PowerShell script used in an Azure Function to start all VMs in a resource group

StartVMInRG-Function.ps1

#This Azure Function is used to start VMs within a resource group
# It was originally created for eplansTest virtual machines, as a self-service endeavor.
# Calling the Function manually:
<#
    $Body = @"
    {
        "resourcegroup": "source-rg",
        "action": "start",
        "subscriptionid": "<subID>",
        "tenantid": "<azure AD tenant ID"
    }
    "@
    $URI = "https://hostname.azurewebsites.net/api/startVMs?code=FUNCTIONKEY"
    Invoke-RestMethod -Uri $URI -Method Post -body $body
#>

using namespace System.Net

# Input bindings are passed in via param block.
param($Request, $TriggerMetadata)

# Write to the Azure Functions log stream.
#Write-Host "PowerShell HTTP trigger function processed a request."

# Interact with query parameters or the body of the request.
$rgname = $Request.Query.resourcegroup
if (-not $rgname) {
    $rgname = $Request.Body.resourcegroup
}
$action = $Request.Query.action
if (-not $action) {
    $action = $Request.Body.action
}
$subscriptionid = $Request.Query.subscriptionid
if (-not $subscriptionid) {
    $subscriptionid = $Request.Body.subscriptionid
}
$tenantid = $Request.Query.tenantid
if (-not $tenantid) {
    $tenantid = $Request.Body.tenantid
}

#Proceed if all request body parameters are found
if ($rgname -and $action -and $subscriptionid -and $tenantid) {
    $status = [HttpStatusCode]::OK
    Select-AzSubscription -SubscriptionID $subid -TenantID $tenantid
    if ($action -ceq "get") {
        $body = Get-AzVM -ResourceGroupName $rgname -status | select-object Name, PowerState
    }
    if ($action -ceq "start") {
        $body = $action
        $body = Get-AzVM -ResourceGroupName $rgname | Start-AzVM -AsJob
    }
}
else {
    $status = [HttpStatusCode]::BadRequest
    $body = "Please pass a name on the query string or in the request body."
}

# Associate values to output bindings by calling 'Push-OutputBinding'.
Push-OutputBinding -Name Response -Value ([HttpResponseContext]@{
        StatusCode = $status
        Body       = $body
    })