From 5a064078b2d6d58e738745f0e4f2d9d574828e83 Mon Sep 17 00:00:00 2001
From: Lord Hepipud <contact@lordhepipud.de>
Date: Wed, 29 Jul 2020 11:03:19 +0200
Subject: [PATCH] Adds new Cmdlet Show-IcingaPerformanceCounterInstances

---
 doc/31-Changelog.md                           |  4 ++
 ...how-IcingaPerformanceCounterInstances.psm1 | 58 +++++++++++++++++++
 2 files changed, 62 insertions(+)
 create mode 100644 lib/core/perfcounter/Show-IcingaPerformanceCounterInstances.psm1

diff --git a/doc/31-Changelog.md b/doc/31-Changelog.md
index 9b32a6e..abec908 100644
--- a/doc/31-Changelog.md
+++ b/doc/31-Changelog.md
@@ -15,6 +15,10 @@ Released closed milestones can be found on [GitHub](https://github.com/Icinga/ic
 
 * [#80](https://github.com/Icinga/icinga-powershell-framework/issues/80) Adds wrapper function `Get-IcingaWindowsInformation` for WMI and CIM calls to properly handle config/permission errors
 
+### Enhancements
+
+* Adds new Cmdlet `Show-IcingaPerformanceCounterInstances` to display all avaiable instances for Performance Counters
+
 ### Bugfixes
 
 * [#78](https://github.com/Icinga/icinga-powershell-framework/issues/78) Fix Icinga Agent package fetching for x86 architecture
diff --git a/lib/core/perfcounter/Show-IcingaPerformanceCounterInstances.psm1 b/lib/core/perfcounter/Show-IcingaPerformanceCounterInstances.psm1
new file mode 100644
index 0000000..7bb9aba
--- /dev/null
+++ b/lib/core/perfcounter/Show-IcingaPerformanceCounterInstances.psm1
@@ -0,0 +1,58 @@
+<#
+.SYNOPSIS
+   Displays all available instances for a provided Performance Counter
+.DESCRIPTION
+   Displays all available instances for a provided Performance Counter
+.FUNCTIONALITY
+   Displays all available instances for a provided Performance Counter
+.PARAMETER Counter
+   The name of the Performance Counter to fetch data for
+.EXAMPLE
+   PS>Show-IcingaPerformanceCounterInstances -Counter '\Processor(*)\% processor time';
+
+   Name                           Value
+    ----                           -----
+    _Total                         \Processor(_Total)\% processor time
+    0                              \Processor(0)\% processor time
+    1                              \Processor(1)\% processor time
+    2                              \Processor(2)\% processor time
+    3                              \Processor(3)\% processor time
+    ...
+.LINK
+   https://github.com/Icinga/icinga-powershell-framework
+#>
+
+function Show-IcingaPerformanceCounterInstances()
+{
+    param (
+        [string]$Counter
+    );
+
+    [hashtable]$Instances = @{};
+
+    if ([string]::IsNullOrEmpty($Counter)) {
+        Write-IcingaConsoleError 'Please enter a Performance Counter';
+        return;
+    }
+
+    $PerfCounter  = New-IcingaPerformanceCounter -Counter $Counter -SkipWait $TRUE;
+
+    foreach ($entry in $PerfCounter.Counters) {
+        $Instances.Add(
+            $entry.Instance,
+            ($Counter.Replace('(*)', ([string]::Format('({0})', $entry.Instance))))
+        );
+    }
+
+    if ($Instances.Count -eq 0) {
+        Write-IcingaConsoleNotice `
+            -Message 'No instances were found for Performance Counter "{0}". Please ensure the provided counter has instances and you are using "*" for the instance name.' `
+            -Objects $Counter;
+
+        return;
+    }
+
+    return (
+        $Instances.GetEnumerator() | Sort-Object Name
+    );
+}