struggling with scheduled task creation

[halr9000]

I am so close I can feel it! I've been trying to port an example seen in the programming guide (http://www.vmware.com/support/developer/vc-sdk/visdk25pubs/visdk25programmingguide.pdf) p. 163 "Creating a Scheduled Task". I had to leap a few hurdles and now at the end I'm stumped again. Here's the code and the error:

# Find object on which to perform action
$vmview = Get-View (Get-VM SDK-XPSP2).ID
$maa = New-Object VMware.Vim.MethodActionArgument
$maa.Value = $vmview.MoRef
$ma = New-Object VMware.Vim.MethodAction
$ma.Argument = $maa
$ma.Name = "powerOnVM"
$dTScheduler = New-Object VMware.Vim.DailyTaskScheduler
$dTScheduler.Hour = 18
$dTScheduler.Minute = 08
$tSpec = New-Object VMware.Vim.ScheduledTaskSpec
$tSpec.Description = "Start virtual machine according to schedule."
$tSpec.Enabled = $TRUE
$tSpec.Name = "Power On Virtual Machine"
$tSpec.Action = $ma
$tSpec.Scheduler = $dTScheduler
$tSpec.Notification = "hal@halr9000.com"
$vc = New-Object VMware.Vim.VimClient
$stmMoRef = New-Object VMware.Vim.ManagedObjectReference
$stm = New-Object VMware.Vim.ScheduledTaskManager $vc,$stmMoRef
$stm.CreateScheduledTask($vmview.MoRef, $tSpec)

The lsat four lines are what is giving me trouble. Took me a while to determine what obj types the ScheduledTaskManager wanted... But I am not satisfied that I did $vc & stmMoRef correctly. The error I receive is:

cheduletask test.ps1'

Exception calling "CreateScheduledTask" with "2" argument(s): "Object reference not set to an instance of an object."

At C:\documents and settings\hrottenberg\my documents\windowspowershell\scripts\book\scheduletask test.ps1:21 char:25

+ $stm.CreateScheduledTask <<<< ($vmview.MoRef, $tSpec)

Any pointers would be helpful.

-hal

Hal Rottenberg

Co-Host, PowerScripting Podcast (http://powerscripting.net)

[LucD · Accepted solution]

Hal, you were very close but the SDK Programming Guide put you on the wrong foot.

This should do the trick

# Find object on which to perform action
$vmview = Get-View (Get-VM <guest-name>).ID
$esxview = Get-View (Get-VMHost <ESX-hostname>).ID

$maa = New-Object VMware.Vim.MethodActionArgument
$maa.Value = $esxview.MoRef
$ma = New-Object VMware.Vim.MethodAction
$ma.Argument = $maa
$ma.Name = "PowerOnVM_Task"
$dTScheduler = New-Object VMware.Vim.DailyTaskScheduler
$dTScheduler.Hour = 18
$dTScheduler.Minute = 08
$dTScheduler.Interval = 1
$tSpec = New-Object VMware.Vim.ScheduledTaskSpec
$tSpec.Action = $ma
$tSpec.Description = "Start virtual machine according to schedule."
$tSpec.Enabled = $TRUE
$tSpec.Name = "Power On Virtual Machine"
$tSpec.Notification = "hal@halr9000.com"
$tSpec.Scheduler = $dTScheduler

$svcRef = new-object VMware.Vim.ManagedObjectReference
$svcRef.Type = "ServiceInstance"
$svcRef.Value = "ServiceInstance"
$serviceInstance = get-view $svcRef

$stMgr = Get-View ($serviceInstance.Content.ScheduledTaskManager)

$stMgr.CreateScheduledTask($vmview.MoRef,$tSpec)

Note1: the action name, contrary to SDK Prog Guide, is "PowerOnVM_Task"

Note2: I used the ServiceInstance to get at the ScheduledTaskManager

Note3: the MethodActionArgument wants the ESX host on which to run the task. The name of the guest is passed in CreateScheduledTask method

Note4: the DailyTaskScheduler.Interval property (which comes from the RecurrentTaskScheduler object) apparently can't be empty or 0

[ykalchev]

I've just want to add 2 minor notes to LucD's script.

1. There is no need to get VM's host view. The host MoREf is stored to VM's Runtime.Host property

$maa = New-Object VMware.Vim.MethodActionArgument
$maa.Value = $vmview.runtime.host

2. Because API docs says that ScheduledTaskManager is a singleton object you can just do:

$stMgr = Get-View ScheduledTaskManager-ScheduledTaskManager
$stMgr.CreateScheduledTask($vmview.MoRef,$tSpec)

Regards,

Yasen

[LucD]

Is the code in your 2nd note correct ?

If yes, would you mind elaborating on this because I don't really see what you do with this statement

$stMgr = Get-View ScheduledTaskManager-ScheduledTaskManager

[ykalchev]

As you know Get-View MoRef parameter can take ManagedObjectReference or string in format &lt;type&gt;-&lt;value&gt;. For example when you get view from VIObject you use the ID string property

$vmview = Get-View (Get-VM <vm-name>).ID  # // VM Id is sothething like VirtualMachine-vm-220

So instead of

$svcRef = new-object VMware.Vim.ManagedObjectReference
$svcRef.Type = "ServiceInstance"
$svcRef.Value = "ServiceInstance"
$serviceInstance = get-view $svcRef

you can just write:

$serviceInstance = Get-View ServiceInstance-ServiceInstance

The singleton API objects are like ServiceInstance, AlarmManager, SheduledTaskManager objects have MoRef's values that are unique and even more - for most of them their values are the same as their types

So to get the instance of the singleton object you can do

$svcRef = new-object VMware.Vim.ManagedObjectReference
$svcRef.Type = "ServiceInstance" ["AlarmManager"] ["SheduledTaskManager"]
$svcRef.Value = "ServiceInstance" ["AlarmManager"] ["SheduledTaskManager"]
get-view $svcRef

or

Get-View ServiceInstance-ServiceInstance
Get-View AlarmManager-AlarmManager
Get-View SheduledTaskManager-SheduledTaskManager

I hope I manage to light up a little this strange looking statement

[halr9000]

Ahh, sweet. Look for some interesting stuff to come of this, I think.

I'm good with PowerShell but I have a lot to learn about the VI SDK... Thanks Luc & yk!

Hal Rottenberg

Co-Host, PowerScripting Podcast (http://powerscripting.net)

[LucD]

Thanks for sharing this info.

No, I didn't know that Get-View accepted a string in that format.

Can't seem to find that option in the VI Toolkit Cmdlets reference either.

[halr9000]

No, I didn't know that Get-View accepted a string in that format.

Can't seem to find that option in the VI Toolkit Cmdlets reference either.

Don't get used to it, stuff like that changes. :smileygrin:

P.S. I use "get-command | select -expand parametersets | select -expand parameters" a lot.

Hal Rottenberg

Co-Host, PowerScripting Podcast (http://powerscripting.net)

[halr9000]

$ma.Name = "PowerOnVM_Task"

Note1: the action name, contrary to SDK Prog Guide, is "PowerOnVM_Task"

Will this always equal the name of a method?

Note2: I used the ServiceInstance to get at the ScheduledTaskManager

Where's that documented, do you know?

Hal Rottenberg

Co-Host, PowerScripting Podcast (http://powerscripting.net)

[LucD]

No clue. I discovered that through reverse engineering.

Create a scheduled task with the VI client and then investigate the properties with the MOB browser - the SDK programmer's best friend

The SDK Programming Guide states on p34 "The ServiceInstance managed object (Figure 2-4) is the central access point to all services and objects on the server.".

You can use the MOB browser (p32 of the same guide) to look at this structure.

[mbanusife]

Where do we find this MOB Browser?

[LucD]

Is included in the VC.

Just do

https://<VC-server>/mob

and logon with a VC account with the required permissions

[mbanusife]

Thanks...Could you give a quick run-down of what you do with this?

[harkamal]

Hi LucD,

Following you script, I tried to run a script as a scheduled job. This is supported in API, but I am not able to even make it work.

Two issues..

1. I need to apply this to datacenter (which is a managed entity, so should not be a problem), not to a host or vm

2. I get error when I run below script

Exception calling "CreateScheduledTask" with "2" argument(s): "A specified parameter was not correct. " At C:\HK-WorkArea\VmWare\PS-Scripts-v1.0.1\stm.ps1:27 char:27 + $stMgr.CreateScheduledTask( &lt;&lt;&lt;&lt; $dc.MoRef , $tSpec)

-

---

#Find object on which to perform action (wish to apply task to "DataCenters" object)

$dc = Get-Datacenter | Get-View

#RunScript Action

$rsa = New-Object VMware.Vim.RunScriptAction

$rsa.Script = "C:\WINDOWS\system32\WindowsPowerShell\v1.0\powershell.exe -command 'd:\test.ps1'"

#Scheduler

$dTScheduler = New-Object VMware.Vim.DailyTaskScheduler

$dTScheduler.Hour = 18

$dTScheduler.Minute = 08

$dTScheduler.Interval = 1

#Scheduled Task Spec

$tSpec = New-Object VMware.Vim.ScheduledTaskSpec

$tSpec.Action = $rsa

$tSpec.Description = "My Script Scheduling"

$tSpec.Enabled = $TRUE

$tSpec.Name = "Test Sched."

$tSpec.Notification =

$tSpec.Scheduler = $dTScheduler

#Create Scheduled Task

$serviceInstance = get-view ServiceInstance

$stMgr = Get-View ($serviceInstance.Content.ScheduledTaskManager)

$stMgr.CreateScheduledTask( $dc.MoRef , $tSpec)