Optimize for each variable powershell script - powershell

Question

$allResources = #()
$subscriptions=Get-AzSubscription
ForEach ($vsub in $subscriptions){
Select-AzSubscription $vsub.SubscriptionID
Write-Host
Write-Host "Working on "$vsub
Write-Host
$allResources += $allResources |Select-Object $vsub.SubscriptionID,$vsub.Name
$result=#()
$webapps = Get-AzWebApp
foreach($webapp in $webapps){
$Tier = (Get-AzResource -ResourceId $webapp.ServerFarmId).Sku.Tier
$SKU = (Get-AzAppServicePlan -ResourceGroupName $webapp.ResourceGroup).Sku.Size
$AppServiceName = (Get-AzAppServicePlan -ResourceGroupName $webapp.ResourceGroup).Name
$obj = [PSCustomObject]#{
TenantId = $vsub.TenantId
SubscriptionName = $vsub.Name
WebappName = $webapp.Name
ResourceGroup = $webapp.ResourceGroup
Hostname = $WebApp.DefaultHostName
PricingTier = $Tier
SKU = ($SKU -join ',')
AppServiceName = ($AppServiceName -join ',')
#State = $webapp.State
#Location = $webapp.Location
#AppType = $webapp.Kind
}
$result += $obj
$result | Export-Csv -Path "E:\webapps_filter.csv" -Append -NoTypeInformation
$input = 'E:\webapps_filter.csv'
$inputCsv = Import-Csv $input | Sort-Object * -Unique
$inputCsv | Export-Csv "E:\webapps.csv" -NoTypeInformation}}
Right now I am using the above script to fetch all the required data of web apps from all the subscriptions. Currently, the script is taking time to execute, I need to optimize it and also the script gives a duplicate output so in last have added the filter to sort out it by unique entry.

Answer 1

It seems you are adding stuff to an array variable $allResources you don't use, so get rid of that.
Instead of the costly (time/memory) $result += $obj, better let PowerShell collect the objects using $result = foreach(..)
You are appending a temporary file inside the foreach loop on each iteration, then import this file and filter it on all properties to become unique.
again, inside the loop you are exporting this uniqified data to a CSV file on every iteration
You are calling upon cmdlet Get-AzAppServicePlan twice to get different properties. Use it only once would save time
as aside, you should not use a self-defined variable called $input as this is an Automatic variable
Try:
$subscriptions = Get-AzSubscription
$result = foreach ($vsub in $subscriptions){
Select-AzSubscription $vsub.SubscriptionID
Write-Host
Write-Host "Working on $($vsub.Name)"
Write-Host
foreach($webapp in (Get-AzWebApp)){
$Tier = (Get-AzResource -ResourceId $webapp.ServerFarmId).Sku.Tier
$Plan = Get-AzAppServicePlan -ResourceGroupName $webapp.ResourceGroup
# output the object so it gets collected in $result
[PSCustomObject]#{
TenantId = $vsub.TenantId
SubscriptionName = $vsub.Name
SubscriptionID = $vsub.SubscriptionID
WebappName = $webapp.Name
ResourceGroup = $webapp.ResourceGroup
Hostname = $webapp.DefaultHostName
PricingTier = $Tier
SKU = #($Plan.Sku.Size) -join ','
AppServiceName = #($Plan.Name) -join ','
#State = $webapp.State
#Location = $webapp.Location
#AppType = $webapp.Kind
}
}
}
# sort unique and export the file
$result | Sort-Object * -Unique | Export-Csv -Path "E:\webapps.csv" -NoTypeInformation