Using composite variables in the ManualValidation@0 Azure DevOps task

Question

I'm trying to reuse some variable to generate the instructions of a ManualValidation@0 task.

The problem is that the task only seems to evaluate one "level" of variables, unlike for example the bash script.

My pipeline looks like this:

trigger:
- none

pool:
  vmImage: 'windows-latest'

variables:
  deploymentSlotName: 'preview-$(Build.BuildId)'
  deploymentSlotUrl: 'https://mywebapp-$(deploymentSlotName).azurewebsites.net/'

stages:
  - stage:
    jobs:
      - job: ConsoleStuff
        steps:
          - checkout: none
          - bash: |
              echo $(deploymentSlotName)
              echo $(deploymentSlotUrl)
            # This outputs:
            # preview-214296
            # https://mywebapp-preview-214296.azurewebsites.net/


      - job: ConfirmStuff
        pool: server
        steps:
        - task: ManualValidation@0
          displayName: Confirm this
          inputs:
            notifyUsers: ''
            instructions: 'SlotName: $(deploymentSlotName), SlotUrl: $(deploymentSlotUrl)'
            # This actually outputs: SlotName: preview-$(Build.BuildId), SlotUrl: https://mywebapp-$(deploymentSlotName).azurewebsites.net/

If I change the task to look like this, I get the correct output:

      - job: ConfirmStuff
        pool: server
        steps:
        - task: ManualValidation@0
          displayName: Confirm this
          inputs:
            notifyUsers: ''
            instructions: 'SlotName: preview-$(Build.BuildId), SlotUrl: https://mywebapp-preview-$(Build.BuildId).azurewebsites.net/'
            # This actually outputs: SlotName: preview-214296, SlotUrl: https://mywebapp-preview-214296.azurewebsites.net/

Is this a limitation of the task, or am I misunderstanding when the variables are evaluated?

Is there a nice way to do this, so I don't have to construct the same values multiple times?

I managed to use the original variables by setting them as output variables from a bash script, and then referencing them in the ConfirmStuff variables section, but that was a lot of code just to render a variable in a message.

Answer 1

Tested the same YAML sample and I can reproduce the same issue.

$(Build.BuildID) variable is a Runtime Variable. Refer to this doc: Predefined variables

When we use the nested variable contains the Runtime Variable(e.g. $(Build.BuildID)), Agentless job task cannot parse nested variables directly.

It can only parse the value of the first level of nested variables. $(deploymentSlotName) = preview-$(Build.BuildId)

This should be the limitation of the Agentless Job task.

To achieve your needs, we can only use Cross Stage variables for the time being.

For example:

trigger:
- none

pool:
  vmImage: 'windows-latest'

variables: 
  deploymentSlotName: preview-$(build.buildid)
  deploymentSlotUrl: 'https://mywebapp-$(deploymentSlotName).azurewebsites.net/'

stages:
  - stage:
    jobs:
      - job: ConsoleStuff
        steps:
          - checkout: none
          - bash: |
              echo $(deploymentSlotName)
              echo $(deploymentSlotUrl)
              echo "##vso[task.setvariable variable=deploymentSlotName;isoutput=true]$(deploymentSlotName)"
              echo "##vso[task.setvariable variable=deploymentSlotUrl;isoutput=true]$(deploymentSlotUrl)"
            name: passOutput


      - job: ConfirmStuff
        pool: server
        dependsOn: ConsoleStuff
        variables:
          deploymentSlotName: $[ dependencies.ConsoleStuff.outputs['passOutput.deploymentSlotName'] ]  
          deploymentSlotUrl: $[ dependencies.ConsoleStuff.outputs['passOutput.deploymentSlotUrl'] ]  

        steps:
        - task: ManualValidation@0
          displayName: Confirm this
          inputs:
            notifyUsers: ''
            instructions: 'SlotName: $(deploymentSlotName), SlotUrl: $(deploymentSlotUrl)'

Result:

On the other hand, if the nested variable uses a compile-time variable(e.g. ${{variables.['build.definitionname']}}), you can use the compile time variable format to define the variable:

For example:

variables: 
  deploymentSlotName: preview-${{variables.['build.definitionname']}}
  deploymentSlotUrl: 'https://mywebapp-${{variables.deploymentSlotName}}.azurewebsites.net/'

In this case, we can use the variable in agentless job task directly.