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Power up Hyper_V client in C# using WMI

I am new to coding the Hyper-V within WMI, and always welcome to a learning opportunity in this area.
There is a need for me to create a winform application that lists all VMs available within a computer. When a user clicks on one VM, it will launch the Hyper-V client window.
My codes below could pretty much start or stop any specific VM. However, it doesn't launch the hyper-v client window.
Here are my prototype codes (in command lines for now):
using System;
using System.Management;
namespace HyperVSamples
{
public class RequestStateChangeClass
{
public static void RequestStateChange(string vmName, string action)
{
ManagementScope scope = new ManagementScope(#"\\.\root\virtualization\v2", null);
ManagementObject vm = Utility.GetTargetComputer(vmName, scope);
if (null == vm)
{
throw new ArgumentException(
string.Format(
"The virtual machine '{0}' could not be found.",
vmName));
}
ManagementBaseObject inParams = vm.GetMethodParameters("RequestStateChange");
const int Enabled = 2;
const int Disabled = 3;
if (action.ToLower() == "start")
{
inParams["RequestedState"] = Enabled;
}
else if (action.ToLower() == "stop")
{
inParams["RequestedState"] = Disabled;
}
else
{
throw new Exception("Wrong action is specified");
}
ManagementBaseObject outParams = vm.InvokeMethod(
"RequestStateChange",
inParams,
null);
if ((UInt32)outParams["ReturnValue"] == ReturnCode.Started)
{
if (Utility.JobCompleted(outParams, scope))
{
Console.WriteLine(
"{0} state was changed successfully.",
vmName);
}
else
{
Console.WriteLine("Failed to change virtual system state");
}
}
else if ((UInt32)outParams["ReturnValue"] == ReturnCode.Completed)
{
Console.WriteLine(
"{0} state was changed successfully.",
vmName);
}
else
{
Console.WriteLine(
"Change virtual system state failed with error {0}",
outParams["ReturnValue"]);
}
}
public static void Main(string[] args)
{
if (args != null && args.Length != 2)
{
Console.WriteLine("Usage: <application> vmName action");
Console.WriteLine("action: start|stop");
return;
}
RequestStateChange(args[0], args[1]);
}
}
}
Given:
The computer has Hyper-V manager installed with several pre-populated VMs.
Question:
How would I fire up the hyper-v client window from a winform?
Thanks

After taking some research, it appears firing up the hyper-v client is quite simple.... Below is the full function just in case anyone looks for it in the future...
public static string ConnectVM(string VMName)
{
var error = string.Empty;
var runspace = RunspaceFactory.CreateRunspace();
runspace.Open();
//create a pipeline
var path = ConfigurationManager.AppSettings["VMConnectPath"];
var pipeline = runspace.CreatePipeline();
pipeline.Commands.AddScript($"& \"{path}\" localhost '{VMName}'");
try
{
pipeline.Invoke();
}
catch (Exception e)
{
error = e.Message;
}
runspace.Close();
return error;
}

Prevent running multiple instances of a mono app

I know how to prevent running multiple instances of a given app on Windows:
Prevent multiple instances of a given app in .NET?
This code does not work under Linux using mono-develop though. It compiles and runs but it does not work. How can I prevent it under Linux using mono?
This is what I have tried but the code deos not work under linux only on windows.
static void Main()
{
Task.Factory.StartNew(() =>
{
try
{
var p = new NamedPipeServerStream("SomeGuid", PipeDirection.In, 1);
Console.WriteLine("Waiting for connection");
p.WaitForConnection();
}
catch
{
Console.WriteLine("Error another insance already running");
Environment.Exit(1); // terminate application
}
});
Thread.Sleep(1000);
Console.WriteLine("Doing work");
// Do work....
Thread.Sleep(10000);
}

I came up with this answer. Call this method passing it a unique ID
public static void PreventMultipleInstance(string applicationId)
{
// Under Windows this is:
// C:\Users\SomeUser\AppData\Local\Temp\
// Linux this is:
// /tmp/
var temporaryDirectory = Path.GetTempPath();
// Application ID (Make sure this guid is different accross your different applications!
var applicationGuid = applicationId + ".process-lock";
// file that will serve as our lock
var fileFulePath = Path.Combine(temporaryDirectory, applicationGuid);
try
{
// Prevents other processes from reading from or writing to this file
var _InstanceLock = new FileStream(fileFulePath, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.None);
_InstanceLock.Lock(0, 0);
MonoApp.Logger.LogToDisk(LogType.Notification, "04ZH-EQP0", "Aquired Lock", fileFulePath);
// todo investigate why we need a reference to file stream. Without this GC releases the lock!
System.Timers.Timer t = new System.Timers.Timer()
{
Interval = 500000,
Enabled = true,
};
t.Elapsed += (a, b) =>
{
try
{
_InstanceLock.Lock(0, 0);
}
catch
{
MonoApp.Logger.Log(LogType.Error, "AOI7-QMCT", "Unable to lock file");
}
};
t.Start();
}
catch
{
// Terminate application because another instance with this ID is running
Environment.Exit(102534);
}
}

Single instance dotnetcore cli app on linux

I am interested in how to inforce a single instance policy for dotnetcore console apps. To my surprise it seems like there isn't much out there on the topic. I found this one stacko, How to restrict a program to a single instance, but it doesnt seem to work for me on dotnetcore with ubuntu. Anyone here do this before?

Variation of #MusuNaji's solution at: How to restrict a program to a single instance
private static bool AlreadyRunning()
{
Process[] processes = Process.GetProcesses();
Process currentProc = Process.GetCurrentProcess();
logger.LogDebug("Current proccess: {0}", currentProc.ProcessName);
foreach (Process process in processes)
{
if (currentProc.ProcessName == process.ProcessName && currentProc.Id != process.Id)
{
logger.LogInformation("Another instance of this process is already running: {pid}", process.Id);
return true;
}
}
return false;
}

This is a little more difficult on .NET core than it should be, due to the problem of mutex checking on Linux/MacOS (as reported above). Also Theyouthis's solution isn't helpful as all .NET core apps are run via the CLI which has a process name of 'dotnet' which if you are running multiple .NET core apps on the same machine the duplicate instance check will trigger incorrectly.
A simple way to do this that is also multi-platform robust is to open a file for write when the application starts, and close it at the end. If the file fails to open it is due to another instance running concurrently and you can handle that in the try/catch. Using FileStream to open the file will also create it if it doesn't first exist.
try
{
lockFile = File.OpenWrite("SingleInstance.lck");
}
catch (Exception)
{
Console.WriteLine("ERROR - Server is already running. End that instance before re-running. Exiting in 5 seconds...");
System.Threading.Thread.Sleep(5000);
return;
}

Here is my implementation using Named pipes. It supports passing arguments from the second instance.
Note: I did not test on Linux or Mac but it should work in theory.
Usage
public static int Main(string[] args)
{
instanceManager = new SingleInstanceManager("8A3B7DE2-6AB4-4983-BBC0-DF985AB56703");
if (!instanceManager.Start())
{
return 0; // exit, if same app is running
}
instanceManager.SecondInstanceLaunched += InstanceManager_SecondInstanceLaunched;
// Initialize app. Below is an example in WPF.
app = new App();
app.InitializeComponent();
return app.Run();
}
private static void InstanceManager_SecondInstanceLaunched(object sender, SecondInstanceLaunchedEventArgs e)
{
app.Dispatcher.Invoke(() => new MainWindow().Show());
}
Your Copy-and-paste code
public class SingleInstanceManager
{
private readonly string applicationId;
public SingleInstanceManager(string applicationId)
{
this.applicationId = applicationId;
}
/// <summary>
/// Detect if this is the first instance. If it is, start a named pipe server to listen for subsequent instances. Otherwise, send <see cref="Environment.GetCommandLineArgs()"/> to the first instance.
/// </summary>
/// <returns>True if this is tthe first instance. Otherwise, false.</returns>
public bool Start()
{
using var client = new NamedPipeClientStream(applicationId);
try
{
client.Connect(0);
}
catch (TimeoutException)
{
Task.Run(() => StartListeningServer());
return true;
}
var args = Environment.GetCommandLineArgs();
using (var writer = new BinaryWriter(client, Encoding.UTF8))
{
writer.Write(args.Length);
for (int i = 0; i < args.Length; i++)
{
writer.Write(args[i]);
}
}
return false;
}
private void StartListeningServer()
{
var server = new NamedPipeServerStream(applicationId);
server.WaitForConnection();
using (var reader = new BinaryReader(server, Encoding.UTF8))
{
var argc = reader.ReadInt32();
var args = new string[argc];
for (int i = 0; i < argc; i++)
{
args[i] = reader.ReadString();
}
SecondInstanceLaunched?.Invoke(this, new SecondInstanceLaunchedEventArgs { Arguments = args });
}
StartListeningServer();
}
public event EventHandler<SecondInstanceLaunchedEventArgs> SecondInstanceLaunched;
}
public class SecondInstanceLaunchedEventArgs
{
public string[] Arguments { get; set; }
}
Unit test
[TestClass]
public class SingleInstanceManagerTests
{
[TestMethod]
public void SingleInstanceManagerTest()
{
var id = Guid.NewGuid().ToString();
var manager = new SingleInstanceManager(id);
string[] receivedArguments = null;
var correctArgCount = Environment.GetCommandLineArgs().Length;
manager.SecondInstanceLaunched += (sender, e) => receivedArguments = e.Arguments;
var instance1 = manager.Start();
Thread.Sleep(200);
var manager2 = new SingleInstanceManager(id);
Assert.IsFalse(manager2.Start());
Thread.Sleep(200);
Assert.IsTrue(instance1);
Assert.IsNotNull(receivedArguments);
Assert.AreEqual(correctArgCount, receivedArguments.Length);
var receivedArguments2 = receivedArguments;
var manager3 = new SingleInstanceManager(id);
Thread.Sleep(200);
Assert.IsFalse(manager3.Start());
Assert.AreNotSame(receivedArguments, receivedArguments2);
Assert.AreEqual(correctArgCount, receivedArguments.Length);
}
}

The downside of deandob's solution is that one can launch the application from another path. So you may prefer some static path or a tmp path for all users.
Here is my attempt:
//second instance launch guard
var tempPath = Environment.GetEnvironmentVariable("TEMP", EnvironmentVariableTarget.Machine)
??
Path.GetTempPath();
var lockPath = Path.Combine(tempPath, "SingleInstance.lock");
await using var lockFile = File.OpenWrite(lockPath);
here I'm trying to get TEMP system variable at the scope of machine (not the user TEMP) and if its empty - fallback to the user's temp folder on windows or shared /tmp on some linuxes.

C# SVN Pre Commit Hook, SharpSvn error

I have a C# console application that I use as an SVN Pre Commit Hook. The console app is started perfectly. However, as soon as I try to do a Write using SharpSvn, I get this error:
Commit failed (details follow):
Commit blocked by pre-commit hook (exit code -1066598274) with output:
Unhandled Exception: System.Runtime.InteropServices.SEHException: External
component has thrown an exception.
at svn_client_cat2(svn_stream_t* , SByte* , svn_opt_revision_t* ,
svn_opt_revision_t* , svn_client_ctx_t* , apr_pool_t* )
at SharpSvn.SvnClient.Write(SvnTarget target, Stream output, SvnWriteArgs args)
at SharpSvn.SvnClient.Write(SvnTarget target, Stream output)
at SvnPreCommitHook.Program.Main(String[] args)
I have tried to do the svn.Write command from my own machine, pointing to svn://svn-server instead of localhost - and that works fine. I guess it is something on the server. TortoiseSVN is installed, although I don't see any context menus...
My code looks like this:
private static EventLog _serviceEventLog;
static void Main(string[] args)
{
_serviceEventLog = new EventLog();
if (!System.Diagnostics.EventLog.SourceExists("Svn Hooks"))
{
System.Diagnostics.EventLog.CreateEventSource("Svn Hooks", "Svn Hooks");
}
_serviceEventLog.Source = "Svn Hooks";
_serviceEventLog.Log = "Svn Hooks";
SvnHookArguments ha;
if (!SvnHookArguments.ParseHookArguments(args, SvnHookType.PreCommit, false, out ha))
{
/*Console.Error.WriteLine("Invalid arguments");
Environment.Exit(1);*/
}
using (SvnLookClient cl = new SvnLookClient())
{
SvnChangeInfoEventArgs ci;
cl.GetChangeInfo(ha.LookOrigin, out ci);
if (!ci.LogMessage.Equals("Svn Hook Test"))
{
AllowCommit();
return;
}
var checkoutDir = #"C:\SvnTemp\" + DateTime.Now.Ticks.ToString();
foreach (SvnChangeItem i in ci.ChangedPaths)
{
var checkoutFilepath = checkoutDir + "\\" + Path.GetFileName(i.Path);
if (!Directory.Exists(checkoutDir))
{
Directory.CreateDirectory(checkoutDir);
}
using (SvnClient svn = new SvnClient())
{
using (StreamWriter sw = new StreamWriter(checkoutFilepath))
{
svn.Write(SvnTarget.FromString("svn://localhost/" + i.RepositoryPath), sw.BaseStream);
}
}
var fileContents = File.ReadAllText(checkoutFilepath);
if (fileContents.Contains("Martin Normark"))
{
RemoveTempDirectory(checkoutDir);
PreventCommit("Name is not allowed!");
}
}
RemoveTempDirectory(checkoutDir);
}
AllowCommit();
}

Maybe one of the following:
64bit vs 32 bit
vcredist missing on the server

Maybe you should first catch the thrown exception by using the HandleProcessCorruptedStateExceptionsAttribute:
[HandleProcessCorruptedStateExceptions]
static void Main() // main entry point
{
try
{
}
catch (Exception ex)
{
// Handle Exception here ...
}
}

Publishing a Wcf service using BasicHttpBinding for remote clients

I've created 3 projects:
WcfServer -- The default WCF Service Library project, unchanged.
WcfServerConsole -- Console Application:
static void Main(string[] args)
{
try
{
var baseAddress = "http://localhost:9000/WcfTest/";
Type contract = typeof(IService1);
Type implementation = typeof(Service1);
var address = baseAddress + implementation.Name;
var binding = new BasicHttpBinding();
var service = new ServiceHost(implementation, new Uri[] { new Uri(address) });
service.AddServiceEndpoint(contract, binding, address);
AddBehaviors(service);
service.Open();
Console.WriteLine("Server ready. Press ENTER to terminate.");
Console.ReadLine();
service.Close();
}
catch (Exception e)
{
Console.WriteLine(e.Message);
Console.ReadLine();
}
}
private static void AddBehaviors(ServiceHost service)
{
var smb = service.Description.Behaviors.Find<ServiceMetadataBehavior>();
if (smb == null)
{
smb = new ServiceMetadataBehavior();
service.Description.Behaviors.Add(smb);
}
smb.HttpGetEnabled = true;
var sdb = service.Description.Behaviors.Find<ServiceDebugBehavior>();
if (sdb == null)
{
sdb = new ServiceDebugBehavior();
service.Description.Behaviors.Add(sdb);
}
sdb.IncludeExceptionDetailInFaults = true;
}
WcfClientConsole -- Console Application:
static void Main(string[] args)
{
Thread.Sleep(1000);
var proxy = new Service1Client();
proxy.Open();
var response = proxy.GetData(42);
proxy.Close();
Console.WriteLine(response);
Console.ReadLine();
}
Everything works fine locally. When I run the server, I can see http://localhost:9000/WcfTest/Service1 in my browser, and communication works as expected (run server, run client, see "You entered: 42" in WcfClientConsole). Now I want to do this remotely. I change baseAddress to "http://0.0.0.0:9000/WcfTest/" and run the server on another machine (192.168.150.140). On that machine, in a browser I can open http://localhost:9000/WcfTest/Service1 and http://127.0.0.1:9000/WcfTest/Service1 and http://192.168.150.140:9000/WcfTest/Service1 no problems. On my machine, my browser can't connect to http://192.168.150.140:9000/WcfTest/Service1, nor can Add Service Reference, and changing proxy to new Service1Client("BasicHttpBinding_IService1", "http://192.168.150.140:9000/WcfTest/Service1"); also fails ("There was no endpoint listening at http://192.168.150.140:9000/WcfTest/Service1 that could accept the message.").
Am I going about this the wrong way?

Check your firewall. That's usually the top cause of this kind of issue.