Improve robustness and safety

base/HHVMDaemon.php

@@ -17,6 +17,7 @@ public function __construct(private PerfOptions $options) {
     parent::__construct((string) $options->hhvm);
 
     $this->serverType = $options->proxygen ? 'proxygen' : 'fastcgi';
+    $runAsRoot = $options->runAsRoot ? '1' : '0';
 
     $output = [];
     $check_command = implode(
@@ -25,6 +26,8 @@ public function __construct(private PerfOptions $options) {
          $options->hhvm,
          '-v',
          'Eval.Jit=1',
+         '-v',
+         'Server.AllowRunAsRoot='.$runAsRoot,
          __DIR__.'/hhvm_config_check.php',
        })->map($x ==> escapeshellarg($x)),
     );
@@ -103,6 +106,10 @@ protected function getArguments(): Vector<string> {
       '-c',
       OSS_PERFORMANCE_ROOT.'/conf/php.ini',
     };
+
+    if ($this->options->runAsRoot) {
+      $args->addAll(Vector {'-v', 'Server.AllowRunAsRoot=1'});
+    }
     if ($this->options->jit) {
       $args->addAll(Vector {'-v', 'Eval.Jit=1'});
     } else {

base/MemcachedDaemon.php

@@ -59,17 +59,18 @@ protected function getArguments(): Vector<string> {
     if ($this->options->cpuBind) {
       $this->cpuRange = $this->options->helperProcessors;
     }
+    $processUser = posix_getpwuid(posix_geteuid());
     return Vector {
       '-m',
       (string) $this->maxMemory,
-      '-l',
-      '127.0.0.1',
       '-t',
       (string) $this->getNumThreads(),
       '-p',
       (string) $this->options->memcachedPort,
       '-P', # pid file
-      $this->getPidFilePath()
+      $this->getPidFilePath(),
+      '-u',
+      $processUser['name'],
     };
   }
 }

base/NginxDaemon.php

@@ -128,20 +128,49 @@ protected function getArguments(): Vector<string> {
   protected function getGeneratedConfigFile(): string {
     $path = $this->options->tempDir.'/nginx.conf';
 
+    $nameservers = self::GetNameServers();
+    $nginx_resolver_servers = [];
+    foreach ($nameservers as $nameserver) {
+      if (strpos($nameserver, ':')) {
+        // IPv6
+        $nginx_resolver_servers[] = '['.$nameserver.']';
+      } else if (strpos($nameserver, '.')) {
+        // IPv4
+        $nginx_resolver_servers[] = $nameserver;
+      }
+    }
+    $nginx_resolver_line = $nginx_resolver_servers
+      ? 'resolver '.implode(" ", $nginx_resolver_servers).';'
+      : '';
+
+
+    if ($nginx_resolver_line) {
+      $hostname = 'localhost';
+    } else {
+      # Could not find resolver, assuming IPv4 (default behavior)
+      $hostname = '127.0.0.1';
+    }
+
     if ($this->options->proxygen) {
       $proxy_pass = sprintf(
-        'proxy_pass http://127.0.0.1:%d$request_uri',
+        'proxy_pass http://%s:%d$request_uri',
+        $hostname,
         PerfSettings::BackendPort(),
       );
       $admin_proxy_pass = sprintf(
-        'proxy_pass http://127.0.0.1:%d$request_uri',
+        'proxy_pass http://%s:%d$request_uri',
+        $hostname,
         PerfSettings::BackendAdminPort(),
       );
     } else {
-      $proxy_pass =
-        sprintf('fastcgi_pass 127.0.0.1:%d', PerfSettings::BackendPort());
+      $proxy_pass = sprintf(
+        'fastcgi_pass %s:%d',
+        $hostname,
+        PerfSettings::BackendPort()
+      );
       $admin_proxy_pass = sprintf(
-        'fastcgi_pass 127.0.0.1:%d',
+        'fastcgi_pass %s:%d',
+        $hostname,
         PerfSettings::BackendAdminPort(),
       );
     }
@@ -161,6 +190,7 @@ protected function getGeneratedConfigFile(): string {
       '__FRAMEWORK_ROOT__' => $this->target->getSourceRoot(),
       '__NGINX_PID_FILE__' => $this->getPidFilePath(),
       '__DATE__' => date(DATE_W3C),
+      '__NGINX_RESOLVER__' => $nginx_resolver_line,
     };
 
     $config =
@@ -173,6 +203,19 @@ protected function getGeneratedConfigFile(): string {
     return $path;
   }
 
+  private static function GetNameServers(): Vector<string> {
+    $config = file('/etc/resolv.conf');
+    $matches = [];
+    $nameservers = Vector{};
+    foreach ($config as $line) {
+      $match = preg_match("/nameserver\s+(\S+)/", $line, &$matches);
+      if ($match) {
+        $nameservers[] = $matches[1];
+      }
+    }
+    return $nameservers;
+  }
+
   private static function GetPercentiles(
     Vector<float> $times,
   ): Map<string, float> {

base/PerfOptions.php

@@ -55,6 +55,7 @@ final class PerfOptions {
   public bool $dumpIsCompressed = true;
   public bool $traceSubProcess = false;
   public bool $noTimeLimit = false;
+  public bool $runAsRoot = false;
 
   // Pause once benchmarking is complete to allow for manual inspection of the
   // HHVM or PHP process.
@@ -174,6 +175,7 @@ public function __construct(Vector<string> $argv) {
       'php-extra-arguments:',
       'php-fcgi-children:',
       'no-time-limit',
+      'run-as-root',
       'fetch-resources',
       'skip-sanity-check',
       'skip-warmup',
@@ -284,6 +286,7 @@ public function __construct(Vector<string> $argv) {
     $this->skipVersionChecks = $this->getBool('skip-version-checks');
     $this->skipDatabaseInstall = $this->getBool('skip-database-install');
     $this->noTimeLimit = $this->getBool('no-time-limit');
+    $this->runAsRoot = $this->getBool('run-as-root');
     $this->waitAtEnd = $this->getBool('wait-at-end');
     $this->proxygen = !$this->getBool('no-proxygen');
     $this->statCache = $this->getBool('stat-cache');

base/SystemChecks.php

@@ -10,15 +10,26 @@
 
 class SystemChecks {
   public static function CheckAll(PerfOptions $options): void {
-    self::CheckNotRoot();
+    self::CheckNotRoot($options);
     self::CheckPortAvailability($options);
     self::CheckCPUFreq();
     self::CheckTCPTimeWaitReuse();
     self::CheckForAuditd($options);
   }
 
-  private static function CheckNotRoot(): void {
-    invariant(getmyuid() !== 0, 'Run this script as a regular user.');
+  private static function CheckNotRoot(PerfOptions $options): void {
+    if ($options->runAsRoot) {
+      fprintf(
+          STDERR,
+          "WARNING: Running as root. This is dangerous.\n"
+        );
+    } else {
+      invariant(
+        getmyuid() !== 0,
+        'Run this script as a regular user. Alternatively, '.
+        'pass the --run-as-root --i-am-not-benchmarking to continue anway.'
+      );
+    }
   }
 
   private static function CheckForAuditd(PerfOptions $options): void {

conf/nginx/nginx.conf.in

@@ -33,6 +33,8 @@ http {
 
   #gzip  on;
 
+  __NGINX_RESOLVER__
+
   server {
     listen [::]:__HTTP_PORT__ default_server;
     listen __HTTP_PORT__ default_server;