Merge pull request #86 from jigarius/feature/handle-sigint

Handle SIGINT gracefully

.docker/main/Dockerfile

@@ -11,6 +11,9 @@ RUN cp "$PHP_INI_DIR/php.ini-development" "$PHP_INI_PATH" \
     && pear config-set php_ini "$PHP_INI_PATH" \
     && pecl install --force xdebug
 
+RUN docker-php-ext-configure pcntl --enable-pcntl \
+  && docker-php-ext-install pcntl
+
 # Provision Drall.
 COPY . /opt/drall
 

README.md

@@ -97,6 +97,13 @@ command just like version 1.x.
 - `drall exec:drush ...` is now `drall exec drush ...`
 - `drall exec:shell ...` is now `drall exec ...`
 
+#### Interrupting a command
+
+When `drall exec` receives a signal to interrupt (usually `ctrl + c`), Drall
+stops after processing the site that is currently being processed. This
+prevents the current command from terminating abruptly. However, if a second
+interrupt signal is received, then Drall stops immediately.
+
 #### Drush with @@dir
 
 In this method, the `--uri` option is sent to `drush`.

src/Command/BaseCommand.php

@@ -2,6 +2,7 @@
 
 namespace Drall\Command;
 
+use Drall\Service\SiteDetector;
 use Drall\Trait\SiteDetectorAwareTrait;
 use Psr\Log\LoggerAwareTrait;
 use Symfony\Component\Console\Command\Command;
@@ -68,6 +69,12 @@ protected function preExecute(InputInterface $input, OutputInterface $output) {
       $this->logger = new ConsoleLogger($output);
     }
 
+    if (!$this->hasSiteDetector()) {
+      $root = $input->getParameterOption('--root') ?: getcwd();
+      $siteDetector = SiteDetector::create($root);
+      $this->setSiteDetector($siteDetector);
+    }
+
     if ($group = $this->getDrallGroup($input)) {
       $this->logger->debug('Detected group: {group}', ['group' => $group]);
     }

src/Command/ExecCommand.php

@@ -12,6 +12,7 @@
 use Drall\Model\EnvironmentId;
 use Drall\Model\Placeholder;
 use Drall\Model\RawCommand;
+use Drall\Trait\SignalAwareTrait;
 use Symfony\Component\Console\Helper\ProgressBar;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
@@ -24,6 +25,8 @@
  */
 class ExecCommand extends BaseCommand {
 
+  use SignalAwareTrait;
+
   /**
    * Maximum number of Drall workers.
    *
@@ -144,17 +147,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
       return 0;
     }
 
-    // Determine number of workers.
-    $workers = $input->getOption('drall-workers');
-
-    if ($workers > self::WORKER_LIMIT) {
-      $this->logger->warning('Limiting workers to {count}, which is the maximum.', ['count' => self::WORKER_LIMIT]);
-      $workers = self::WORKER_LIMIT;
-    }
-
-    if ($workers > 1) {
-      $this->logger->notice("Using {count} workers.", ['count' => $workers]);
-    }
+    $workers = $this->getWorkerCount($input);
 
     // Display commands without executing them.
     if ($input->getOption('drall-no-execute')) {
@@ -173,11 +166,40 @@ protected function execute(InputInterface $input, OutputInterface $output): int
     );
     $exitCode = 0;
 
-    Loop::run(function () use ($values, $command, $placeholder, $output, $progressBar, $workers, &$exitCode) {
+    // Handle interruption signals to stop Drall gracefully.
+    $isStopping = FALSE;
+    $this->registerInterruptionListener(function () use (&$isStopping, $output) {
+      $output->writeln('');
+
+      // If a previous SIGINT was received, then stop immediately.
+      if ($isStopping) {
+        $this->logger->error('Interrupted by user.');
+        exit(1);
+      }
+
+      // Prepare to stop after the current item is processed.
+      $this->logger->warning('Stopping after current item.');
+      $isStopping = TRUE;
+    });
+
+    Loop::run(function () use (
+      $values,
+      $command,
+      $placeholder,
+      $output,
+      $progressBar,
+      $workers,
+      &$exitCode,
+      &$isStopping
+    ) {
       yield ConcurrentIterator\each(
         Iterator\fromIterable($values),
         new LocalSemaphore($workers),
-        function ($value) use ($command, $placeholder, $output, $progressBar, &$exitCode) {
+        function ($value) use ($command, $placeholder, $output, $progressBar, &$exitCode, &$isStopping) {
+          if ($isStopping) {
+            return;
+          }
+
           $sCommand = Placeholder::replace([$placeholder->value => $value], $command);
           $process = new Process("($sCommand) 2>&1", getcwd());
 
@@ -199,9 +221,17 @@ function ($value) use ($command, $placeholder, $output, $progressBar, &$exitCode
       );
     });
 
-    $progressBar->finish();
+    if (!$isStopping) {
+      $progressBar->finish();
+    }
+
     $output->writeln('');
 
+    if ($isStopping) {
+      $this->logger->error('Interrupted by user.');
+      return 1;
+    }
+
     return $exitCode;
   }
 
@@ -227,6 +257,30 @@ protected function getCommand(): RawCommand {
     return $command;
   }
 
+  /**
+   * Gets the number of workers that should be used.
+   *
+   * @param \Symfony\Component\Console\Input\InputInterface $input
+   *   The input.
+   *
+   * @return int
+   *   Number of workers to be used.
+   */
+  protected function getWorkerCount(InputInterface $input): int {
+    $result = $input->getOption('drall-workers');
+
+    if ($result > self::WORKER_LIMIT) {
+      $this->logger->warning('Limiting workers to {count}, which is the maximum.', ['count' => self::WORKER_LIMIT]);
+      $result = self::WORKER_LIMIT;
+    }
+
+    if ($result > 1) {
+      $this->logger->notice("Using {count} workers.", ['count' => $result]);
+    }
+
+    return $result;
+  }
+
   /**
    * Get unique placeholder from a command.
    */

src/Drall.php

@@ -2,19 +2,14 @@
 
 namespace Drall;
 
-use Consolidation\SiteAlias\SiteAliasManager;
 use Drall\Command\ExecCommand;
 use Drall\Command\SiteAliasesCommand;
 use Drall\Command\SiteDirectoriesCommand;
 use Drall\Command\SiteKeysCommand;
 use Drall\Model\EnvironmentId;
-use Drall\Service\SiteDetector;
 use Drall\Trait\SiteDetectorAwareTrait;
-use DrupalFinder\DrupalFinder;
-use Drush\SiteAlias\SiteAliasFileLoader;
 use Symfony\Component\Console\Application;
 use Symfony\Component\Console\Exception\CommandNotFoundException;
-use Symfony\Component\Console\Input\ArgvInput;
 use Symfony\Component\Console\Input\InputDefinition;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Input\InputOption;
@@ -31,39 +26,16 @@ final class Drall extends Application {
   /**
    * Creates a Phpake Application instance.
    */
-  public function __construct(
-    SiteDetector $siteDetector = NULL,
-    ?InputInterface $input = NULL
-  ) {
+  public function __construct() {
     parent::__construct();
     $this->setName(self::NAME);
     $this->setVersion(self::VERSION);
     $this->setAutoExit(FALSE);
 
-    // @todo Instead of using $input to create a SiteDetector here, we can
-    //   create the SiteDetector in BaseCommand::preExecute(). That way,
-    //   we won't need this extra dependency injection, thereby simplifying
-    //   the code and the tests.
-    $input = $input ?? new ArgvInput();
-    $root = $input->getParameterOption('--root') ?: getcwd();
-    $siteDetector ??= $this->createDefaultSiteDetector($root);
-    $this->setSiteDetector($siteDetector);
-
-    $cmd = new SiteDirectoriesCommand();
-    $cmd->setSiteDetector($siteDetector);
-    $this->add($cmd);
-
-    $cmd = new SiteKeysCommand();
-    $cmd->setSiteDetector($siteDetector);
-    $this->add($cmd);
-
-    $cmd = new SiteAliasesCommand();
-    $cmd->setSiteDetector($siteDetector);
-    $this->add($cmd);
-
-    $cmd = new ExecCommand();
-    $cmd->setSiteDetector($siteDetector);
-    $this->add($cmd);
+    $this->add(new SiteDirectoriesCommand());
+    $this->add(new SiteKeysCommand());
+    $this->add(new SiteAliasesCommand());
+    $this->add(new ExecCommand());
   }
 
   protected function configureIO(InputInterface $input, OutputInterface $output) {
@@ -110,16 +82,6 @@ protected function getDefaultInputDefinition(): InputDefinition {
     return $definition;
   }
 
-  private function createDefaultSiteDetector(string $root): SiteDetector {
-    $drupalFinder = new DrupalFinder();
-    $drupalFinder->locateRoot($root);
-
-    $siteAliasManager = new SiteAliasManager(new SiteAliasFileLoader());
-    $siteAliasManager->addSearchLocation($drupalFinder->getComposerRoot() . '/drush/sites');
-
-    return new SiteDetector($drupalFinder, $siteAliasManager);
-  }
-
   public function find($name) {
     try {
       return parent::find($name);

src/Service/SiteDetector.php

@@ -4,11 +4,13 @@
 
 use Consolidation\Filter\FilterOutputData;
 use Consolidation\Filter\LogicalOpFactory;
+use Consolidation\SiteAlias\SiteAliasManager;
 use Consolidation\SiteAlias\SiteAliasManagerAwareTrait;
 use Consolidation\SiteAlias\SiteAliasManagerInterface;
 use Drall\Model\SitesFile;
 use Drall\Trait\DrupalFinderAwareTrait;
 use DrupalFinder\DrupalFinder;
+use Drush\SiteAlias\SiteAliasFileLoader;
 
 class SiteDetector {
 
@@ -211,6 +213,25 @@ private function filter(
     return $result;
   }
 
+  /**
+   * Create a SiteDetector given a Drupal project root.
+   *
+   * @param string $root
+   *   Composer project root directory.
+   *
+   * @return static
+   *   A SiteDetector.
+   */
+  public static function create(string $root): static {
+    $drupalFinder = new DrupalFinder();
+    $drupalFinder->locateRoot($root);
+
+    $siteAliasManager = new SiteAliasManager(new SiteAliasFileLoader());
+    $siteAliasManager->addSearchLocation($drupalFinder->getComposerRoot() . '/drush/sites');
+
+    return new SiteDetector($drupalFinder, $siteAliasManager);
+  }
+
   /**
    * Detects sites in a "sites" directory.
    *

src/Trait/SignalAwareTrait.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace Drall\Trait;
+
+trait SignalAwareTrait {
+
+  /**
+   * Register a signal listener.
+   *
+   * @param int $signo
+   *   Signal Number.
+   * @param callable $handler
+   *   A callable event listener.
+   *
+   * @return bool
+   *   True if the listener was registered.
+   */
+  protected function registerSignalListener(int $signo, callable $handler): bool {
+    if (!extension_loaded('pcntl')) {
+      return FALSE;
+    }
+
+    declare(ticks = 1);
+    \pcntl_signal($signo, $handler);
+
+    return TRUE;
+  }
+
+  /**
+   * Register a listener for SIGINT.
+   *
+   * @param callable $handler
+   *   A callable event listener.
+   *
+   * @return bool
+   *   True if the listener was registered.
+   */
+  protected function registerInterruptionListener(callable $handler): bool {
+    if (!defined('SIGINT')) {
+      return FALSE;
+    }
+
+    return self::registerSignalListener(SIGINT, $handler);
+  }
+
+}

src/Trait/SiteDetectorAwareTrait.php

@@ -30,7 +30,7 @@ public function setSiteDetector(SiteDetector $siteDetector) {
   public function siteDetector(): SiteDetector {
     if (!$this->hasSiteDetector()) {
       throw new \BadMethodCallException(
-        'A site detecetor instance must first be assigned'
+        'A site detector instance must first be assigned'
       );
     }
 

test/Unit/Command/ExecCommandTest.php

@@ -27,10 +27,12 @@ public function testNoSitesFound() {
       ->method('getSiteDirNames')
       ->willReturn([]);
 
-    $app = new Drall($siteDetectorMock);
+    $app = new Drall();
     $input = ['cmd' => 'cat @@dir'];
-    $command = $app->find('exec')
-      ->setArgv(self::arrayInputAsArgv($input));
+    /** @var \Drall\Command\ExecCommand $command */
+    $command = $app->find('exec');
+    $command->setSiteDetector($siteDetectorMock);
+    $command->setArgv(self::arrayInputAsArgv($input));
     $tester = new CommandTester($command);
     $tester->execute($input);
 
@@ -54,11 +56,12 @@ public function testNonZeroExitCode() {
       ->method('getSiteAliasNames')
       ->willReturn(['@splinter', '@shredder']);
 
-    $app = new Drall($siteDetectorMock);
+    $app = new Drall();
     $input = ['cmd' => 'drush @@site.dev core:rebuild'];
-    /** @var ExecCommand $command */
-    $command = $app->find('exec')
-      ->setArgv(self::arrayInputAsArgv($input));
+    /** @var \Drall\Command\ExecCommand $command */
+    $command = $app->find('exec');
+    $command->setSiteDetector($siteDetectorMock);
+    $command->setArgv(self::arrayInputAsArgv($input));
     $tester = new CommandTester($command);
 
     $this->assertEquals(1, $tester->execute($input));
@@ -95,7 +98,7 @@ public function testWithMixedPlaceholders() {
   }
 
   /**
-   * Drall caps the maximum number of workers.
+   * Drall caps the maximum number of workers to pre-determined limit.
    */
   public function testWorkerLimit() {
     $input = [