public/Get-VSAMachineGroup.ps1

function Get-VSAMachineGroup
{
    <#
    .Synopsis
        Returns Machine Groups.
    .DESCRIPTION
        Returns Machine Groups.
        Takes either persistent or non-persistent connection information.
    .PARAMETER VSAConnection
        Specifies established VSAConnection.
    .PARAMETER URISuffix
        Specifies URI suffix if it differs from the default.
    .PARAMETER MachineGroupID
        Specifies MachineGroup ID to get. All Machine Groups are returned if no MachineGroupID specified.
    .PARAMETER OrgID
        Specifies Organization ID to return machine groups that belong to.
        Please use {0} as a placeholder for OrgID in case a custom URISuffix provided.
    .PARAMETER Filter.
        Specifies REST API Filter.
    .PARAMETER Sort
        Specifies REST API Sorting.
    .PARAMETER ResolveIDs
        Return Organizations' info as well as their respective IDs.
    .PARAMETER Parallel
        Fetches the remaining pages of a large collection concurrently instead of one after another.
        Opt-in: without it, behaviour is unchanged. Results are identical either way (same records,
        merged in $skip order). Only engages once the collection is large enough to be worth it
        (see -ParallelThreshold).
    .PARAMETER ThrottleLimit
        Maximum number of concurrent requests when -Parallel is used (default 8). On shared SaaS you
        are one tenant among many, so a modest value is a good citizen; the engine also reduces
        concurrency automatically if the server returns HTTP 429, then recovers.
    .PARAMETER ParallelThreshold
        Minimum total record count before -Parallel actually engages. 0 (default) means automatic:
        two full throttle windows, i.e. 2 * ThrottleLimit * 100 records. Below that the sequential
        path is used, because it is faster than paying to set up extra connections. .EXAMPLE
       Get-VSAMachineGroup
    .EXAMPLE
       Get-VSAMachineGroup -OrgID '10001'
    .EXAMPLE
       Get-VSAMachineGroup -MachineGroupID '10001' -VSAConnection $connection
    .INPUTS
       Accepts piped non-persistent VSAConnection
    .OUTPUTS
       Array of objects that represent Machine Groups.
    #>

    [alias("Get-VSAMG")]
    [CmdletBinding()]
    param (
        [parameter(Mandatory = $false,
            ValueFromPipelineByPropertyName = $true,
            ParameterSetName = 'Organization')]
        [parameter(Mandatory = $false,
            ValueFromPipelineByPropertyName = $true,
            ParameterSetName = 'Group')]
        [ValidateNotNull()]
        [VSAConnection] $VSAConnection,

        [parameter(Mandatory=$true,
            ValueFromPipelineByPropertyName=$true,
            ParameterSetName = 'Organization',
            HelpMessage = "Please use {0} as a placeholder for OrgId in case a custom URISuffix provided.")]
        [ValidateScript({
            if( $_ -notmatch "^\d+$" ) {
                throw "Non-numeric Id"
            }
            return $true
        })]
        [string] $OrgId,

        [parameter(Mandatory = $false,
            ValueFromPipelineByPropertyName = $true,
            ParameterSetName = 'Group')]
        [ValidateScript({
            if( $_ -notmatch "^\d+$" ) {
                throw "Non-numeric Id"
            }
            return $true
        })]
        [string] $MachineGroupId,

        [parameter(DontShow,Mandatory = $false,

            ParameterSetName = 'Group')]
        [parameter(DontShow, Mandatory = $false,

            ParameterSetName = 'Organization',
            HelpMessage = "Please use {0} as a placeholder for OrgID in case a custom URISuffix provided.")]
        [ValidateNotNullOrEmpty()]
        [string] $URISuffix,

        [parameter(Mandatory = $false,
            ValueFromPipelineByPropertyName = $true,
            ParameterSetName = 'Group')]
        [parameter(Mandatory = $false,
            ValueFromPipelineByPropertyName = $true,
            ParameterSetName = 'Organization')]
        [ValidateNotNullOrEmpty()]
        [string] $Filter,

        [parameter(Mandatory = $false,
            ValueFromPipelineByPropertyName = $true,
            ParameterSetName = 'Group')]
        [parameter(Mandatory = $false,
            ValueFromPipelineByPropertyName = $true,
            ParameterSetName = 'Organization')]
        [ValidateNotNullOrEmpty()]
        [string] $Sort,

        [parameter(Mandatory = $false,
            ValueFromPipelineByPropertyName = $true,
            ParameterSetName = 'Group')]
        [parameter(Mandatory = $false,
            ValueFromPipelineByPropertyName = $true,
            ParameterSetName = 'Organization')]
        [switch] $ResolveIDs,

        # Opt-in parallel paging for large collections (see Invoke-VSARestMethod). No effect on small
        # ones: below -ParallelThreshold the sequential path is used.
        [parameter(Mandatory = $false)]
        [switch] $Parallel,

        [parameter(Mandatory = $false)]
        [ValidateRange(1, 64)]
        [int] $ThrottleLimit = 8,

        [parameter(Mandatory = $false)]
        [ValidateRange(0, [int]::MaxValue)]
        [int] $ParallelThreshold = 0
        )
    process {

        if ( $OrgId ) {
            #Machine groups for specific organization
            if( [string]::IsNullOrEmpty($URISuffix) ) { $URISuffix = "api/v1.0/system/orgs/{0}/machinegroups" }
            $URISuffix = $URISuffix -f $OrgId
        } else {
            #Machine groups for all organizations
            if( [string]::IsNullOrEmpty($URISuffix) ) { $URISuffix= "api/v1.0/system/machinegroups" }

            if( -not [string]::IsNullOrEmpty($MachineGroupId)) {
                $URISuffix = "{0}/{1}" -f $URISuffix, $MachineGroupId
            }
        }

        [hashtable]$Params = @{
            VSAConnection = $VSAConnection
            URISuffix     = $URISuffix
            Filter        = $Filter
            Sort          = $Sort
        }

        #Remove empty keys
        foreach ( $key in @($Params.Keys)  ) {
            if ( -not $Params[$key]) { $Params.Remove($key) }
        }

    # Forward the opt-in parallel controls to the shared read path, which owns the paging engine.
    if ($Parallel) {
        $Params['Parallel']      = $true
        $Params['ThrottleLimit'] = $ThrottleLimit
        if ($ParallelThreshold -gt 0) { $Params['ParallelThreshold'] = $ParallelThreshold }
    }
        $result = Invoke-VSARestMethod @Params

        if ($ResolveIDs)
        {
            [hashtable]$ResolveParams =@{}
            # F-26: this added VSAConnection to $Params (which already carries it) instead of to the
            # $ResolveParams passed to Get-VSAOrganization -> "Item has already been added" and the
            # resolve lookup ran with no connection. Add it to $ResolveParams.
            if ($VSAConnection) {$ResolveParams.Add('VSAConnection', $VSAConnection)}

            [hashtable]$OrganizationDictionary = @{}

            Foreach( $Organization in $(Get-VSAOrganization @ResolveParams) )
            {
                if ( -Not $OrganizationDictionary[$Organization.OrgId]) {
                    $OrganizationDictionary.Add($Organization.OrgId, $($Organization | Select-Object * -ExcludeProperty OrgId))
                }
            }

            $result = $result | Select-Object -Property *, `
                @{Name = 'Organization'; Expression = { $OrganizationDictionary[$_.OrgId] }}
        }

        return $result
    }
}
Export-ModuleMember -Function Get-VSAMachineGroup