Fixes exceptions in certain cases while trying to stop the JEA process

Author: LordHepipud

doc/100-General/10-Changelog.md

@@ -14,6 +14,7 @@ Released closed milestones can be found on [GitHub](https://github.com/Icinga/ic
 ### Bugfixes
 
 * [#683](https://github.com/Icinga/icinga-powershell-framework/pull/683) Fixes JEA installer to exclude domain from user name length check, which can easily exceed the Windows 20 digits username limit
+* [#685](https://github.com/Icinga/icinga-powershell-framework/pull/685) Fixes an issue while trying to stop the JEA process in certain cases, which results in an error during installation but has no other effect on the environment
 * [#686](https://github.com/Icinga/icinga-powershell-framework/pull/686) Fixes certutil error handling and message output in case the icingaforwindows.pfx could not be created
 
 ### Enhancements

lib/core/jea/Get-IcingaJEAServicePid.psm1

@@ -7,5 +7,9 @@ function Get-IcingaJEAServicePid()
         $JeaPid = $JeaPid.Replace("`r`n", '').Replace("`n", '').Replace(' ', '');
     }
 
+    if ([string]::IsNullOrEmpty($JeaPid) -Or $JeaPid -eq '0' -Or $JeaPid -eq 0) {
+        return $null;
+    }
+
     return $JeaPid;
 }

lib/core/windows/Restart-IcingaWindowsService.psm1

@@ -5,7 +5,7 @@ function Restart-IcingaWindowsService()
     Stop-IcingaService -Service 'icingapowershell';
 
     if ((Test-IcingaJEAServiceRunning -JeaPid $JeaPid)) {
-        Stop-Process -Id $JeaPid -Force;
+        Stop-IcingaJEAProcess -JeaPid $JeaPid;
     }
 
     Restart-IcingaService -Service 'icingapowershell';

lib/core/windows/Stop-IcingaJEAProcess.psm1

@@ -0,0 +1,33 @@
+function Stop-IcingaJEAProcess()
+{
+    param (
+        [string]$JeaPid = $null
+    );
+
+    if ([string]::IsNullOrEmpty($JeaPid)) {
+        [string]$JeaPid = Get-IcingaJEAServicePid;
+    }
+
+    if ([string]::IsNullOrEmpty($JeaPid)) {
+        return;
+    }
+
+    if ($JeaPid -eq '0' -Or $JeaPid -eq 0) {
+        return;
+    }
+
+    $JeaPowerShellProcess = Get-Process -Id $JeaPid -ErrorAction SilentlyContinue;
+    if ($null -eq $JeaPowerShellProcess) {
+        return;
+    }
+
+    if ($JeaPowerShellProcess.ProcessName -ne 'wsmprovhost') {
+        return;
+    }
+
+    try {
+        Stop-Process -Id $JeaPid -Force -ErrorAction Stop;
+    } catch {
+        Write-IcingaConsoleError 'Unable to stop the JEA process "wsmprovhost" caused by the following error: "{0}".' -Objects $_.Exception.Message;
+    }
+}