SecureItem PowerShell Azure Function (with warmup bypass)

secureitem-after.ps1

# POST method: $req
$requestBody = Get-Content $req -Raw | ConvertFrom-Json
Write-Output $requestBody

if($requestBody -eq 'WARMUP'){
    
    #Exit - we are all warmed up!
    Out-File -Encoding Ascii -FilePath $res -inputObject "Warm up signal recieved." 

} else {

    #Execute the normal function logic
    $list = $requestBody.list
    $id = $requestBody.itemId
    $readAccess = $requestBody.readAccess
    $writeAccess = $requestBody.writeAccess

    #Connect to the SharePoint site
    Connect-PnPOnline -Url $env:SPUrl -AppId $env:AppId -AppSecret $env:AppSecret

    #Get the list item
    $item = Get-PnPListItem -List $list -Id $id

    #Give the item Author back write permission
    Set-PnPListItemPermission -List $list -Identity $id -User $item.FieldValues["Author"].Email -AddRole 'Contribute' -ClearExisting

    #Give read access for those that require it
    forEach($user in $readAccess) {
        Set-PnPListItemPermission -List $list -Identity $id -User $user -AddRole 'Read' 
    }

    #Give write access to those who require it
    forEach($user in $writeAccess) {
        Set-PnPListItemPermission -List $list -Identity $id -User $user -AddRole 'Contribute' 
    }

    #Send the response
    Out-File -Encoding Ascii -FilePath $res -inputObject "Updated security for: $list - $id"
}