Restart application pool based on http response code - powershell

Question

I am trying to write a PowerShell script that will restart an application pool in IIS if a 503 response code is received.
So far I have managed to retrieve the response code for every crm application under the default website in IIS. However I am unsure how I would go about finding the application pool name. I've tried the below, but it returns the same application pool for each site. Can anyone help?
$getSite = (Get-WebApplication -Site 'Default Web Site')
$SiteURL = ForEach ($site in $getSite.path) {("http://localhost")+$site}
ForEach ($crm in $SiteURL){
$req = [system.Net.WebRequest]::Create($crm)
try {
$res = $req.GetResponse()
} catch [System.Net.WebException] {
$res = $_.Exception.Response
}
$ApplicationPool = ForEach ($app in $getSite.applicationpool) {$app}
if([int]$res.StatusCode -eq 503) {write-host ($crm + ' ' + [int]$res.StatusCode) + $app}
}

Answer 1

I think you need to access $_.Exception.InnerException for the the Response property.
Your $ApplicationPool assignment doesn't make much sense, as you would only need one applicationPool name per $crm app you test:
foreach($App in #(Get-WebApplication -Site 'Default Web Site')){
# Uri for the application
$TestUri = 'http://localhost{0}' -f $App.path
# Create WebRequest
$Request = [system.Net.WebRequest]::Create($TestUri)
try {
# Get the response
$Response = $Request.GetResponse()
} catch [System.Net.WebException] {
# If it fails, get Response from the Exception
$Response = $_.Exception.InnerException.Response
}
# The numerical value of the StatusCode value is the HTTP status code, ie. 503
if(503 -eq ($Response.StatusCode -as [int])){
# Restart the app pool
Restart-WebAppPool -Name $App.applicationPool
}
}