How can I retrieve output from Azure PowerShell child Runbook (7.2) started by 'Start-AutomationRunbook' from within parent Runbook (also 7.2)?

Question

Title says it all, I guess.

I am trying to modularize my runbooks and all I want to do is start child RBs using the internal Automation module 'Start-AutomationRunbook' AND get back the result.

This is the sample code I am testing with:

Parent RB:

$result = Start-AutomationRunbook -Name ChildRB
Write-Output $result

Child RB:

$hello = 'Hello world!'
Write-Output $hello

However, instead of storing 'Hello world!' in $result the Job ID is sent to the console.

I have also been trying to use

Wait-AutomationJob

However, that returns GUID, status etc. but again not 'Hello, world!'. Tried to use the '-OutputJobsTransitionedToRunning' parameter as well, but that didn't do the trick either.

Unfortunately there is no real documentation about the internal Cmdlets for Azure Runbooks.

Any help is much appreciated.

Answer 1

Gordon Hesper, thank you for posting this question on Microsoft Q&A.

In order to get the Job output from the child runbook, use Get-AzAutomationJobOutput cmdlet from the Az.Automation module. Following is a sample script to start a child runbook, wait for it to complete and then get the output back.

#Using Managed Identity for Authentication - START
# Ensures you do not inherit an AzContext in your runbook
Disable-AzContextAutosave -Scope Process

# Connect to Azure with system-assigned managed identity
$AzureContext = (Connect-AzAccount -Identity).context

# Set and store context
$AzureContext = Set-AzContext -SubscriptionName $AzureContext.Subscription -DefaultProfile $AzureContext
#Using Managed Identity for Authentication -END

$result = Start-AutomationRunbook -Name ChildRB

#wait for the job to complete else you may get empty result which creates confusion
Wait-AutomationJob -Id $result

#get the output from child runbook.
$out = Get-AzAutomationJobOutput $result -ResourceGroupName "new-autoAcc" -AutomationAccountName "autoacc" -Stream "Any"

write-output $out.Summary

Note that "get-AzAutomationJobOutput" is not an internal automation cmdlet (hence the name contains "Az"). The only internal cmdlets as available are here - https://learn.microsoft.com/en-us/azure/automation/shared-resources/modules#internal-cmdlets

Hope this helps.

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