Last time, we’d figured out a strategy for getting our data up into Azure Artifacts. The problem was that we are using SemVer pre-release notation, and the Azure Artifacts command line and Azure Pipelines task don’t support querying pre-release versions using wildcards.

The CLI tools and Pipelines task will work if we know the exact pre-release version required, but how to find that out? The Azure DevOps Services REST API.

Here’s an example PowerShell script you could use to find out the latest version of a package named ‘mypackage’. It sets a pipeline variable that can be used in subsequent Azure Pipeline tasks.

$url = "{organization}/{project}/_apis/packaging/Feeds/{feedId}/packages?api-version=5.1-preview.1&packageNameQuery=mypackage"

$base64AuthInfo = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(("{0}:{1}" -f "",$env:SYSTEM_ACCESSTOKEN)))
$result = Invoke-RestMethod -Uri $url -Method Get -ContentType "application/json" -Headers @{Authorization=("Basic {0}" -f $base64AuthInfo)}

$packageVersion = $result.value.versions.normalizedVersion
Write-Host "##vso[task.setvariable variable=packageVersion]$packageVersion"

We’re making use of the packageNameQuery parameter to filter by the package name, but there are other filtering options available. You could also do more filtering on the JSON data that the REST API returns.

Now we can use the Universal Package task, requesting the specific version. eg.

# Download Universal Package
- task: UniversalPackages@0
  displayName: 'Universal download'
    downloadDirectory: Application
    vstsFeed: '00000000-0000-0000-0000-000000000000/00000000-0000-0000-0000-000000000001'
    vstsFeedPackage: imagemagick
    vstsPackageVersion: '$(packageVersion)'