Problems with Get-ScheduledJob and Try Catch Finally - powershell

In my PowerShell module, I'm using Get-ScheduledJob to list the currently scheduled jobs.
I'll manually delete jobs which ran successfully from the Task Scheduler which causes Get-ScheduledJob to throw a non-terminating error saying the job wasn't found and has been removed from the computer.
The weird problem I'm having is trying to wrap this non-terminating error in a try/catch/finally block to return a more meaningful error.
The incorrect behavior is the catch block runs, but the automatic variable $_ does not contain the current exception. As it's null, the -match statement returns False.
Am I missing something painfully obvious?
function ViewOnly {
try {
$try = Get-ScheduledJob -ErrorAction Stop
} catch {
$ErrorLine = $_.InvocationInfo.Line
$ErrorMessage = $_.Exception
[void]$ErrorMessage -match '[0-9-_]{13}\s(Server\sReboot)'
Write-Verbose "Errored at $ErrorLine"
Write-Warning "The scheduled Job $($Matches[0]) was not found, Run View-ECCReboots to verify servers rebooted"
} finally {
$jobs = Get-ScheduledJob
if ($jobs) {
$results = foreach ($job in $jobs) {
[pscustomobject]#{
Server = $job.Name
RebootTime = ($job | Get-JobTrigger).At
}
}
} else {
"No previously scheduled jobs found!"
} #end if
$results | Sort RebootTime | FT -Auto
} #end finally
} #end viewonly function.

Related

How to run a module within a Scriptblock in PowerShell?

I am currently trying to import a .psm1 file dynamically into a script block to execute it.
I am using parallelisation along with jobs as I need to trigger several modules simultaneously as different users.
This is the code:
$tasksToRun | ForEach-Object -Parallel {
$ScriptBlock = {
param ($scriptName, $Logger, $GlobalConfig, $scriptsRootFolder )
Write-Output ("hello $($scriptsRootFolder)\tasks\$($scriptName)")
Import-Module ("$($scriptsRootFolder)\tasks\$($scriptName)")
& $scriptName -Logger $Logger -GlobalConfig $GlobalConfig
}
$job = Start-Job -scriptblock $ScriptBlock `
-credential $Cred -Name $_ `
-ArgumentList ($_, $using:Logger, $using:globalConfig, $using:scriptsRootFolder) `
Write-Host ("Running task $_")
$job | Wait-job -Timeout $using:timeout
if ($job.State -eq 'Running') {
# Job is still running, stop it
$job.StopJob()
Write-Host "Stopped $($job.Name) task as it took too long"
}
else {
# Job completed normally, get the results
$job | Receive-Job
Write-Host "Finished task $($job.Name)"
}
}
The logger variable is a hashtable as defined here:
$Logger = #{
generalLog = $function:Logger
certificateLog = $function:LoggerCertificate
alertLog = $function:LoggerAlert
endpointServiceLog = $function:LoggerEndpointService
}
Currently, it is erroring with the following:
ObjectNotFound: The term
' blah blah blah, this is the code straight from the logger function '
is not recognized as the name of a cmdlet, function, script file, or operable program.
Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
The logger function servers the purpose of logging to a file in a specific way, it is generalised to that it can be used across many tasks.
A cut down example of a logger (probably won't compile, just deleted a bunch of lines to give you the general idea):
function LoggerEndpointService {
param (
# The full service name.
[string]$ServiceFullName,
# The unique identifier of the service assigned by the operating system.
[string]$ServiceId,
# The description of the service.
[string]$Description,
# The friendly service name.
[string]$ServiceFriendlyName,
# The start mode for the service. (disabled, manual, auto)
[string]$StartMode,
# The status of the service. (critical, started, stopped, warning)
[string]$Status,
# The user account associated with the service.
[string]$User,
# The vendor and product name of the Endpoint solution that reported the event, such as Carbon Black Cb Response.
[string]$VendorProduct
)
$ServiceFullName = If ([string]::IsNullOrEmpty($ServiceFullName)) { "" } Else { $ServiceFullName }
$ServiceId = If ([string]::IsNullOrEmpty($ServiceId)) { "" } Else { $ServiceId }
$ServiceFriendlyName = If ([string]::IsNullOrEmpty($ServiceFriendlyName)) { "" } Else { $ServServiceFriendlyNameiceName }
$StartMode = If ([string]::IsNullOrEmpty($StartMode)) { "" } Else { $StartMode }
$Status = If ([string]::IsNullOrEmpty($Status)) { "" } Else { $Status }
$User = If ([string]::IsNullOrEmpty($User)) { "" } Else { $User }
$Description = If ([string]::IsNullOrEmpty($Description)) { "" } Else { $Description }
$VendorProduct = If ([string]::IsNullOrEmpty($VendorProduct)) { "" } Else { $VendorProduct }
$EventTimeStamp = Get-Date -Format "yyyy-MM-ddTHH:mm:ssK"
$Delay = 100
For ($i = 0; $i -lt 30; $i++) {
try {
$logLine = "{{timestamp=""{0}"" dest=""{1}"" description=""{2}"" service=""{3}"" service_id=""{4}""" `
+ "service_name=""{5}"" start_mode=""{6}"" vendor_product=""{7}"" user=""{8}"" status=""{9}""}}"
$logLine -f $EventTimeStamp, $env:ComputerName, $Description, $ServiceFullName, $ServiceId, $ServiceFriendlyName, $StartMode, $VendorProduct, $User, $Status | Add-Content $LogFile -ErrorAction Stop
break;
}
catch {
Start-Sleep -Milliseconds $Delay
}
if ($i -eq 29) {
Write-Error "Alert logger failed to log, likely due to Splunk holding the file, check eventlog for details." -ErrorAction Continue
if ([System.Diagnostics.EventLog]::SourceExists("SDOLiveScripts") -eq $False) {
Write-Host "Doesn't exist"
New-EventLog -LogName Application -Source "SDOLiveScripts"
}
Write-EventLog -LogName "Application" -Source "SDOLiveScripts" `
-EventID 1337 `
-EntryType Error `
-Message "Failed to log to file $_.Exception.InnerException.Message" `
-ErrorAction Continue
}
}
}
Export-ModuleMember -Function LoggerEndpointService
If anyone could help that'd be great, thank you!
As mentioned in the comments, PowerShell Jobs execute in separate processes and you can't share live objects across process boundaries.
By the time the job executes, $Logger.generalLog is no longer a reference to the scriptblock registered as the Logger function in the calling process - it's just a string, containing the definition of the source function.
You can re-create it from the source code:
$actualLogger = [scriptblock]::Create($Logger.generalLog)
or, in your case, to recreate all of them:
#($Logger.Keys) |ForEach-Object { $Logger[$_] = [scriptblock]::Create($Logger[$_]) }
This will only work if the logging functions are completely independent of their environment - any references to variables in the calling scope or belonging to the source module will fail to resolve!

Try/catch is not working with Start-Service

My problem is really simple (I think). To catch when a service cannot be started and throw a message. Really the only reason it should fail is if the service is disabled but I want to let the user know that. I saw this post but none of the answers seemed to help since they're talking about filtering the catch with if statements and I can't even seem to get a basic catch working like so:
Write-Host "Starting Services ..."
$svc = Get-Service -DisplayName "*lar*" | where { $_.Status -Like "Stop*" }
if ( $svc )
{
foreach ( $item in $svc )
{
Write-Host "Starting"$item.Name
try { Start-Service $item.Name
}
catch {
Write-Host "Could not start service:" $item.Name
}
}
}
I do get an error when running, but not my write-host message in the catch
Start-Service on a disabled service throws a non-terminating error. For catch to work, you need a terminating error. You can force the error to be terminating by using -ErrorAction Stop.
try {
Start-Service $item.Name -ErrorAction Stop
}
catch {
Write-Host "Could not start service:" $item.Name
}

How I can pass multiple array in value in PowerShell function

Below function I want to pass multiple value in array. When I'm passing more than one value I am getting an error.
function CheckProcess([String[]]$sEnterComputerNameHere, [String[]]$sEnterProccessNameHere) {
#Write-Host " $sEnterComputerNameHere hello"
#($sEnterComputerNameHere) | ForEach-Object {
# Calling Aarray
#($sEnterProccessNameHere) | ForEach-Object {
if (Get-Process -ComputerName $sEnterComputerNameHere | where {$_.ProcessName -eq $sEnterProccessNameHere}) {
Write-Output "$_ is running"
} else {
Write-Output "$_ is not running"
}
}
}
}
$script:sEnterProccessNameHere = #("VPNUI") # Pass the process agreement here
$script:sEnterComputerNameHere = #("hostname") # Pass the process agreement here
CheckProcess $sEnterComputerNameHere $sEnterProccessNameHere
Give it a try with this one:
Function CheckProcess([String[]]$sEnterComputerNameHere,[String[]]$sEnterProccessNameHere)
{ #Write-host " $sEnterComputerNameHere"
#($sEnterComputerNameHere) | Foreach-Object {
$computer = $_
Write-Host $computer
#($sEnterProccessNameHere) | Foreach-Object {
$process = $_
Write-Host $process
try{
$x = get-process -computername $computer #Save all processes in a variable
If ($x.ProcessName -contains $process) #use contains instead of equals
{
Write-Output "$process is running"
}
else
{
Write-Output "$process is not running"
}
}
catch
{
Write-Host "Computer $computer not found" -ForegroundColor Yellow
}
}
}
}
$script:sEnterProccessNameHere = #("VPNUI","Notepad++","SMSS")
$script:sEnterComputerNameHere = #("remotecomputer1","remotecomputer2")
CheckProcess -sEnterComputerNameHere $sEnterComputerNameHere -sEnterProccessNameHere $sEnterProccessNameHere
In general, it would be great if you write the error you get in your question. That helps others to help you.
If I work with arrays and | Foreach, I always write the $_in a new variable. That helps if I have another | Foreach (like you had) to know for sure, with which object I'm working with..
EDIT: I changed the script, so it uses "-contains" instead of "-eq" and I added a try/catch block, so if the other computer is not found, it gives you a message.. It works on my network
EDIT2: Do you have access to the other computers? If you run get-process -computername "name of remote computer" do you get the processes?

Catching errors in Powershell

I have weird problem, when im using try/catch method for some cmdlets its working for some not.
Can you advice on that?
This one is working fine:
try
{
$LookingForRemoteMailboxOnPrem = Get-RemoteMailbox $info -ErrorAction Stop | select -ExpandProperty UserPrincipalName
}
catch
{
string]$t = $Error[0]
}
But this one is not:
try
{
$EnableRemoteMailbox = Enable-RemoteMailbox $info -RemoteRoutingAddress $remote -PrimarySmtpAddress $info2 -ErrorAction Stop
}
catch
{
[string]$t = $Error[0]
}
Not saving error to $t variable
The $ErrorActionPreference is set to Continue by default. This means if PowerShell can "recover" from an error it won't throw an exception. You can use the -ErrorAction parameter to change the behaviour at every cmdlet.
This link gives a good example:
Try {dir c:\missingFolder}
Catch [System.Exception] {"Caught the exception"}
Finally {$error.Clear() ; "errors cleared"}
The string "Caught the exception does not occur in PowerShell windows. If you set the -ErrorAction to Stop an exception is raised.
Details are described here.

Start-DscConfiguration doesn't throw exceptions?

I noticed that if applying a configuration through Start-DscConfiguration fails, it writes to the error stream but doesn't
throw an Exception? That is, if I do the following:
try{
Start-DscConfiguration -Path ".\MyConfig" -Wait -Verbose
}catch{
#...
}
...it never ends up in the catch handler. I suspect this may have something to do with the fact that without the "-Wait",
Start-DscConfiguration starts an async job for this, and async commands probably don't throw exceptions, but in a synchronous
scenario, I would very much like to know if my configuration could be applied.
What is the proper way to determine if Start-DscConfiguration has completed succesfully?
The only way I know is to check the global "$error" variable and compare the number of error records before and after your call to Start-DscConfiguration. If there's more afterwards then something must have gone wrong during the call, so throw your own exception:
Configuration TestErrorHandling {
Node "localhost" {
Script ErroringResource {
GetScript = { return $null; }
TestScript = { return $false; }
SetScript = { throw new-object System.InvalidOperationException; }
}
}
}
$errorCount = $error.Count;
write-host "starting dsc configuration"
$mof = TestErrorHandling;
Start-DscConfiguration TestErrorHandling –Wait –Verbose;
write-host "dsc configuration finished"
if( $error.Count -gt $errorCount )
{
$dscErrors = $error[$errorCount..($error.Count - 1)];
write-host "the following errors occurred during dsc configuration";
write-host ($dscErrors | fl * | out-string);
throw $dscErrors[-1];
}
There's another way to make it cause an exception. Try saving it into the ErrorVariable like this :
try
{
Start-DscConfiguration -Path ".\MyConfig" -Wait -Verbose -ErrorVariable ev
}
catch
{
$myException = $_
}
Weirdly so, this throws the exception when there's an error (which is what you wanted). You can get the value of your exception in the $myexception variable, and also could get just a one liner description of your error using $ev
PS: Note that while mentioning ev in the errorVariable parameter, you do it without the '$' symbol - since you're only specifying the variable 'name'.
Start-DscConfiguration when used without -Wait will create a job object - with one child job for every computername. PowerShell job objects have an Error stream which contains all the errors. You can check this stream as well
$job = Start-DscConfiguration -Force -Verbose -Path C:\Temp\Demo\ -ComputerName localhost
Receive-Job $job -Wait
'Errors in job = ' + ($job.childjobs[0].Error.Count)