dsccommunity · PlagueHO · Jul 22, 2018 · Jul 3, 2018 · Jul 3, 2018 · Jul 3, 2018
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -9,6 +9,9 @@
   - Moved strings to localization file.
 - Changed the scope from Global to Script in MSFT_ScheduledTask.Integration.Tests.ps1
 - Changed the scope from Global to Script ComputerManagementDsc.Common.Tests.ps1
+- ScheduledTask:
+  - Added support for event based triggers, implemented using the ScheduleType OnEvent
+    fixes [Issue #167](https://github.com/PowerShell/ComputerManagementDsc/issues/167)
 
 ## 5.1.0.0
 

diff --git a/Modules/ComputerManagementDsc/DSCResources/MSFT_ScheduledTask/MSFT_ScheduledTask.psm1 b/Modules/ComputerManagementDsc/DSCResources/MSFT_ScheduledTask/MSFT_ScheduledTask.psm1
@@ -201,6 +201,15 @@ $script:localizedData = Get-LocalizedData `
     .PARAMETER LogonType
         Specifies the security logon method that Task Scheduler uses to run the tasks that
         are associated with the principal. Not used in Get-TargetResource.
+
+    .PARAMETER EventSubscription
+        The event subscription in a string that can be parsed as valid XML. This parameter is only
+        valid in combination with the OnEvent Schedule Type. For the query schema please check:
+        https://docs.microsoft.com/en-us/windows/desktop/WES/queryschema-schema
+
+    .PARAMETER Delay
+        The time to wait after an event based trigger was triggered. This parameter is only
+        valid in combination with the OnEvent Schedule Type.
 #>
 function Get-TargetResource
 {
@@ -234,7 +243,7 @@ function Get-TargetResource
 
         [Parameter()]
         [System.String]
-        [ValidateSet('Once', 'Daily', 'Weekly', 'AtStartup', 'AtLogOn')]
+        [ValidateSet('Once', 'Daily', 'Weekly', 'AtStartup', 'AtLogOn', 'OnEvent')]
         $ScheduleType,
 
         [Parameter()]
@@ -376,7 +385,15 @@ function Get-TargetResource
         [Parameter()]
         [ValidateSet('Group', 'Interactive', 'InteractiveOrPassword', 'None', 'Password', 'S4U', 'ServiceAccount')]
         [System.String]
-        $LogonType
+        $LogonType,
+
+        [Parameter()]
+        [System.String]
+        $EventSubscription,
+
+        [Parameter()]
+        [System.String]
+        $Delay = '00:00:00'
     )
 
     $TaskPath = ConvertTo-NormalizedTaskPath -TaskPath $TaskPath
@@ -436,6 +453,12 @@ function Get-TargetResource
                 break
             }
 
+            'MSFT_TaskEventTrigger'
+            {
+                $returnScheduleType = 'OnEvent'
+                break
+            }
+
             default
             {
                 $returnScheduleType = ''
@@ -510,6 +533,8 @@ function Get-TargetResource
             RunOnlyIfNetworkAvailable       = $settings.RunOnlyIfNetworkAvailable
             RunLevel                        = [System.String] $task.Principal.RunLevel
             LogonType                       = [System.String] $task.Principal.LogonType
+            EventSubscription               = $trigger.Subscription
+            Delay                           = ConvertTo-TimeSpanStringFromScheduledTaskString -TimeSpan $trigger.Delay
         }
     }
 }
@@ -665,6 +690,15 @@ function Get-TargetResource
     .PARAMETER LogonType
         Specifies the security logon method that Task Scheduler uses to run the tasks that
         are associated with the principal.
+
+    .PARAMETER EventSubscription
+        The event subscription in a string that can be parsed as valid XML. This parameter is only
+        valid in combination with the OnEvent Schedule Type. For the query schema please check:
+        https://docs.microsoft.com/en-us/windows/desktop/WES/queryschema-schema
+
+    .PARAMETER Delay
+        The time to wait after an event based trigger was triggered. This parameter is only
+        valid in combination with the OnEvent Schedule Type.
 #>
 function Set-TargetResource
 {
@@ -697,7 +731,7 @@ function Set-TargetResource
 
         [Parameter()]
         [System.String]
-        [ValidateSet('Once', 'Daily', 'Weekly', 'AtStartup', 'AtLogOn')]
+        [ValidateSet('Once', 'Daily', 'Weekly', 'AtStartup', 'AtLogOn', 'OnEvent')]
         $ScheduleType,
 
         [Parameter()]
@@ -839,7 +873,15 @@ function Set-TargetResource
         [Parameter()]
         [ValidateSet('Group', 'Interactive', 'InteractiveOrPassword', 'None', 'Password', 'S4U', 'ServiceAccount')]
         [System.String]
-        $LogonType
+        $LogonType,
+
+        [Parameter()]
+        [System.String]
+        $EventSubscription,
+
+        [Parameter()]
+        [System.String]
+        $Delay = '00:00:00'
     )
 
     $TaskPath = ConvertTo-NormalizedTaskPath -TaskPath $TaskPath
@@ -902,6 +944,13 @@ function Set-TargetResource
                 -ArgumentName DaysOfWeek
         }
 
+        if ($ScheduleType -eq 'OnEvent' -and -not ([xml]$EventSubscription))
+        {
+            New-InvalidArgumentException `
+                -Message ($script:localizedData.OnEventSubscriptionError) `
+                -ArgumentName EventSubscription
+        }
+
         # Configure the action
         $actionParameters = @{
             Execute = $ActionExecutable
@@ -989,7 +1038,8 @@ function Set-TargetResource
         # Configure the trigger
         $triggerParameters = @{}
 
-        if ($RandomDelay -gt [System.TimeSpan]::FromSeconds(0))
+        # A random delay is not supported when the scheduleType is set to OnEvent
+        if ($RandomDelay -gt [System.TimeSpan]::FromSeconds(0) -and $ScheduleType -ne 'OnEvent')
         {
             $triggerParameters.Add('RandomDelay', $RandomDelay)
         }
@@ -1049,9 +1099,23 @@ function Set-TargetResource
 
                 break
             }
+
+            'OnEvent'
+            {
+                Write-Verbose -Message ($script:localizedData.ConfigureTaskEventTrigger -f $TaskName)
+
+                $cimTriggerClass = Get-CimClass -ClassName MSFT_TaskEventTrigger -Namespace Root/Microsoft/Windows/TaskScheduler:MSFT_TaskEventTrigger
+                $trigger = New-CimInstance -CimClass $cimTriggerClass -ClientOnly
+                $trigger.Enabled = $true
+                $trigger.Delay = [System.Xml.XmlConvert]::ToString([timespan]$Delay)
+                $trigger.Subscription = $EventSubscription
+            }
         }
 
-        $trigger = New-ScheduledTaskTrigger @triggerParameters -ErrorAction SilentlyContinue
+        if ($ScheduleType -ne 'OnEvent')
+        {
+            $trigger = New-ScheduledTaskTrigger @triggerParameters -ErrorAction SilentlyContinue
+        }
 
         if (-not $trigger)
         {
@@ -1390,6 +1454,15 @@ function Set-TargetResource
     .PARAMETER LogonType
         Specifies the security logon method that Task Scheduler uses to run the tasks that
         are associated with the principal.
+
+    .PARAMETER EventSubscription
+        The event subscription in a string that can be parsed as valid XML. This parameter is only
+        valid in combination with the OnEvent Schedule Type. For the query schema please check:
+        https://docs.microsoft.com/en-us/windows/desktop/WES/queryschema-schema
+
+    .PARAMETER Delay
+        The time to wait after an event based trigger was triggered. This parameter is only
+        valid in combination with the OnEvent Schedule Type.
 #>
 function Test-TargetResource
 {
@@ -1423,7 +1496,7 @@ function Test-TargetResource
 
         [Parameter()]
         [System.String]
-        [ValidateSet('Once', 'Daily', 'Weekly', 'AtStartup', 'AtLogOn')]
+        [ValidateSet('Once', 'Daily', 'Weekly', 'AtStartup', 'AtLogOn', 'OnEvent')]
         $ScheduleType,
 
         [Parameter()]
@@ -1565,7 +1638,15 @@ function Test-TargetResource
         [Parameter()]
         [ValidateSet('Group', 'Interactive', 'InteractiveOrPassword', 'None', 'Password', 'S4U', 'ServiceAccount')]
         [System.String]
-        $LogonType
+        $LogonType,
+
+        [Parameter()]
+        [System.String]
+        $EventSubscription,
+
+        [Parameter()]
+        [System.String]
+        $Delay = '00:00:00'
     )
 
     $TaskPath = ConvertTo-NormalizedTaskPath -TaskPath $TaskPath
@@ -1580,7 +1661,16 @@ function Test-TargetResource
 
     if ($PSBoundParameters.ContainsKey('RandomDelay'))
     {
-        $PSBoundParameters['RandomDelay'] = (ConvertTo-TimeSpanFromTimeSpanString -TimeSpanString $RandomDelay).ToString()
+        if ($ScheduleType -eq 'OnEvent')
+        {
+            # A random delay is not supported when the ScheduleType is set to OnEvent.
+            Write-Verbose -Message ($script:localizedData.IgnoreRandomDelayWithTriggerTypeOnEvent -f $TaskName)
+            $null = $PSBoundParameters.Remove('RandomDelay')
+        }
+        else
+        {
+            $PSBoundParameters['RandomDelay'] = (ConvertTo-TimeSpanFromTimeSpanString -TimeSpanString $RandomDelay).ToString()
+        }
     }
 
     if ($PSBoundParameters.ContainsKey('RepetitionDuration'))

diff --git a/Modules/ComputerManagementDsc/DSCResources/MSFT_ScheduledTask/MSFT_ScheduledTask.schema.mof b/Modules/ComputerManagementDsc/DSCResources/MSFT_ScheduledTask/MSFT_ScheduledTask.schema.mof
@@ -7,7 +7,7 @@ class MSFT_ScheduledTask : OMI_BaseResource
     [Write, Description("The path to the .exe for this task")] string ActionExecutable;
     [Write, Description("The arguments to pass the executable")] string ActionArguments;
     [Write, Description("The working path to specify for the executable")] string ActionWorkingPath;
-    [Write, Description("When should the task be executed"), ValueMap{"Once", "Daily", "Weekly", "AtStartup", "AtLogOn"}, Values{"Once", "Daily", "Weekly", "AtStartup", "AtLogOn"}] string ScheduleType;
+    [Write, Description("When should the task be executed"), ValueMap{"Once", "Daily", "Weekly", "AtStartup", "AtLogOn", "OnEvent"}, Values{"Once", "Daily", "Weekly", "AtStartup", "AtLogOn", "OnEvent"}] string ScheduleType;
     [Write, Description("How many units (minutes, hours, days) between each run of this task?")] String RepeatInterval;
     [Write, Description("The time of day this task should start at - defaults to 12:00 AM. Not valid for AtLogon and AtStartup tasks")] DateTime StartTime;
     [Write, Description("Present if the task should exist, Absent if it should be removed"), ValueMap{"Present","Absent"}, Values{"Present","Absent"}] string Ensure;
@@ -42,4 +42,6 @@ class MSFT_ScheduledTask : OMI_BaseResource
     [Write, Description("Indicates that Task Scheduler runs the task only when a network is available. Task Scheduler uses the NetworkID parameter and NetworkName parameter that you specify in this cmdlet to determine if the network is available.")] Boolean RunOnlyIfNetworkAvailable;
     [Write, Description("Specifies the level of user rights that Task Scheduler uses to run the tasks that are associated with the principal. Defaults to 'Limited'."), ValueMap{"Limited","Highest"}, Values{"Limited","Highest"}] String RunLevel;
     [Write, Description("Specifies the security logon method that Task Scheduler uses to run the tasks that are associated with the principal."), ValueMap{"Group","Interactive","InteractiveOrPassword","None","Password","S4U","ServiceAccount"}, Values{"Group","Interactive","InteractiveOrPassword","None","Password","S4U","ServiceAccount"}] String LogonType;
+    [Write, Description("Specifies the EventSubscription in XML. This can be easily generated using the Windows Eventlog Viewer. For the query schema please check: https://docs.microsoft.com/en-us/windows/desktop/WES/queryschema-schema. Can only be used in combination with ScheduleType OnEvent")] String EventSubscription;
+    [Write, Description("Specifies a delay to the start of the trigger. The delay is a static delay before the task is executed. Can only be used in combination with ScheduleType OnEvent")] String Delay;
 };
diff --git a/...mputerManagementDsc/DSCResources/MSFT_ScheduledTask/en-US/MSFT_ScheduledTask.strings.psd1 b/...mputerManagementDsc/DSCResources/MSFT_ScheduledTask/en-US/MSFT_ScheduledTask.strings.psd1
@@ -10,6 +10,7 @@ ConvertFrom-StringData @'
     DaysIntervalError = DaysInterval must be greater than zero (0) for Daily schedules. DaysInterval specified is '{0}'.
     WeeksIntervalError = WeeksInterval must be greater than zero (0) for Weekly schedules. WeeksInterval specified is '{0}'.
     WeekDayMissingError = At least one weekday must be selected for Weekly schedule.
+    OnEventSubscriptionError = No (valid) XML Event Subscription was provided. This is required when the scheduletype is OnEvent.
     TriggerCreationError = Error creating new scheduled task trigger.
     ConfigureTriggerRepetitionMessage = Configuring trigger repetition.
     RepetitionIntervalError = Repetition interval is set to '{0}' but repetition duration is '{1}'.
@@ -20,6 +21,8 @@ ConvertFrom-StringData @'
     CreateScheduledTaskPrincipalMessage = Creating scheduled task principal for account '{0}' using logon type '{1}'.
     RemovePreviousScheduledTaskMessage = Removing previous scheduled task '{0}' from '{1}'.
     CreateNewScheduledTaskMessage = Creating new scheduled task '{0}' in '{1}'.
+    ConfigureTaskEventTrigger = Setting up an event based trigger on task {0}.
+    IgnoreRandomDelayWithTriggerTypeOnEvent = The parameter RandomDelay in task {0} is ignored. A random delay is not supported when the trigger type is set to OnEvent.
     SetRepetitionTriggerMessage = Setting repetition trigger settings on task '{0}' in '{1}'.
     RegisterScheduledTaskMessage = Registering the scheduled task '{0}' in '{1}'.
     RetrieveScheduledTaskMessage = Retrieving the scheduled task '{0}' from '{1}'.

diff --git a/...ComputerManagementDsc/Examples/Resources/ScheduledTask/13-CreateScheduledTasksOnEvent.ps1 b/...ComputerManagementDsc/Examples/Resources/ScheduledTask/13-CreateScheduledTasksOnEvent.ps1
@@ -0,0 +1,33 @@
+<#
+    .EXAMPLE
+    This example creates a scheduled task called 'TriggerOnServiceFailures' in the folder
+    root folder. The task is delayed by exactly 30 seconds each time. The task will run when
+    an error event 7001 of source Service Control Manager is generated in the system log.
+    When a service crashes, it waits for 30 seconds and then starts a new PowerShell instance,
+    in which the file c:\temp\seeme.txt get's created with the value 'Worked!'
+#>
+Configuration Example
+{
+    param
+    (
+        [Parameter()]
+        [System.String[]]
+        $NodeName = 'localhost'
+    )
+
+    Import-DscResource -ModuleName ComputerManagementDsc
+
+    Node $NodeName
+    {
+        ScheduledTask ServiceEventManager 
+        {
+            TaskName = 'TriggerOnServiceFailures'
+            Ensure = 'Present'
+            ScheduleType = 'OnEvent'
+            ActionExecutable = 'C:\windows\system32\WindowsPowerShell\v1.0\powershell.exe'
+            ActionArguments = '-Command Set-Content -Path c:\temp\seeme.txt -Value ''Worked!'''
+            EventSubscription = '<QueryList><Query Id="0" Path="System"><Select Path="System">*[System[Provider[@Name=''Service Control Manager''] and (Level=2) and (EventID=7001)]]</Select></Query></QueryList>'
+            Delay = '00:00:30'
+        }
+    }
+}
diff --git a/Tests/Integration/MSFT_ScheduledTask.Config.ps1 b/Tests/Integration/MSFT_ScheduledTask.Config.ps1
@@ -168,6 +168,25 @@ Configuration ScheduledTaskExecuteAsAdd
     }
 }
 
+Configuration ScheduledTaskOnEventAdd
+{
+    Import-DscResource -ModuleName ComputerManagementDsc
+    node 'localhost'
+    {
+        ScheduledTask ScheduledTaskOnEventAdd
+        {
+            TaskName          = 'Test task OnEvent'
+            TaskPath          = '\ComputerManagementDsc\'
+            Ensure            = 'Present'
+            ScheduleType      = 'OnEvent'
+            ActionExecutable  = 'C:\windows\system32\WindowsPowerShell\v1.0\powershell.exe'
+            ActionArguments   = '-Command Set-Content -Path c:\temp\seeme.txt -Value ''Worked!'''
+            EventSubscription = '<QueryList><Query Id="0" Path="System"><Select Path="System">*[System[Provider[@Name=''Service Control Manager''] and (Level=2) and (EventID=7001)]]</Select></Query></QueryList>'
+            Delay             = '00:00:30'
+        }
+    }
+}
+
 Configuration ScheduledTaskOnceMod
 {
     Import-DscResource -ModuleName ComputerManagementDsc
@@ -294,6 +313,25 @@ Configuration ScheduledTaskExecuteAsMod
     }
 }
 
+Configuration ScheduledTaskOnEventMod
+{
+    Import-DscResource -ModuleName ComputerManagementDsc
+    node 'localhost'
+    {
+        ScheduledTask ScheduledTaskOnEventMod
+        {
+            TaskName          = 'Test task OnEvent'
+            TaskPath          = '\ComputerManagementDsc\'
+            Ensure            = 'Present'
+            ScheduleType      = 'OnEvent'
+            ActionExecutable  = 'C:\windows\system32\WindowsPowerShell\v1.0\powershell.exe'
+            ActionArguments   = '-Command Set-Content -Path c:\temp\seeme.txt -Value ''Worked!'''
+            EventSubscription = '<QueryList><Query Id="0" Path="System"><Select Path="System">*[System[Provider[@Name=''Service Control Manager''] and (Level=2) and (EventID=7002)]]</Select></Query></QueryList>'
+            Delay             = '00:00:45'
+        }
+    }
+}
+
 Configuration ScheduledTaskOnceDel
 {
     Import-DscResource -ModuleName ComputerManagementDsc
@@ -425,6 +463,25 @@ Configuration ScheduledTaskExecuteAsDel
     }
 }
 
+Configuration ScheduledTaskOnEventDel
+{
+    Import-DscResource -ModuleName ComputerManagementDsc
+    node 'localhost'
+    {
+        ScheduledTask ScheduledTaskOnEventDel
+        {
+            TaskName          = 'Test task OnEvent'
+            TaskPath          = '\ComputerManagementDsc\'
+            Ensure            = 'Absent'
+            ScheduleType      = 'OnEvent'
+            ActionExecutable  = 'C:\windows\system32\WindowsPowerShell\v1.0\powershell.exe'
+            ActionArguments   = '-Command Set-Content -Path c:\temp\seeme.txt -Value ''Worked!'''
+            EventSubscription = '<QueryList><Query Id="0" Path="System"><Select Path="System">*[System[Provider[@Name=''Service Control Manager''] and (Level=2) and (EventID=7001)]]</Select></Query></QueryList>'
+            Delay             = '00:00:30'
+        }
+    }
+}
+
 Configuration ScheduledTaskDisableBuiltIn
 {
     Import-DscResource -ModuleName ComputerManagementDsc

diff --git a/Tests/Integration/MSFT_ScheduledTask.Integration.Tests.ps1 b/Tests/Integration/MSFT_ScheduledTask.Integration.Tests.ps1
@@ -36,6 +36,7 @@ try
             AtLogon           = 'ScheduledTaskLogon'
             AtStartup         = 'ScheduledTaskStartup'
             ExecuteAs         = 'ScheduledTaskExecuteAs'
+            OnEvent           = 'ScheduledTaskOnEvent'
         }
 
         $configData = @{