Added Pending Windows Update check

lib/plugins/Invoke-IcingaCheckUpdates.psm1

@@ -0,0 +1,54 @@
+Import-IcingaLib icinga\plugin;
+Import-IcingaLib provider\updates;
+
+function Invoke-IcingaCheckUpdates()
+{
+    param (
+        [array]$UpdateFilter,
+        $Warning,
+        $Critical,
+        [switch]$NoPerfData,
+        [int]$Verbose
+    );
+
+    $PendingUpdates = Get-IcingaUpdatesPending;
+    
+    $UpdateCount    = New-IcingaCheckPackage -Name 'Pending Update Count' -OperatorAnd;
+    $UpdateList     = New-IcingaCheckPackage -Name 'Update List' -OperatorAnd;
+    $PendingCount   = 0;
+
+    if ($UpdateFilter.Count -ne 0) {
+        foreach ($Filter in $UpdateFilter) {
+            foreach ($Update in $PendingUpdates.updates.Keys) {
+                if ($Update -Like $Filter) {
+                    $PendingCount += 1;
+                    $UpdateList.AddCheck(
+                        (New-IcingaCheck -Name $Update -Value 'pending' -NoPerfData)
+                    );
+                }
+            }
+        }
+        if ($PendingCount -eq 0) {
+            $UpdateList.AddCheck(
+                (New-IcingaCheck -Name 'No update' -Value 'pending' -NoPerfData)
+            );
+        }
+    } else {
+        $PendingCount = $PendingUpdates.count;
+        foreach ($Update in $PendingUpdates.updates.Keys) {
+            $UpdateList.AddCheck(
+                (New-IcingaCheck -Name $Update -Value 'pending' -NoPerfData)
+            );
+        }
+    }
+
+    $IcingaCheck = New-IcingaCheck -Name 'Pending Update Count' -Value $PendingCount;
+    $IcingaCheck.WarnOutOfRange($Warning).CritOutOfRange($Critical) | Out-Null;
+    $UpdateCount.AddCheck($IcingaCheck);
+
+    $UpdatePackage  = New-IcingaCheckPackage -Name 'Updates' -OperatorAnd -Verbose $Verbose -Checks @(
+        $UpdateCount, $UpdateList
+    );
+
+    exit (New-IcingaCheckResult -Name 'Pending Updates' -Check $UpdatePackage -NoPerfData $NoPerfData -Compile);
+}