Accessing variables in Azure loops using templates - azure-devops

Question

I want to loop through the pipeline artifacts and pass them as variables to a task.
Followed this answer here, but no luck:
https://stackoverflow.com/a/59451690/5436341
Have this powershell script in the build stage to get the artifact names and store them in a variable:
- task: PowerShell#2
inputs:
targetType: 'inline'
script: |
# Write your PowerShell commands here.
Write-Host "Fetching value files"
cd $(Build.ArtifactStagingDirectory)\MSI
$a=dir -Filter "*.msi"
$List = $a | foreach {$_}
Write-Host $List
$d = '"{0}"' -f ($List -join '","')
Write-Host $d
Write-Host "##vso[task.setvariable variable=MSINames;isOutput=true]$d"
name: getMSINames
And passing them as parameters to a template from another stage as below:
- stage: deployPoolsStage
displayName: Deploy Pools
dependsOn:
- Build
jobs:
- job: CloudTest_AgentBased_Job
displayName: 'CloudTest AgentBased Job'
timeoutInMinutes: 120
variables:
MSIFiles: $[dependencies.Build.outputs['getMSINames.MSINames']]
steps:
- template: TestPipeline.yml
parameters:
files : $(MSIFiles)
Now, my template looks like this:
parameters:
files : []
steps:
- ${{ each filename in parameters.files }}:
- task: SomeTask
inputs:
Properties: worker:VsTestVersion=V150;worker:MSIFile=${{ filename }}
displayName: 'tests'
Now this is failing with an error saying: "Expected a sequence or mapping. Actual value '$(MSIFiles)'". It's the same error even without using the template and directly accessing the variable in the original yml file.
Please let me know of a way to loop through my pipeline artifacts and pass them to my task.

Answer 1

You are exporting the variable MSINames from a task in Build stage that needs to be inside a job (say BuildJob). Also, you are trying to access the exported variable from another stage but inside a job. Thus, you should use the format to read variable from another stage but within a job. What you have used is a wrong format in deployPoolsStage stage. Try correcting the format as below inside CloudTest_AgentBased_Job job,
variables:
MSIFiles: $[stageDependencies.Build.BuildJob.outputs['getMSINames.MSINames']]
NOTE: I have assumed that the getMSINames task is defined inside the BuildJob job under Build stage according to what you have provided.
See docs related to this here.