Add --observatory-host switch

common/settings.cc

@@ -42,8 +42,8 @@ std::string Settings::ToString() const {
   stream << "enable_dart_profiling: " << enable_dart_profiling << std::endl;
   stream << "disable_dart_asserts: " << disable_dart_asserts << std::endl;
   stream << "enable_observatory: " << enable_observatory << std::endl;
+  stream << "observatory_host: " << observatory_host << std::endl;
   stream << "observatory_port: " << observatory_port << std::endl;
-  stream << "ipv6: " << ipv6 << std::endl;
   stream << "use_test_fonts: " << use_test_fonts << std::endl;
   stream << "enable_software_rendering: " << enable_software_rendering
          << std::endl;

common/settings.h

@@ -101,11 +101,17 @@ struct Settings {
   std::string advisory_script_entrypoint = "main";
 
   // Observatory settings
+
+  // Whether the Dart VM service should be enabled.
   bool enable_observatory = false;
-  // Port on target will be auto selected by the OS. A message will be printed
-  // on the target with the port after it has been selected.
+
+  // The IP address to which the Dart VM service is bound.
+  std::string observatory_host;
+
+  // The port to which the Dart VM service is bound. When set to `0`, a free
+  // port will be automatically selected by the OS. A message is logged on the
+  // target indicating the URL at which the VM service can be accessed.
   uint32_t observatory_port = 0;
-  bool ipv6 = false;
 
   // Determines whether an authentication code is required to communicate with
   // the VM service.

runtime/dart_isolate.cc

@@ -613,9 +613,9 @@ Dart_Isolate DartIsolate::DartCreateAndStartServiceIsolate(
 
   tonic::DartState::Scope scope(service_isolate);
   if (!DartServiceIsolate::Startup(
-          settings.ipv6 ? "::1" : "127.0.0.1",  // server IP address
-          settings.observatory_port,            // server observatory port
-          tonic::DartState::HandleLibraryTag,   // embedder library tag handler
+          settings.observatory_host,           // server IP address
+          settings.observatory_port,           // server observatory port
+          tonic::DartState::HandleLibraryTag,  // embedder library tag handler
           false,  //  disable websocket origin check
           settings.disable_service_auth_codes,  // disable VM service auth codes
           error                                 // error (out)

shell/common/switches.cc

@@ -188,6 +188,18 @@ Settings SettingsFromCommandLine(const fml::CommandLine& command_line) {
   settings.enable_observatory =
       !command_line.HasOption(FlagForSwitch(Switch::DisableObservatory));
 
+  // Set Observatory Host
+  if (command_line.HasOption(FlagForSwitch(Switch::DeviceObservatoryHost))) {
+    command_line.GetOptionValue(FlagForSwitch(Switch::DeviceObservatoryHost),
+                                &settings.observatory_host);
+  }
+  // Default the observatory port based on --ipv6 if not set.
+  if (settings.observatory_host.empty()) {
+    settings.observatory_host =
+        command_line.HasOption(FlagForSwitch(Switch::IPv6)) ? "::1"
+                                                            : "127.0.0.1";
+  }
+
   // Set Observatory Port
   if (command_line.HasOption(FlagForSwitch(Switch::DeviceObservatoryPort))) {
     if (!GetSwitchValue(command_line, Switch::DeviceObservatoryPort,
@@ -207,8 +219,6 @@ Settings SettingsFromCommandLine(const fml::CommandLine& command_line) {
   settings.disable_dart_asserts =
       command_line.HasOption(FlagForSwitch(Switch::DisableDartAsserts));
 
-  settings.ipv6 = command_line.HasOption(FlagForSwitch(Switch::IPv6));
-
   settings.start_paused =
       command_line.HasOption(FlagForSwitch(Switch::StartPaused));
 

shell/common/switches.h

@@ -61,6 +61,11 @@ DEF_SWITCH(DartFlags,
            "dart-flags",
            "Flags passed directly to the Dart VM without being interpreted "
            "by the Flutter shell.")
+DEF_SWITCH(DeviceObservatoryHost,
+           "observatory-host",
+           "The hostname/IP address on which the Dart Observatory should "
+           "be served. If not set, defaults to 127.0.0.1 or ::1 depending on "
+           "whether --ipv6 is specified.")
 DEF_SWITCH(DeviceObservatoryPort,
            "observatory-port",
            "A custom Dart Observatory port. The default is to pick a randomly "
@@ -71,7 +76,8 @@ DEF_SWITCH(DisableObservatory,
            "in release mode.")
 DEF_SWITCH(IPv6,
            "ipv6",
-           "Bind to the IPv6 localhost address for the Dart Observatory.")
+           "Bind to the IPv6 localhost address for the Dart Observatory. "
+           "Ignored if --observatory-host is set.")
 DEF_SWITCH(EnableDartProfiling,
            "enable-dart-profiling",
            "Enable Dart profiling. Profiling information can be viewed from "