Question

OK, I can’t fully decide if this is better asked on ServerFault or SO, but I think this is more of a programming question at heart…(you may disagree)

I’m trying to wrap up all sorts of deployment activities into a single console application, then execute it with appropriate parameters with the TeamCity build Command Line runner. However, attempting to stop/start/install Windows services on a remote machine seems to be a tricky business using ServiceController from a process that can’t run with elevated permissions.

At this point, it might actually be the easiest method to execute Powershell scripts using Invoke-Command on each remote host. (of course, allowing this is a different security hole) than disabling UAC or other options…

Would anyone care to venture an opinion of what methodology would be the best way to proceed?

Answer 1

OK, I created a Powershell-based service controller class to allow an application running without elevated permissions to control remote services.

Here it is:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
//
using System.Collections.ObjectModel;
using System.Management.Automation;
using System.Management.Automation.Runspaces;

namespace PowershellBasedServiceControl
{
    // All the relevant bits came from this article: http://www.codeproject.com/KB/cs/HowToRunPowerShell.aspx
    // if script execution fails, try running 'Enable-PSRemoting' using Powershell as an admin on the target host

public class PowershellServiceController
{
    public bool StartService(string serviceName, string remoteHost)
    {
        return StartService(serviceName, remoteHost, String.Empty, String.Empty);
    }

    public bool StartService(string serviceName, string remoteHost, string remoteUserName, string remotePassword)
    {
        bool result = false;
        string execOutput = ExecuteScript(BuildStartServiceScript(serviceName, remoteHost, remoteUserName, remotePassword, false));
        result = execOutput.StartsWith("0");
        if (!result)
            Console.WriteLine(execOutput);
        return result;
    }

    public bool StopService(string serviceName, string remoteHost)
    {
        return StopService(serviceName, remoteHost, String.Empty, String.Empty);
    }

    public bool StopService(string serviceName, string remoteHost, string remoteUserName, string remotePassword)
    {
        bool result = false;
        string execOutput = ExecuteScript(BuildStopServiceScript(serviceName, remoteHost, remoteUserName, remotePassword, false));
        result = execOutput.StartsWith("0");
        if (!result)
            Console.WriteLine(execOutput);
        return result;
    }

    string ExecuteScript(string scriptText)
    {
        Runspace runspace = RunspaceFactory.CreateRunspace();
        runspace.Open();
        // create a pipeline and feed it the script text
        Pipeline pipeline = runspace.CreatePipeline();
        pipeline.Commands.AddScript(scriptText);
        // add an extra command to transform the script
        // output objects into nicely formatted strings
        // remove this line to get the actual objects
        // that the script returns. For example, the script
        // "Get-Process" returns a collection
        // of System.Diagnostics.Process instances.
        pipeline.Commands.Add("Out-String");
        // execute the script
        Collection<PSObject> results = pipeline.Invoke();
        // close the runspace
        runspace.Close();
        // convert the script result into a single string
        StringBuilder stringBuilder = new StringBuilder();
        foreach (PSObject obj in results)
        {
            stringBuilder.AppendLine(obj.ToString());
        }
        return stringBuilder.ToString();
    }

    string BuildStartServiceScript(string serviceName, string remoteHost, string remoteUserName, string remotePassword, bool echoScript)
    {
        StringBuilder script = new StringBuilder();
        if (!String.IsNullOrEmpty(remoteUserName))
        {
            script.AppendLine("$block = {");
            script.AppendLine("$returnCode = 1");
            script.AppendLine("try {");
            script.AppendLine(String.Format("$service = \"{0}\"", serviceName));
            script.AppendLine("$serviceController = (new-Object System.ServiceProcess.ServiceController($service,\"localhost\"))");
            script.AppendLine("if($serviceController.Status -notlike 'Running') {");
            script.AppendLine("$serviceController.Start()");
            script.AppendLine("$serviceController.WaitForStatus('Running',(new-timespan -seconds 120))");
            script.AppendLine("if ($serviceController.Status -eq 'Running') { ");
            script.AppendLine("$returnCode = 0 }");
            script.AppendLine("} else { ");
            script.AppendLine("$returnCode = 0 } }");
            script.AppendLine("catch {");
            script.AppendLine("return 1");
            script.AppendLine("exit }");
            script.AppendLine("return $returnCode}");
            script.AppendLine("");

            script.AppendLine(String.Format("$pass = convertto-securestring \"{0}\" -asplaintext -force", remotePassword));
            script.AppendLine(String.Format("$mycred = new-object -typename System.Management.Automation.PSCredential -argumentlist \"{0}\",$pass", remoteUserName));

            script.AppendLine(String.Format("$res = Invoke-Command -computername \"{0}\" -Credential $mycred -scriptblock $block", remoteHost));
            script.AppendLine("return $res");
        }
        if (echoScript)
            Console.WriteLine(script.ToString());
        return script.ToString();
    }

    string BuildStopServiceScript(string serviceName, string remoteHost, string remoteUserName, string remotePassword, bool echoScript)
    {
        StringBuilder script = new StringBuilder();
        if (!String.IsNullOrEmpty(remoteUserName))
        {
            script.AppendLine("$block = {");
            script.AppendLine("$returnCode = 1");
            script.AppendLine("try {");
            script.AppendLine(String.Format("$service = \"{0}\"", serviceName));
            script.AppendLine("$serviceController = (new-Object System.ServiceProcess.ServiceController($service,\"localhost\"))");
            script.AppendLine("if($serviceController.Status -notlike 'Stopped') {");
            script.AppendLine("$serviceController.Stop()");
            script.AppendLine("$serviceController.WaitForStatus('Stopped',(new-timespan -seconds 120))");
            script.AppendLine("if ($serviceController.Status -eq 'Stopped') { ");
            script.AppendLine("$returnCode = 0 }");
            script.AppendLine("} else { ");
            script.AppendLine("$returnCode = 0 } }");
            script.AppendLine("catch {");
            script.AppendLine("return 1");
            script.AppendLine("exit }");
            script.AppendLine("return $returnCode}");
            script.AppendLine("");

            script.AppendLine(String.Format("$pass = convertto-securestring \"{0}\" -asplaintext -force", remotePassword));
            script.AppendLine(String.Format("$mycred = new-object -typename System.Management.Automation.PSCredential -argumentlist \"{0}\",$pass", remoteUserName));

            script.AppendLine(String.Format("$res = Invoke-Command -computername \"{0}\" -Credential $mycred -scriptblock $block", remoteHost));
            script.AppendLine("return $res");
        }
        if (echoScript)
            Console.WriteLine(script.ToString());
        return script.ToString();
    }
}

}

Here’s how you would use it in a console app:

class Program
{
    static void Main(string[] args)
    {
        PowershellServiceController runner = new PowershellServiceController();
        if (runner.StartService("w3svc", "myremotehost.com", "myusername", "mypassword"))
            Console.WriteLine("Service was started successfully");
        else
            Console.WriteLine("Failed to start remote service");
        Console.WriteLine("Press ENTER to quit");
        Console.ReadLine();
    }
}

Hopefully someone else finds this useful.