Start phd daemons as the correctly configured user and refuse otherwise

Summary:
Fixes T5196
If no phd.user is configured the behaviour is unchanged besides printing a warning when run as root (Usually i would add an exit(1) here but that would break existing installs who do that).
If phd.user is set and the current user is root it will run the daemon as: su USER -c "command" (I'm not sure if this works for every platform needed)
Otherwise it will refuse to start if configured and current user mismatch.

Test Plan: Stopped & Started phd daemon with various users and different phd.user settings including root

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: vinzent, epriestley

Maniphest Tasks: T5196

Differential Revision: https://secure.phabricator.com/D11036

resources/sql/autopatches/20141223.daemonloguser.sql

@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_daemon.daemon_log
+  ADD runningAsUser VARCHAR(255) COLLATE {$COLLATE_TEXT};

src/applications/config/check/PhabricatorSetupCheckDaemons.php

@@ -43,12 +43,47 @@ final class PhabricatorSetupCheckDaemons extends PhabricatorSetupCheck {
         ->addCommand('phabricator/ $ ./bin/phd start');
     }
 
+    $phd_user = PhabricatorEnv::getEnvConfig('phd.user');
     $environment_hash = PhabricatorEnv::calculateEnvironmentHash();
     $all_daemons = id(new PhabricatorDaemonLogQuery())
       ->setViewer(PhabricatorUser::getOmnipotentUser())
       ->withStatus(PhabricatorDaemonLogQuery::STATUS_ALIVE)
       ->execute();
     foreach ($all_daemons as $daemon) {
+
+      if ($phd_user) {
+        if ($daemon->getRunningAsUser() != $phd_user) {
+          $doc_href = PhabricatorEnv::getDocLink(
+            'Managing Daemons with phd');
+
+          $summary = pht(
+            'At least one daemon is currently running as a different '.
+            'user than configured in the Phabricator phd.user setting');
+
+          $message = pht(
+            'A daemon is running as user %s while the Phabricator config '.
+            'specifies phd.user to be %s.'.
+            "\n\n".
+            'Either adjust phd.user to match %s or start '.
+            'the daemons as the correct user. '.
+            "\n\n".
+            'phd Daemons will try to '.
+            'use sudo to start as the configured user. '.
+            'Make sure that the user who starts phd has the correct '.
+            'sudo permissions to start phd daemons as %s',
+            phutil_tag('tt', array(), $daemon->getRunningAsUser()),
+            phutil_tag('tt', array(), $phd_user),
+            phutil_tag('tt', array(), $daemon->getRunningAsUser()),
+            phutil_tag('tt', array(), $phd_user));
+
+          $this->newIssue('daemons.run-as-different-user')
+            ->setName(pht('Daemons are running as the wrong user'))
+            ->setSummary($summary)
+            ->setMessage($message)
+            ->addCommand('phabricator/ $ ./bin/phd restart');
+        }
+      }
+
       if ($daemon->getEnvHash() != $environment_hash) {
         $doc_href = PhabricatorEnv::getDocLink(
           'Managing Daemons with phd');

src/applications/daemon/controller/PhabricatorDaemonLogViewController.php

@@ -163,6 +163,7 @@ final class PhabricatorDaemonLogViewController
     $view->addProperty(pht('Daemon Class'), $daemon->getDaemon());
     $view->addProperty(pht('Host'), $daemon->getHost());
     $view->addProperty(pht('PID'), $daemon->getPID());
+    $view->addProperty(pht('Running as'), $daemon->getRunningAsUser());
     $view->addProperty(pht('Started'), phabricator_datetime($c_epoch, $viewer));
     $view->addProperty(
       pht('Seen'),

src/applications/daemon/event/PhabricatorDaemonEventListener.php

@@ -34,11 +34,13 @@ final class PhabricatorDaemonEventListener extends PhabricatorEventListener {
 
   private function handleLaunchEvent(PhutilEvent $event) {
     $id = $event->getValue('id');
+    $current_user = posix_getpwuid(posix_geteuid());
 
     $daemon = id(new PhabricatorDaemonLog())
       ->setDaemon($event->getValue('daemonClass'))
       ->setHost(php_uname('n'))
       ->setPID(getmypid())
+      ->setRunningAsUser($current_user['name'])
       ->setEnvHash(PhabricatorEnv::calculateEnvironmentHash())
       ->setStatus(PhabricatorDaemonLog::STATUS_RUNNING)
       ->setArgv($event->getValue('argv'))

src/applications/daemon/management/PhabricatorDaemonManagementDebugWorkflow.php

@@ -21,11 +21,17 @@ final class PhabricatorDaemonManagementDebugWorkflow
             'name' => 'argv',
             'wildcard' => true,
           ),
+          array(
+            'name' => 'as-current-user',
+            'help' => 'Run the daemon as the current user '.
+              'instead of the configured phd.user',
+          ),
         ));
   }
 
   public function execute(PhutilArgumentParser $args) {
     $argv = $args->getArg('argv');
+    $run_as_current_user = $args->getArg('as-current-user');
 
     if (!$argv) {
       throw new PhutilArgumentUsageException(
@@ -33,7 +39,11 @@ final class PhabricatorDaemonManagementDebugWorkflow
     }
 
     $daemon_class = array_shift($argv);
-    return $this->launchDaemon($daemon_class, $argv, $is_debug = true);
+    return $this->launchDaemon(
+      $daemon_class,
+      $argv,
+      $is_debug = true,
+      $run_as_current_user);
   }
 
 }

src/applications/daemon/management/PhabricatorDaemonManagementWorkflow.php

@@ -3,6 +3,8 @@
 abstract class PhabricatorDaemonManagementWorkflow
   extends PhabricatorManagementWorkflow {
 
+  private $runDaemonsAsUser = null;
+
   protected final function loadAvailableDaemonClasses() {
     $loader = new PhutilSymbolLoader();
     return $loader
@@ -103,10 +105,37 @@ abstract class PhabricatorDaemonManagementWorkflow
     return head($match);
   }
 
-  protected final function launchDaemon($class, array $argv, $debug) {
+  protected final function launchDaemon(
+    $class,
+    array $argv,
+    $debug,
+    $run_as_current_user = false) {
+
     $daemon = $this->findDaemonClass($class);
     $console = PhutilConsole::getConsole();
 
+    if (!$run_as_current_user) {
+      // Check if the script is started as the correct user
+      $phd_user = PhabricatorEnv::getEnvConfig('phd.user');
+      $current_user = posix_getpwuid(posix_geteuid());
+      $current_user = $current_user['name'];
+      if ($phd_user && $phd_user != $current_user) {
+        if ($debug) {
+          throw new PhutilArgumentUsageException(pht(
+            'You are trying to run a daemon as a nonstandard user, '.
+            'and `phd` was not able to `sudo` to the correct user. '."\n".
+            'Phabricator is configured to run daemons as "%s", '.
+            'but the current user is "%s". '."\n".
+            'Use `sudo` to run as a different user, pass `--as-current-user` '.
+            'to ignore this warning, or edit `phd.user` '.
+            'to change the configuration.', $phd_user, $current_user));
+        } else {
+          $this->runDaemonsAsUser = $phd_user;
+          $console->writeOut(pht('Starting daemons as %s', $phd_user)."\n");
+        }
+      }
+    }
+
     if ($debug) {
       if ($argv) {
         $console->writeOut(
@@ -187,13 +216,41 @@ abstract class PhabricatorDaemonManagementWorkflow
 
       phutil_passthru('(cd %s && exec %C)', $daemon_script_dir, $command);
     } else {
-      $future = new ExecFuture('exec %C', $command);
-      // Play games to keep 'ps' looking reasonable.
-      $future->setCWD($daemon_script_dir);
-      $future->resolvex();
+      try {
+        $this->executeDaemonLaunchCommand(
+          $command,
+          $daemon_script_dir,
+          $this->runDaemonsAsUser);
+      } catch (CommandException $e) {
+        // Retry without sudo
+        $console->writeOut(pht(
+          "sudo command failed. Starting daemon as current user\n"));
+        $this->executeDaemonLaunchCommand(
+          $command,
+          $daemon_script_dir);
+      }
     }
   }
 
+  private function executeDaemonLaunchCommand(
+    $command,
+    $daemon_script_dir,
+    $run_as_user = null) {
+
+    if ($run_as_user) {
+      // If anything else besides sudo should be
+      // supported then insert it here (runuser, su, ...)
+      $command = csprintf(
+        'sudo -En -u %s -- %C',
+        $run_as_user,
+        $command);
+    }
+    $future = new ExecFuture('exec %C', $command);
+    // Play games to keep 'ps' looking reasonable.
+    $future->setCWD($daemon_script_dir);
+    $future->resolvex();
+  }
+
   public static function ignoreSignal($signo) {
     return;
   }

src/applications/daemon/storage/PhabricatorDaemonLog.php

@@ -13,6 +13,7 @@ final class PhabricatorDaemonLog extends PhabricatorDaemonDAO
   protected $daemon;
   protected $host;
   protected $pid;
+  protected $runningAsUser;
   protected $argv;
   protected $explicitArgv = array();
   protected $envHash;
@@ -28,6 +29,7 @@ final class PhabricatorDaemonLog extends PhabricatorDaemonDAO
         'daemon' => 'text255',
         'host' => 'text255',
         'pid' => 'uint32',
+        'runningAsUser' => 'text255?',
         'envHash' => 'bytes40',
         'status' => 'text8',
       ),