checking if XenServerVssProvider service exists before restart

src/Rackspace.Cloud.Server.Agent/Commands/XentoolsUpdate.cs

@@ -14,7 +14,9 @@
 // under the License.
 
 using System;
-using System.Collections.Generic;
+using System.Collections.Generic;
+using System.Linq;
+using System.ServiceProcess;
 using Rackspace.Cloud.Server.Agent.Actions;
 using Rackspace.Cloud.Server.Agent.Configuration;
 using Rackspace.Cloud.Server.Agent.Interfaces;
@@ -67,8 +69,9 @@ public ExecutableResult Execute(string value)
  {Constants.XenToolsSetupExecutablePath,
  String.Format("/S /norestart /D={0}", Constants.XenToolsPath)}
  });
- _serviceRestarter.Restart("xensvc");
- _serviceRestarter.Restart("XenServerVssProvider");
+ _serviceRestarter.Restart("xensvc");
+ if (DoesServiceExist("XenServerVssProvider"))
+ _serviceRestarter.Restart("XenServerVssProvider");
  Statics.ShouldPollXenStore = true;
  return new ExecutableResult();
  }
@@ -82,7 +85,13 @@ public ExecutableResult Execute(string value)
  {
  _finalizer.Finalize(new List<string>{Constants.XenToolsUnzipPath,Constants.XenToolsReleasePackage});
  }
+ }
+
+ public static bool DoesServiceExist(string serviceName)
+ {
+ var services = ServiceController.GetServices();
+ var service = services.FirstOrDefault(s => s.ServiceName.Equals(serviceName, StringComparison.InvariantCultureIgnoreCase));
+ return service != null;
  }
-
  }
 }