feat(daemon-mode): Daemonize Swoole HTTP server

See commands:

```bash
$ bin/console swoole:server:start  # starts swoole http server in background
$ bin/console swoole:server:stop   # stops swoole http server running in
background
$ bin/console swoole:server:reload # reloads swoole http server's
workers and project classes (not infrastructure/vendor ones)
```

.gitignore

@@ -1,3 +1,4 @@
 /vendor
+swoole.pid
 .php_cs.cache
 clover.xml

src/Bridge/Symfony/Bundle/Command/AbstractServerStartCommand.php

@@ -26,7 +26,7 @@ abstract class AbstractServerStartCommand extends Command
     private $serverFactory;
     private $serverConfiguration;
     private $bootManager;
-    private $parameterBag;
+    protected $parameterBag;
 
     /**
      * @param HttpServer              $server
@@ -75,8 +75,7 @@ protected function configure(): void
             ->addOption('serve-static', 's', InputOption::VALUE_NONE, 'Enables serving static content from public directory.')
             ->addOption('public-dir', null, InputOption::VALUE_REQUIRED, 'Public directory', $this->getDefaultPublicDir())
             ->addOption('trusted-hosts', null, InputOption::VALUE_REQUIRED, 'Trusted hosts', $this->parameterBag->get('swoole.http_server.trusted_hosts'))
-            ->addOption('trusted-proxies', null, InputOption::VALUE_REQUIRED, 'Trusted proxies', $this->parameterBag->get('swoole.http_server.trusted_proxies'))
-        ;
+            ->addOption('trusted-proxies', null, InputOption::VALUE_REQUIRED, 'Trusted proxies', $this->parameterBag->get('swoole.http_server.trusted_proxies'));
     }
 
     /**
@@ -95,6 +94,11 @@ final protected function execute(InputInterface $input, OutputInterface $output)
 
         $this->prepareServerConfiguration($this->serverConfiguration, $input);
 
+        if ($this->server->isRunning()) {
+            $io->error('Swoole HTTP Server is already running');
+            exit(1);
+        }
+
         $this->server->attach($this->serverFactory->make(
             $this->serverConfiguration->getDefaultSocket(),
             $this->serverConfiguration->getRunningMode()
@@ -109,11 +113,7 @@ final protected function execute(InputInterface $input, OutputInterface $output)
         $io->success(\sprintf('Swoole HTTP Server started on http://%s', $this->serverConfiguration->getDefaultSocket()->addressPort()));
         $io->table(['Configuration', 'Values'], $this->prepareConfigurationRowsToPrint($this->serverConfiguration, $runtimeConfiguration));
 
-        if ($this->server->start()) {
-            $io->success('Swoole HTTP Server has been successfully shutdown.');
-        } else {
-            $io->error('Failure during starting Swoole HTTP Server.');
-        }
+        $this->startServer($this->serverConfiguration, $this->server, $io);
     }
 
     /**
@@ -233,4 +233,20 @@ protected function prepareConfigurationRowsToPrint(HttpServerConfiguration $serv
 
         return $rows;
     }
+
+    /**
+     * @param HttpServerConfiguration $serverConfiguration
+     * @param HttpServer              $server
+     * @param SymfonyStyle            $io
+     *
+     * @throws \Assert\AssertionFailedException
+     */
+    protected function startServer(HttpServerConfiguration $serverConfiguration, HttpServer $server, SymfonyStyle $io): void
+    {
+        if ($server->start()) {
+            $io->success('Swoole HTTP Server has been successfully shutdown.');
+        } else {
+            $io->error('Failure during starting Swoole HTTP Server.');
+        }
+    }
 }

src/Bridge/Symfony/Bundle/Command/ServerReloadCommand.php

@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace K911\Swoole\Bridge\Symfony\Bundle\Command;
+
+use K911\Swoole\Server\HttpServer;
+use K911\Swoole\Server\HttpServerConfiguration;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
+use Throwable;
+
+final class ServerReloadCommand extends Command
+{
+    private $server;
+    private $serverConfiguration;
+    private $parameterBag;
+
+    public function __construct(
+        HttpServer $server,
+        HttpServerConfiguration $serverConfiguration,
+        ParameterBagInterface $parameterBag)
+    {
+        $this->server = $server;
+        $this->serverConfiguration = $serverConfiguration;
+        $this->parameterBag = $parameterBag;
+
+        parent::__construct();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function configure(): void
+    {
+        $this->setName('swoole:server:reload')
+            ->setDescription("Reloads a local Swoole HTTP server's workers running in background. It will reload only classes not loaded before server initialization.")
+            ->addOption('pid_file', null, InputOption::VALUE_REQUIRED, 'Pid file', $this->parameterBag->get('kernel.project_dir').'/var/swoole.pid');
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @throws \Assert\AssertionFailedException
+     */
+    protected function execute(InputInterface $input, OutputInterface $output): void
+    {
+        $io = new SymfonyStyle($input, $output);
+
+        $this->serverConfiguration->daemonize($input->getOption('pid_file'));
+
+        try {
+            $this->server->reload();
+        } catch (Throwable $ex) {
+            $io->error($ex->getMessage());
+            exit(1);
+        }
+
+        $io->success('Swoole HTTP Server\'s workers reloaded successfully');
+    }
+}

src/Bridge/Symfony/Bundle/Command/ServerRunCommand.php

@@ -12,7 +12,7 @@ final class ServerRunCommand extends AbstractServerStartCommand
     protected function configure(): void
     {
         $this->setName('swoole:server:run')
-            ->setDescription('Runs a local swoole http server');
+            ->setDescription('Runs a local Swoole HTTP server.');
 
         parent::configure();
     }

src/Bridge/Symfony/Bundle/Command/ServerStartCommand.php

@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+
+namespace K911\Swoole\Bridge\Symfony\Bundle\Command;
+
+use K911\Swoole\Server\HttpServer;
+use K911\Swoole\Server\HttpServerConfiguration;
+use RuntimeException;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\ConsoleOutput;
+use Symfony\Component\Console\Output\StreamOutput;
+use Symfony\Component\Console\Style\OutputStyle;
+use Symfony\Component\Console\Style\SymfonyStyle;
+use function K911\Swoole\get_object_property;
+
+final class ServerStartCommand extends AbstractServerStartCommand
+{
+    /**
+     * {@inheritdoc}
+     */
+    protected function configure(): void
+    {
+        $this->setName('swoole:server:start')
+            ->setDescription('Runs a local Swoole HTTP server in background.')
+            ->addOption('pid_file', null, InputOption::VALUE_REQUIRED, 'Pid file', $this->parameterBag->get('kernel.project_dir').'/var/swoole.pid');
+
+        parent::configure();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function prepareServerConfiguration(HttpServerConfiguration $serverConfiguration, InputInterface $input): void
+    {
+        /** @var string|null $pidFile */
+        $pidFile = $input->getOption('pid_file');
+        $serverConfiguration->daemonize($pidFile);
+
+        parent::prepareServerConfiguration($serverConfiguration, $input);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function startServer(HttpServerConfiguration $serverConfiguration, HttpServer $server, SymfonyStyle $io): void
+    {
+        if (!$serverConfiguration->existsPidFile() && !\touch($serverConfiguration->getPidFile())) {
+            throw new RuntimeException(\sprintf('Could not create pid file "%s".', $serverConfiguration->getPid()));
+        }
+
+        // Output stream `php://stdout` must be closed
+        $this->forceCloseOutputStream($io);
+
+        $server->start();
+    }
+
+    private function forceCloseOutputStream(SymfonyStyle $io): void
+    {
+        /** @var ConsoleOutput $consoleOutput */
+        $consoleOutput = &get_object_property($io, 'output', OutputStyle::class);
+
+        /** @var resource $stream */
+        $stream = &get_object_property($consoleOutput, 'stream', StreamOutput::class);
+
+        \fclose($stream);
+    }
+}

src/Bridge/Symfony/Bundle/Command/ServerStopCommand.php

@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace K911\Swoole\Bridge\Symfony\Bundle\Command;
+
+use K911\Swoole\Server\HttpServer;
+use K911\Swoole\Server\HttpServerConfiguration;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
+use Throwable;
+
+final class ServerStopCommand extends Command
+{
+    private $server;
+    private $serverConfiguration;
+    private $parameterBag;
+
+    public function __construct(
+        HttpServer $server,
+        HttpServerConfiguration $serverConfiguration,
+        ParameterBagInterface $parameterBag)
+    {
+        $this->server = $server;
+        $this->serverConfiguration = $serverConfiguration;
+        $this->parameterBag = $parameterBag;
+
+        parent::__construct();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function configure(): void
+    {
+        $this->setName('swoole:server:stop')
+            ->setDescription('Stops a local Swoole HTTP server running in background')
+            ->addOption('pid_file', null, InputOption::VALUE_REQUIRED, 'Pid file', $this->parameterBag->get('kernel.project_dir').'/var/swoole.pid');
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @throws \Assert\AssertionFailedException
+     */
+    protected function execute(InputInterface $input, OutputInterface $output): void
+    {
+        $io = new SymfonyStyle($input, $output);
+
+        $this->serverConfiguration->daemonize($input->getOption('pid_file'));
+
+        try {
+            $this->server->shutdown();
+        } catch (Throwable $ex) {
+            $io->error($ex->getMessage());
+            exit(1);
+        }
+
+        $io->success('Swoole server shutdown successfully');
+    }
+}

src/Bridge/Symfony/Bundle/Resources/config/services.yaml

@@ -39,6 +39,17 @@ services:
         arguments:
             $configurator: '@K911\Swoole\Server\Configurator\WithRequestHandler'
 
+    'K911\Swoole\Bridge\Symfony\Bundle\Command\ServerStartCommand':
+        tags: ['console.command']
+        arguments:
+            $serverFactory: '@swoole_bundle.server.http_server.factory'
+
+    'K911\Swoole\Bridge\Symfony\Bundle\Command\ServerStopCommand':
+        tags: ['console.command']
+
+    'K911\Swoole\Bridge\Symfony\Bundle\Command\ServerReloadCommand':
+        tags: ['console.command']
+
     'K911\Swoole\Bridge\Symfony\Bundle\Command\ServerRunCommand':
         tags: ['console.command']
         arguments:

src/Server/HttpServer.php

@@ -5,12 +5,13 @@
 namespace K911\Swoole\Server;
 
 use Assert\Assertion;
+use RuntimeException;
 use Swoole\Http\Server;
+use Swoole\Process;
+use Throwable;
 
 final class HttpServer
 {
-    private const SWOOLE_HTTP_SERVER_HAS_NOT_BEEN_INITIALIZED_MESSAGE = 'Swoole HTTP Server has not been setup yet. Please use setup or attach method.';
-
     /**
      * @var Server|null
      */
@@ -46,7 +47,7 @@ public function attach(Server $server): void
      */
     public function start(): bool
     {
-        Assertion::isInstanceOf($this->server, Server::class, self::SWOOLE_HTTP_SERVER_HAS_NOT_BEEN_INITIALIZED_MESSAGE);
+        Assertion::isInstanceOf($this->server, Server::class, 'Swoole HTTP Server has not been setup yet. Please use attach method.');
 
         return $this->running = $this->server->start();
     }
@@ -56,16 +57,46 @@ public function start(): bool
      */
     public function shutdown(): void
     {
-        Assertion::isInstanceOf($this->server, Server::class, self::SWOOLE_HTTP_SERVER_HAS_NOT_BEEN_INITIALIZED_MESSAGE);
+        if ($this->server instanceof Server) {
+            $this->server->shutdown();
+        } elseif ($this->isRunningInBackground()) {
+            Process::kill($this->configuration->getPid(), 15); // SIGTERM
+        } else {
+            throw new RuntimeException('Swoole HTTP Server has not been running.');
+        }
+    }
 
-        $this->server->shutdown();
+    /**
+     * @throws \Assert\AssertionFailedException
+     */
+    public function reload(): void
+    {
+        if ($this->server instanceof Server) {
+            $this->server->reload();
+        } elseif ($this->isRunningInBackground()) {
+            Process::kill($this->configuration->getPid(), 10); // SIGUSR1
+        } else {
+            throw new RuntimeException('Swoole HTTP Server has not been running.');
+        }
     }
 
     /**
      * @return bool
      */
     public function isRunning(): bool
     {
-        return $this->running || $this->configuration->existsPidFile();
+        return $this->running || $this->isRunningInBackground();
+    }
+
+    /**
+     * @return bool
+     */
+    private function isRunningInBackground(): bool
+    {
+        try {
+            return Process::kill($this->configuration->getPid(), 0);
+        } catch (Throwable $ex) {
+            return false;
+        }
     }
 }