Cannot set powershell output variables in Devops step

Question

I am trying to use an output variable from a powershell script. I'm using Devops online using the classic UI and tried both powershell 4.* and Powershell 5.* tasks in a release pipeline.

I am using a self-hosted agent that is working and doing lots of other build and release powershell stuff just fine. Azure Powershell modules version 3.5.0 (there is a reason for not using 4.x right now).

To simplify it, here is my test inline script in total...:

Write-Host '##vso[task.setvariable variable=MobileAppInsightsKey;isOutput=true;]thisisthekey'
Write-Host "This is host"

Write-Output '##vso[task.setvariable variable=MobileAppInsightsKey;isOutput=true;]thisisthekey'
Write-Output "This is output"

Here is the output from the Azure powershell task. (4.*)

2020-07-01T00:06:57.2970494Z ##[section]Starting: Azure PowerShell script: InlineScript
2020-07-01T00:06:57.3335882Z 
==============================================================================
2020-07-01T00:06:57.3336692Z Task         : Azure PowerShell
2020-07-01T00:06:57.3337292Z Description  : Run a PowerShell script within an Azure environment
2020-07-01T00:06:57.3337566Z Version      : 4.171.1
2020-07-01T00:06:57.3338039Z Author       : Microsoft Corporation
2020-07-01T00:06:57.3338575Z Help         : https://aka.ms/azurepowershelltroubleshooting
2020-07-01T00:06:57.3338930Z 
==============================================================================
2020-07-01T00:06:58.5902105Z ## Validating Inputs
2020-07-01T00:06:58.5915067Z ## Validating Inputs Complete
2020-07-01T00:06:58.5924850Z ## Initializing Az module
2020-07-01T00:06:59.0747435Z ##[command]Import-Module -Name C:\Program 
Files\WindowsPowerShell\Modules\Az.Accounts\1.9.0\Az.Accounts.psd1 -Global
2020-07-01T00:07:00.0802372Z ##[command]Clear-AzContext -Scope Process
2020-07-01T00:07:01.5597330Z ##[command]Clear-AzContext -Scope CurrentUser -Force -ErrorAction SilentlyContinue
2020-07-01T00:07:01.9691282Z ##[command]Connect-AzAccount -Identity @processScope
2020-07-01T00:07:03.1860248Z ##[command] Set-AzContext -SubscriptionId 5ec8ec06-XXXX-XXXX-XXXX- c0ff86c50e4 -TenantId ***
2020-07-01T00:07:03.9196710Z ## Az module initialization Complete
2020-07-01T00:07:03.9203692Z ## Beginning Script Execution
2020-07-01T00:07:03.9674782Z ##[command]& 'C:\DevOps\_work\_temp\1b1b130b-4306-448b-b4b2-e7daefc2382e.ps1' 
2020-07-01T00:07:03.9974844Z This is host
2020-07-01T00:07:04.0101140Z This is output
2020-07-01T00:07:04.0517610Z ##[command]Disconnect-AzAccount -Scope Process -ErrorAction Stop
2020-07-01T00:07:04.4795714Z ##[command]Clear-AzContext -Scope Process -ErrorAction Stop
2020-07-01T00:07:04.9468120Z ## Script Execution Complete
2020-07-01T00:07:04.9857991Z ##[section]Finishing: Azure PowerShell script: InlineScript

Note that "This is Host" and "This is Output" both display but the "##vso[...." does not.

Also the MobileAppInsightsKey I am trying to read in a subsequent step is empty (uninitialized).

Hopefully someone can point me in the right direction.

Thanks, Mark.

Answer 1

And to make a clear description about this issue:

To define a job-scoped variable in your scenario, we don't need to add isOutput=true;

1.For job-scoped variable(Variable is only valid in current job):

Write-Host '##vso[task.setvariable variable=MobileAppInsightsKey]thisisthekey' is enough. And we can output its value via format $(MobileAppInsightsKey) in CMD task.

2.For multi-job output variable(Variable is valid in multi-job):

We should use Write-Host '##vso[task.setvariable variable=MobileAppInsightsKey;isOutput=true;]thisisthekey'.

In current job: You can use $(referencename.variablename) to get its value. (Support classic pipeline and yaml pipeline)

In subsequent jobs: Use below format to access the variable, and this format only supports yaml pipeline!!!

- job: B
  dependsOn: A
  pool:
    vmImage: 'ubuntu-16.04'
  variables:
    myVarFromJobA: $[ dependencies.A.outputs['setvarStep.myOutputVar'] ]  # map in the variable
                                                                          # remember, expressions require single quotes
  steps:
  - script: echo $(myVarFromJobA)
    name: echovar

So for your scenario in which you want to access the variable in same job, just remove the isOutput=true;(it's not necessary). Or use $(referencename.variablename) format if you add isOutput=true; in the statement. (Not necessary, not recommended, but it should also work for current job)

In addition:

Details about $(referencename.variablename) format.

For Classic pipeline:(Set name as Test in Powershell task)

$(Test.MobileAppInsightsKey) represents the value of the variable.

For yaml pipeline:

  - powershell: echo "##vso[task.setvariable variable=myOutputVar;isOutput=true]this is the value"
    name: Test
  - script: echo $(Test.myOutputVar)