PowerShell script to convert an Azure DevOps Pipeline variable group to the equivalent YAML

Convert-VariableGroup.ps1

<#
.SYNOPSIS
    Convert Azure Pipelines Variable Group to YAML

.DESCRIPTION
    Reads a variable group from an Azure DevOps pipeline library and converts it into the equivalent YAML

.NOTES
    Requires the Azure CLI, with the azure-devops extension installed. eg. `az extension add --name azure-devops`

.PARAMETER GroupName
    The naem of the variable group

.PARAMETER Organisation
    The Azure DevOps organisation name

.PARAMETER Project
    The name of the Azure DevOps project

.PARAMETER Array
    Output using the YAML 'Array' syntax (-name: value:)

.EXAMPLE
    .\Convert-VariableGroup.ps1 -Organisation gardiner -GroupName "My Variable Group" -Project "GitHub Builds"
    Explanation of the function or its result. You can include multiple examples with additional .EXAMPLE lines
#>
param (
    [Parameter(Mandatory=$true)]
    [string]
    $GroupName,
    [string]
    $Organisation,
    [string]
    $Project,
    [switch]
    $Array
)

$ErrorActionPreference = 'Stop'

# Find id of group
$groups = (az pipelines variable-group list --organization "https://dev.azure.com/$Organisation" --project "$Project") | ConvertFrom-Json

$groupId = $groups | Where-Object { $_.name -eq $GroupName } | Select-Object -ExpandProperty id -First 1

$group = (az pipelines variable-group show --id $groupId --organization "https://dev.azure.com/$Organisation" --project "$Project") | ConvertFrom-Json

$group.variables | Get-Member -MemberType NoteProperty | ForEach-Object {

    if ($Array.IsPresent) {
        Write-Output "- name: $($_.Name)"
        Write-Output "  value: $($group.variables.$($_.Name).Value)"
    } else {
        Write-Output "  $($_.Name): $($group.variables.$($_.Name).Value)"
    }
}