In my humble opinion Silex is great. It’s perfect to create prototypes, but when our application grows up it turns into a mess. That was what I thought until the last month, when I attended to a great talk about Silex with Javier Eguiluz. OK. Scaling Silex it’s not the same than with a Symfony application, but it’s possible.

It’s pretty straightforward to create a Silex application with composer:

{
    "require": {
        "silex/silex": "1.0.*"
    },
    "minimum-stability": "dev"
}

But there’s a better way. We can use the Fabien Potencier’s skeleton. With this skeleton we can organize our code better.

We also can use classes as controllers instead of using a closure with all the code. Igor Wiedler has a great post about this. You can read it here.

Today I’m playing with Silex and I want to show you something. Let’s start:

Probably you know that I’m a big fan of Symfony’s Dependency Injection Container (you can read about it here and here), but Silex uses Pimple. In fact the Silex application extends Pimple Class. My idea is the following one:

In the Igor’s post we can see how to use things like that:

$app->match('/video/{id}', 'Gonzalo123\ApiController::indexAction')->method('GET')->bind('video_info');

My idea is to store this information within a Service Container (we will use Symfony’s DIC). For example here we can see our routes.yml:

routes:
  video_info:
    pattern:  /video/{id}
    controller: Gonzalo123\ApiController::initAction
    requirements:
      _method:  GET

As we can see we need to implement one Extension for the alias “routes”. We only will implement the needed functions for YAML files in this example.

<?php

use Symfony\Component\DependencyInjection\Extension\ExtensionInterface;
use Symfony\Component\DependencyInjection\ContainerBuilder;

class SilexRouteExtension implements ExtensionInterface
{
    /**
     * Loads a specific configuration.
     *
     * @param array            $config    An array of configuration values
     * @param ContainerBuilder $container A ContainerBuilder instance
     *
     * @throws InvalidArgumentException When provided tag is not defined in this extension
     *
     * @api
     */
    public function load(array $config, ContainerBuilder $container)
    {

    }

    /**
     * Returns the namespace to be used for this extension (XML namespace).
     *
     * @return string The XML namespace
     *
     * @api
     */
    public function getNamespace()
    {

    }

    /**
     * Returns the base path for the XSD files.
     *
     * @return string The XSD base path
     *
     * @api
     */
    public function getXsdValidationBasePath()
    {

    }

    /**
     * Returns the recommended alias to use in XML.
     *
     * This alias is also the mandatory prefix to use when using YAML.
     *
     * @return string The alias
     *
     * @api
     */
    public function getAlias()
    {
        return "routes";

    }
}

And now we only need to prepare the DIC. According to Fabien’s recommendation in his Silex skeleton, we only need to change the src/controllers.php

<?php

use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\Config\FileLocator;
use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;

// Set up container
$container = new ContainerBuilder();
$container->registerExtension(new SilexRouteExtension);
$loader = new YamlFileLoader($container, new FileLocator(__DIR__ . '/../config/'));
// load configuration
$loader->load('routes.yml');
$app['container'] = $container;

$app->mount('/api', include 'controllers/myApp.php');

$container->compile();

$app->error(function (\Exception $e, $code) use ($app) {
    if ($app['debug']) {
        return;
    }

    $page = 404 == $code ? '404.html' : '500.html';

    return new Response($app['twig']->render($page, array('code' => $code)), $code);
});

and now we define the config/routes.yml

routes:
  video_info:
    pattern:  /video/{videoId}
    controller: Gonzalo123\ApiController::initAction
    requirements:
      _method:  GET

And finally the magic in our controllers/myApp.php:

<?php

$myApp = $app['controllers_factory'];

foreach ($container->getExtensionConfig('routes')[0] as $name => $route) {
    $controller = $myApp->match($route['pattern'], $route['controller']);
    $controller->method($route['requirements']['_method']);
    $controller->bind($name);
}
return $myApp;

The class for this example is: src/Gonzalo123/ApiController.php

<?php

namespace Gonzalo123;

use Silex\Application;
use Symfony\Component\HttpFoundation\Request;

use Symfony\Component\HttpFoundation\JsonResponse;

class ApiController
{
    public function initAction(Request $request, Application $app)
    {
        return new JsonResponse(array(1, 1, $request->get('id')));
    }
}

As you can see the idea is to use classes as controllers, define them within the service container and build the silex needed code iterating over the configuration. What do you think?

How to configure Symfony’s Service Container to use Twitter API

Keeping on with the series about Symfony’s Services container (another posts here and here), now we will use the service container to use Twitter API from a service.

To use Twitter API we need to handle http requests. I’ve written several post about http request with PHP (example1, example2), but today we will use one amazing library to build clients: Guzzle. Guzzle is amazing. We can easily build a Twitter client with it. There’s one example is its landing page:

<?php
$client = new Client('https://api.twitter.com/{version}', array('version' => '1.1'));
$oauth  = new OauthPlugin(array(
    'consumer_key'    => '***',
    'consumer_secret' => '***',
    'token'           => '***',
    'token_secret'    => '***'
));
$client->addSubscriber($oauth);

echo $client->get('/statuses/user_timeline.json')->send()->getBody();

If we are working within a Symfony2 application or a PHP application that uses the Symfony’s Dependency injection container component you can easily integrate this simple script in the service container. I will show you the way that I use to do it. Let’s start:

The idea is simple. First we include guzzle within our composer.json and execute composer update:

    "require": {
        "guzzle/guzzle":"dev-master"
    }

Then we will create two files, one to store our Twitter credentials and another one to configure the service container:

# twitter.conf.yml
parameters:
  twitter.baseurl: https://api.twitter.com/1.1

  twitter.config:
    consumer_key: ***
    consumer_secret: ***
    token: ***
    token_secret: ***
# twitter.yml
parameters:
  class.guzzle.response: Guzzle\Http\Message\Response
  class.guzzle.client: Guzzle\Http\Client
  class.guzzle.oauthplugin: Guzzle\Plugin\Oauth\OauthPlugin

services:
  guzzle.twitter.client:
    class: %class.guzzle.client%
    arguments: [%twitter.baseurl%]
    calls:
      - [addSubscriber, [@guzzle.twitter.oauthplugin]]

  guzzle.twitter.oauthplugin:
    class: %class.guzzle.oauthplugin%
    arguments: [%twitter.config%]

And finally we include those files in our services.yml:

# services.yml
imports:
- { resource: twitter.conf.yml }
- { resource: twitter.yml }

And that’s all. Now we can use the service without problems:

<?php

namespace Gonzalo123\AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;

class DefaultController extends Controller
{
    public function indexAction($name)
    {
        $twitterClient = $this->container->get('guzzle.twitter.client');
        $status = $twitterClient->get('statuses/user_timeline.json')
             ->send()->getBody();

        return $this->render('AppBundle:Default:index.html.twig', array(
            'status' => $status
        ));
    }
}

Handling several DBAL Database connections in Symfony2 through the Dependency Injection Container with PHP

(This post is the second part of my previous post: Handling several PDO Database connections in Symfony2 through the Dependency Injection Container with PHP. You can read it here)

OK. We can handle PDOs connections inside a Symfony2 application, but what happens if we prefer DBAL. As we know DBAL is built over PDO and adds a set of “extra” features to our database connection. It’s something like PDO with steroids.

If we read the documentation, we will see how to use DBAL:

<?php
$config = new \Doctrine\DBAL\Configuration();
//..
$connectionParams = array(
    'dbname' => 'mydb',
    'user' => 'user',
    'password' => 'secret',
    'host' => 'localhost',
    'driver' => 'pdo_mysql',
);
$conn = DriverManager::getConnection($connectionParams, $config);

As we can see to obtain a DBAL connection we use a factory method in DriverManager class. We can easily implements it in our service container:

# databases.yml
parameters:
  doctrine.dbal.configuration: Doctrine\DBAL\Configuration
  doctrine.dbal.drivermanager: Doctrine\DBAL\DriverManager

  database.db1:
    driver: pdo_sqlite
    memory: true
  database.db2:
    driver: pdo_pgsql
    dbname: testdb
    user: username
    password: password
    host: 127.0.0.1

services:
  dbal_configuartion:
    class: %doctrine.dbal.configuration%
  db1:
    factory_class: %doctrine.dbal.drivermanager%
    factory_method: getConnection
    arguments: [%database.db1%]
  db2:
      factory_class: %doctrine.dbal.drivermanager%
      factory_method: getConnection
      arguments: [%database.db2%]

But if we run again our example Symfony will throws us one error:

RuntimeException: Please add the class to service “db1” even if it is constructed by a factory since we might need to add method calls based on compile-time checks.

If we use this service container configuration outside Symfony2 application it works (remember we can use Symfony’s Dependency Injection Container outside Symfony application as a component. Example here). But if we want to use it with Symfony2 we need to set the “class”, even here when we only need the static constructor, so we change it to:

# databases.yml
parameters:
  doctrine.dbal.configuration: Doctrine\DBAL\Configuration
  doctrine.dbal.drivermanager: Doctrine\DBAL\DriverManager

  database.db1:
    driver: pdo_sqlite
    memory: true
  database.db2:
    driver: pdo_pgsql
    dbname: testdb
    user: username
    password: password
    host: 127.0.0.1

services:
  dbal_configuartion:
    class: %doctrine.dbal.configuration%
  db1:
    class: %doctrine.dbal.drivermanager%
    factory_class: %doctrine.dbal.drivermanager%
    factory_method: getConnection
    arguments: [%database.db1%]
  db2:
    class: %doctrine.dbal.drivermanager%
    factory_class: %doctrine.dbal.drivermanager%
    factory_method: getConnection
    arguments: [%database.db2%]

And that’s all. We can use DBAL instead of PDO in our database connections.

UPDATE:

After publishing this post someone comment me Doctrine allows us to do it “out of the box” within Symfony with its DoctrineBundle:

https://github.com/doctrine/DoctrineBundle/blob/master/Resources/doc/configuration.rst#doctrine-dbal-configuration

Handling several PDO Database connections in Symfony2 through the Dependency Injection Container with PHP

I’m not a big fan of ORMs, especially in PHP world when all dies at the end of each request. Plain SQL is easy to understand and very powerful. Anyway in PHP we have Doctrine. Doctrine is a amazing project, probably (with permission of Symfony2) the most advanced PHP project, but I normally prefer to work with SQL instead of Doctrine.

Symfony framework is closely coupled to Doctrine and it’s very easy to use the ORM from our applications. But as I said before I prefer not to use it. By the other hand I have another problem. Due to my daily work I need to connect to different databases (not only one) in my applications. In Symfony2 we normally configure the default database in our parameters.yml file:

# parameters.yml
parameters:
    database_driver: pdo_pgsql
    database_host: localhost
    database_port: 5432
    database_name: symfony
    database_user: username
    database_password: password

Ok. If we want to use PDO objects with different databases, we can use something like that:

# parameters.yml
parameters:
  database.db1.dsn: sqlite::memory:
  database.db1.username: username
  database.db1.password: password

  database.db2.dsn: pgsql:host=127.0.0.1;port=5432;dbname=testdb
  database.db2.username: username
  database.db2.password: password

And now create the PDO objects within our code with new \PDO():

$dsn      = $this->container->getParameter('database.db1.dsn');
$username = $this->container->getParameter('database.db1.username');
$password = $this->container->getParameter('database.db1.password')

$pdo = new \PDO($dsn, $username, $password);

It works, but it’s awful. We store the database credentials in the service container but we aren’t using the service container properly. So we can do one small improvement. We will create a new configuration file called databases.yml and we will include this new file within the services.yml:

# services.yml
imports:
- { resource: databases.yml }

And create our databases.yml:

# databases.yml
parameters:
  db.class: Gonzalo123\AppBundle\Db\Db

  database.db1.dsn: sqlite::memory:
  database.db1.username: username
  database.db1.password: password

  database.db2.dsn: pgsql:host=127.0.0.1;port=5432;dbname=testdb
  database.db2.username: username
  database.db2.password: password

services:
  db1:
    class: %db.class%
    calls:
      - [setDsn, [%database.db1.dsn%]]
      - [setUsername, [%database.db1.username%]]
      - [setPassword, [%database.db1.password%]]
  db2:
    class: %db.class%
    calls:
      - [setDsn, [%database.db2.dsn%]]
      - [setUsername, [%database.db2.username%]]
      - [setPassword, [%database.db2.password%]]

As we can see we have created two new services in the dependency injection container called db1 (sqlite in memory) and db2 (one postgreSql database) that use the same class (in this case ‘Gonzalo123\AppBundle\Db\Db’). So we need to create our Db class:

<?php

namespace Gonzalo123\AppBundle\Db;

class Db
{
    private $dsn;
    private $username;
    private $password;

    public function setDsn($dsn)
    {
        $this->dsn = $dsn;
    }

    public function setPassword($password)
    {
        $this->password = $password;
    }

    public function setUsername($username)
    {
        $this->username = $username;
    }

    /** @return \PDO */
    public function getPDO()
    {
        $options = array(\PDO::ATTR_ERRMODE => \PDO::ERRMODE_EXCEPTION);
        return new \PDO($this->dsn, $this->username, $this->password, $options);
    }
}

And that’s all. Now we can get a new PDO object from our service container with:

$this->container->get('db1')->getPDO();

Better, isn’t it? But it’s still ugly. We need one extra class (Gonzalo123\AppBundle\Db\Db) and this class creates a new instance of PDO object (with getPDO()). Do we really need this class? the answer is no. We can change our service container to:

# databases.yml
parameters:
  pdo.class: PDO
  pdo.attr_errmode: 3
  pdo.erromode_exception: 2
  pdo.options:
    %pdo.attr_errmode%: %pdo.erromode_exception%

  database.db1.dsn: sqlite::memory:
  database.db1.username: username
  database.db1.password: password

  database.db2.dsn: pgsql:host=127.0.0.1;port=5432;dbname=testdb
  database.db2.username: username
  database.db2.password: password

services:
  db1:
    class: %pdo.class%
    arguments:
      - %database.db1.dsn%
      - %database.db1.username%
      - %database.db1.password%
      - %pdo.options%
  db2:
    class: %pdo.class%
    arguments:
      - %database.db2.dsn%
      - %database.db2.username%
      - %database.db2.password%
      - %pdo.options%

Now we don’t need getPDO() and we can get the PDO object directly from service container with:

$this->container->get('db1');

And we can use something like this within our controllers (or maybe better in models):

<?php

namespace Gonzalo123\AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;

class DefaultController extends Controller
{
    public function indexAction($name)
    {
        // this code should be out from controller, in a model object.
        // It is only an example
        $pdo = $this->container->get('db1');
        $pdo->exec("CREATE TABLE IF NOT EXISTS messages (id INTEGER PRIMARY KEY, title TEXT, message TEXT)");
        $pdo->exec("INSERT INTO messages(id, title, message) VALUES (1, 'title', 'message')");
        $data = $pdo->query("SELECT * FROM messages")->fetchAll();
        //

        return $this->render('AppBundle:Default:index.html.twig', array('usuario' => $data));
    }
}

Multiple inheritance with PHP and Traits

Multiple inheritance isn’t allowed in PHP. With Python we can do things like that:

class ClassName(Base1, Base2):
    ....

That’s no possible with PHP (in Java is not possible either), but today we can do something similar (is not the exactly the same) with Traits. Let me explain that: Instead of classes we can create Traits:

<?php
trait Base1
{
    public function hello1($name)
    {
        return "Hello1 {$name}";
    }
} 

trait Base2
{
    public function hello2($name)
    {
        return "Hello2 {$name}";
    }
} 

And now we can use those traits (instead of to extend multiple classes)

<?php
class ClassName
{
    use Base1, Base2;
} 

The main reason because multiple inheritance isn’t allowed in PHP, Java and another languages is is due to the collisions. If we extends from two classes with the same method, which is the good one?
Python solves this problem with a easy solution: The first one is the good one:

class Base1:
    def hello1(self, name):
        return "Hello1 " + name

class Base2:
    def hello1(self, name):
        return "Hello2 " + name

class ClassName(Base1, Base2):
    pass
c = ClassName()
print c.hello1("Gonzalo")

Will output “Hello1 Gonzalo” but if change the inheritance order to:

class ClassName(Base2, Base1):
    pass

The output will be “Hello2 Gonzalo”

Traits in PHP doesn’t solve the problem “out of the box”. If we use the following script:

<?php
trait Base1
{
    public function hello1($name)
    {
        return "Hello1 {$name}";
    }
}

trait Base2
{
    public function hello1($name)
    {
        return "Hello2 {$name}";
    }
}

class ClassName
{
    use Base1, Base2;
}

$class = new ClassName();
echo $class->hello1("Gonzalo");

Our script will throw a Fatal error:

PHP Fatal error: Trait method hello1 has not been applied, because there are collisions with other trait methods on ClassName on line 23

If we want to avoid collisions, we need to describe explicitly what function we will use. It’s not difficult:

<?php
trait Base1
{
    public function hello1($name)
    {
        return "Hello1 {$name}";
    }
}

trait Base2
{
    public function hello1($name)
    {
        return "Hello2 {$name}";
    }
}

class ClassName
{
    use Base1, Base2 {
        Base1::hello1 insteadof Base2;
    }
}

$class = new ClassName();
echo $class->hello1("Gonzalo");

Sending sockets from PostgreSQL triggers with Python

Picture this: We want to notify to one external service each time that one record is inserted in the database. We can find the place where the insert statement is done and create a TCP client there, but: What happens if the application that inserts the data within the database is a legacy application?, or maybe it is too hard to do?. If your database is PostgreSQL it’s pretty straightforward. With the “default” procedural language of PostgreSQL (pgplsql) we cannot do it, but PostgreSQL allows us to use more procedural languages than plpgsql, for example Python. With plpython we can use sockets in the same way than we use it within Python scripts. It’s very simple. Let me show you how to do it.

First we need to create one plpython with our TCP client

CREATE OR REPLACE FUNCTION dummy.sendsocket(msg character varying, host character varying, port integer)
  RETURNS integer AS
$BODY$
  import _socket
  try:
    s = _socket.socket(_socket.AF_INET, _socket.SOCK_STREAM)
    s.connect((host, port))
    s.sendall(msg)
    s.close()
    return 1
  except:
    return 0
$BODY$
  LANGUAGE plpython VOLATILE
  COST 100;
ALTER FUNCTION dummy.sendsocket(character varying, character varying, integer)
  OWNER TO username;

Now we create the trigger that use our socket client.

CREATE OR REPLACE FUNCTION dummy.myTriggerToSendSockets()
RETURNS trigger AS
$BODY$
   import json
   stmt = plpy.prepare("select dummy.sendSocket($1, $2, $3)", ["text", "text", "int"])
   rv = plpy.execute(stmt, [json.dumps(TD), "host", 26200])
$BODY$
LANGUAGE plpython VOLATILE
COST 100;

As you can see in my example we are sending all the record as a JSON string in the socket body.

And finally we attach the trigger to one table (or maybe we need to do it to more than one table)

CREATE TRIGGER myTrigger
  AFTER INSERT OR UPDATE OR DELETE
  ON dummy.myTable
  FOR EACH ROW
  EXECUTE PROCEDURE dummy.myTriggerToSendSockets();

And that’s all. Now we can use one simple TCP socket server to handle those requests. Let me show you different examples of TCP servers with different languages. As we can see all are different implementations of Reactor pattern. We can use, for example:

node.js:

var net = require('net');

var host = 'localhost';
var port = 26200;

var server = net.createServer(function (socket) {
    socket.on('data', function(buffer) {
        // do whatever that we want with buffer
    });
});

server.listen(port, host);

python (with Twisted):

from twisted.internet import reactor, protocol

HOST = 'localhost'
PORT = 26200

class MyServer(protocol.Protocol):
    def dataReceived(self, data):
        # do whatever that we want with data
        pass

class MyServerFactory(protocol.Factory):
    def buildProtocol(self, addr):
        return MyServer()

reactor.listenTCP(PORT, MyServerFactory(), interface=HOST)
reactor.run()

(I know that we can create the Python’s TCP server without Twisted, but if don’t use it maybe someone will angry with me. Probably he is angry right now because I put the node.js example first :))

php (with react):

<?php
include __DIR__ . '/vendor/autoload.php';

$host = 'localhost';
$port = 26200;

$loop   = React\EventLoop\Factory::create();
$socket = new React\Socket\Server($loop);

$socket->on('connection', function ($conn) {
    $conn->on('data', function ($data) {
        // do whatever we want with data
        }
    );
});

$socket->listen($port, $host);
$loop->run();

You also can use xinet.d to handle the TCP inbound connections.

How to call shell programs as functions with PHP

I’m a big fan of Symfony’s Process Component. I’ve used intensively this component within a project and I noticed that I needed a wrapper to avoid to write again and again the same code. Suddenly a cool python library came to my head: sh. With python’s sh we can call any program as if it were a function:

from sh import ifconfig
print(ifconfig("wlan0"))

Outputs:

wlan0   Link encap:Ethernet  HWaddr 00:00:00:00:00:00
        inet addr:192.168.1.100  Bcast:192.168.1.255  Mask:255.255.255.0
        inet6 addr: ffff::ffff:ffff:ffff:fff/64 Scope:Link
        UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
        RX packets:0 errors:0 dropped:0 overruns:0 frame:0
        TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
        collisions:0 txqueuelen:1000
        RX bytes:0 (0 GB)  TX bytes:0 (0 GB)

So I decided to develop something similar in PHP. This library is not exactly the same than python one. Python’s sh allows more cool things such as non-blocking processes, baking, … not available in my PHP one’s, but at least I can call shell programs as functions in a simple way (and that’s was my scope). Let’s start.

One simple example of Process:

use Symfony\Component\Process\Process;

$process = new Process('-latr ~');
$process->setTimeout(3600);
$process->run();

echo $process->getOutput();

With sh library we can do:

use Sh/Sh;

$sh  = new Sh();
echo $sh->ls('-latr ~');

You can check the source code in github, but it’s very simple one. Basically it’s a parser that creates the command line string, and another class that calls to the parser and sends the output to Process component. Whit the magic function __call we can use shell commands as functions.

The command’s arguments can be one string ‘-latr ~’ or one array [‘-latr’, ‘~’]. You can see more example in the unit tests here

Symfony/Process also allows us to get feedback in real time:

use Symfony\Component\Process\Process;

$process = new Process('ls -lsa');
$process->run(function ($type, $buffer) {
    if ('err' === $type) {
        echo 'ERR > '.$buffer;
    } else {
        echo 'OUT > '.$buffer;
    }
});

Sh uses this feature, so we can do things like that:

$sh->tail('/var/log/messages', function ($buffer)  {
    echo $buffer;
});

We can see more examples here:

<?php
error_reporting(-1);
include __DIR__ . '/../vendor/autoload.php';
use Sh\Sh;

echo Sh::factory()->runCommnad('notify-send', ['-t', 5000, 'title', 'HOLA']);
$sh  = new Sh();
echo $sh->ifconfig("eth0");
echo $sh->ls('-latr ~');
echo $sh->ls(['-latr', '~']);
$sh->tail('-f /var/log/apache2/access.log', function ($buffer)  {
    echo $buffer;
});

As I said before the library is in github and also you can use with composer:

require: "gonzalo123/sh": "dev-master"

Updated!

Now Sh library supports chained arguments (baking)

// chainable commands (baking)
$sh->ssh(array('myserver.com', '-p' => 1393))->whoami();
// executes: ssh myserver.com -p 1393 whoami

$sh->ssh(array('myserver.com', '-p' => 1393))->tail(array("/var/log/dumb_daemon.log", 'n' => 100));
// executes: ssh myserver.com -p 1393 tail /var/log/dumb_daemon.log -n 100
});

Building a FTP client library with PHP

In my daily work I need to connect very often to FTP servers. Put files, read, list and things like that. I normally use the standard PHP functions for Ftp it’s pretty straight forward to use them. Just enable it within our installation (–enable-ftp) and it’s ready to use them. But last Sunday it was raining again and I start with this simple library.

Lets connect to a FTP server, switch to passive mode, put a file from one real file stored in our local filesystem and delete it.

use FtpLib\Ftp,
    FtpLib\File;

list($host, $user, $pass) = include __DIR__ . "/credentials.php";

$ftp = new Ftp($host, $user, $pass);
$ftp->connect();
$ftp->setPasv();

$file = $ftp->putFileFromPath(__DIR__ . '/fixtures/foo');
echo $file->getName();
echo $file->getContent();
$file->delete();

Now the same, but without a real file. We are going to create the file on-the-fly from one string:

use FtpLib\Ftp,
    FtpLib\File;

list($host, $user, $pass) = include __DIR__ . "/credentials.php";

$ftp = new Ftp($host, $user, $pass);
$ftp->connect();
$ftp->setPasv();

$file = $ftp->putFileFromString('bar', 'bla, bla, bla');
echo $file->getName();
echo $file->getContent();
$file->delete();

We also can create directories, change the working directory and delete folders in the FTP server with a fluent interface (I love fluent interfaces, indeed):

$ftp->mkdir('directory')
  ->chdir('directory')
  ->putFileFromString('newFile', 'bla, bla')
  ->delete();

$ftp->rmdir('directory');

And finally we can iterate files in the FTP (I must admit that this feature was the main purpose of the library)

$ftp->getFiles(function (File $file) use ($ftp) {
    switch($file->getName()) {
        case 'file1':
            $file->delete();
            break;
        case 'file2':
            $ftp->mkdir('backup')->chdir('backup')->putFileFromString($file->getName(), $file->getContent());
            break;
    }
});

And that’s all. You can find the library in github and you also can use it with composer.

"gonzalo123/ftplib": "dev-master"

You can also see usage examples within the unit tests

Managing Windows services with Symfony/Process and PHP

Sometimes I need to stop/start remote Windows services with PHP. It’s quite easy to do it with net commnand. This command is a tool for administration of Samba and remote CIFS servers. It’s pretty straightforward to handle them from Linux command line:

net rpc service --help
Usage:
net rpc service list
    View configured Win32 services
net rpc service start
    Start a service
net rpc service stop
    Stop a service
net rpc service pause
    Pause a service
net rpc service resume
    Resume a service
net rpc service status
    View current status of a service
net rpc service delete
    Deletes a service
net rpc service create
    Creates a service

Today we are going to create a PHP wrapper for this tool. Our NetService library will have two classes: One Parser and one Service class.

The Parser’s responsibility will be create the command line instruction. I will use Behat in the developing process of Parser class. Here we can see the feature file:

Feature: command line parser

  Scenario: net service list
    Given windows server host called "windowshost.com"
    And credentials are "myDomanin/user%password"
    And action is "list"
    Then command line is "net rpc service list -S windowshost.com -U myDomanin/user%password"

  Scenario: net service start
    Given windows server host called "windowshost.com"
    And service name called "ServiceName"
    And credentials are "myDomanin/user%password"
    And action is "start"
    Then command line is "net rpc service start ServiceName -S windowshost.com -U myDomanin/user%password"

  Scenario: net service stop
    Given windows server host called "windowshost.com"
    And service name called "ServiceName"
    And credentials are "myDomanin/user%password"
    And action is "stop"
    Then command line is "net rpc service stop ServiceName -S windowshost.com -U myDomanin/user%password"

  Scenario: net service pause
    Given windows server host called "windowshost.com"
    And service name called "ServiceName"
    And credentials are "myDomanin/user%password"
    And action is "pause"
    Then command line is "net rpc service pause ServiceName -S windowshost.com -U myDomanin/user%password"

  Scenario: net service resume
    Given windows server host called "windowshost.com"
    And service name called "ServiceName"
    And credentials are "myDomanin/user%password"
    And action is "resume"
    Then command line is "net rpc service resume ServiceName -S windowshost.com -U myDomanin/user%password"

  Scenario: net service status
    Given windows server host called "windowshost.com"
    And service name called "ServiceName"
    And credentials are "myDomanin/user%password"
    And action is "status"
    Then command line is "net rpc service status ServiceName -S windowshost.com -U myDomanin/user%password"

The implementation of the feature file:

namespace NetService;

class Parser
{
    private $host;
    private $credentials;

    public function __construct($host, $credentials)
    {
        $this->host        = $host;
        $this->credentials = $credentials;
    }

    public function getCommandLineForAction($action, $service = NULL)
    {
        if (!is_null($service)) $service = " {$service}";
        return "net rpc service {$action}{$service} -S {$this->host} -U {$this->credentials}";
    }
}

and finally our Service class:

namespace NetService;

use Symfony\Component\Process\Process,
    NetService\Parser;

class Service
{
    private $parser;
    private $timeout;

    const START = 'start';
    const STOP = 'stop';
    const STATUS = 'status';
    const LIST_SERVICES = 'list';
    const PAUSE = 'pause';
    const RESUME = 'resume';

    const DEFAULT_TIMEOUT = 3600;

    public function __construct(Parser $parser)
    {
        $this->parser = $parser;
        $this->timeout = self::DEFAULT_TIMEOUT;
    }

    public function start($service)
    {
        return $this->runProcess($this->parser->getCommandLineForAction(self::START, $service));
    }

    public function stop($service)
    {
        return $this->runProcess($this->parser->getCommandLineForAction(self::STOP, $service));
    }

    public function pause($service)
    {
        return $this->runProcess($this->parser->getCommandLineForAction(self::PAUSE, $service));
    }

    public function resume($service)
    {
        return $this->runProcess($this->parser->getCommandLineForAction(self::RESUME, $service));
    }

    public function status($service)
    {
        return $this->runProcess($this->parser->getCommandLineForAction(self::STATUS, $service));
    }

    public function listServices()
    {
        return $this->runProcess($this->parser->getCommandLineForAction(self::LIST_SERVICES));
    }

    public function isRunning($service)
    {
        $status = explode("\n", $this->status($service));
        if (isset($status[0]) && strpos(strtolower($status[0]), "running") !== FALSE) {
            return TRUE;
        } else {
            return FALSE;
        }
    }

    public function setTimeout($timeout)
    {
        $this->timeout = $timeout;
    }

    private function runProcess($commandLine)
    {
        $process = new Process($commandLine);
        $process->setTimeout($this->timeout);
        $process->run();

        if (!$process->isSuccessful()) {
            throw new RuntimeException($process->getErrorOutput());
        }

        return $process->getOutput();
    }

    private function parseStatus($status)
    {
        return explode("\n", $status);
    }
}

And that’s all. Now a couple of examples:

include __DIR__ . '/../vendor/autoload.php';

use NetService\Service,
    NetService\Parser;

$host        = 'windowshost.com';
$serviceName = 'ServiceName';
$credentials = '{domain}/{user}%{password}';

$service = new Service(new Parser($host, $credentials));

if ($service->isRunning($serviceName)) {
    echo "Service is running. Let's stop";
    $service->stop($serviceName);

} else {
    echo "Service isn't running. Let's start";
    $service->start($serviceName);
}

//dumps status output
echo $service->status($serviceName);
include __DIR__ . '/../vendor/autoload.php';

use NetService\Service,
    NetService\Parser;

$host        = 'windowshost.com';
$credentials = '{domain}/{user}%{password}';

$service = new Service(new Parser($host, $credentials));
echo $service->listServices();

You can see the full code in github here. The package is also available for composer at Packaist.