[VM Service] Add service info file dumping and bind address support

Adds support for writing the active VM service connection URI to the file
specified by `--write-service-info-to-file` and updates native bindings
with the web server address on startups.

TAG=agy
CONV=ae3a29f5-e2c8-499c-b221-ff61e40f5f1f

Change-Id: Ice85fda098031ef4ba1cd1120a917137aae97105
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/505163
Auto-Submit: Ben Konyi <bkonyi@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>

pkg/dart_runtime_service/lib/src/dart_runtime_service.dart

@@ -240,9 +240,15 @@ class DartRuntimeService {
         throw const DartRuntimeServiceServerAlreadyRunning();
       }
       final hostStr = config.host ?? InternetAddress.loopbackIPv4.host;
-      final host =
-          InternetAddress.tryParse(hostStr) ??
-          (await InternetAddress.lookup(hostStr)).first;
+      var parsedHost = InternetAddress.tryParse(hostStr);
+      if (parsedHost == null) {
+        final addresses = await InternetAddress.lookup(hostStr);
+        parsedHost = addresses.firstWhere(
+          (a) => a.type == InternetAddressType.IPv4,
+          orElse: () => addresses.first,
+        );
+      }
+      final host = parsedHost;
 
       _logger.info('Starting the Dart Runtime Service.');
       late String errorMessage;

pkg/dart_runtime_service_vm/lib/dart_runtime_service_vm.dart

@@ -35,6 +35,7 @@ class DartRuntimeServiceVMBackend
     required Stream<VmRunningIsolate> runningIsolatesStream,
     required this.residentCompilerInfoFile,
     required this._ddsManager,
+    this.serviceInfoFilename,
   }) : isolateManager = VmIsolateManager(
          runningIsolatesStream: runningIsolatesStream,
        );
@@ -89,6 +90,9 @@ class DartRuntimeServiceVMBackend
   /// Dart Development Service.
   final DartDevelopmentServiceManager _ddsManager;
 
+  /// The path to the file where VM service connection info should be written.
+  final String? serviceInfoFilename;
+
   @override
   UnmodifiableListView<ServiceRpcHandler> get rpcs => UnmodifiableListView([
     ..._vmServiceRpcs.rpcs,
@@ -181,6 +185,22 @@ class DartRuntimeServiceVMBackend
       );
     }
     _nativeBindings.onServerAddressChange(httpUri.toString());
+
+    final serviceInfoFilenameLocal = serviceInfoFilename;
+    if (serviceInfoFilenameLocal != null &&
+        serviceInfoFilenameLocal.isNotEmpty) {
+      await _dumpServiceInfoToFile(serviceInfoFilenameLocal, httpUri);
+    }
+  }
+
+  Future<void> _dumpServiceInfoToFile(String filename, Uri httpUri) async {
+    final serviceInfo = <String, String>{'uri': httpUri.toString()};
+    const kFileScheme = 'file://';
+    final uri = filename.startsWith(kFileScheme)
+        ? Uri.parse(filename)
+        : Uri.file(filename);
+    final file = File.fromUri(uri);
+    await file.writeAsString(json.encode(serviceInfo));
   }
 
   @override