Useful PowerShell functions for working with local IIS sites and app pools

iishelpers.ps1

Import-Module IISAdministration

# Sets an environment variable for an IIS site in the applicationHost.config, rather than the web.config
# This allows for secrets to be stored securely, without any risk of them being added to source control.
function SetIISSiteEnvironmentVariable([string]$SiteName, [string]$Name, [string]$Value) {
    $sm = Get-IISServerManager
    $Env = $sm.GetApplicationHostConfiguration().GetSection("system.webServer/aspNetCore", $SiteName).
        GetChildElement("environmentVariables").
        GetCollection()

    $CurrentVariable = $Env.GetCollection() | Where-Object {$_["name"] -eq $Name}
    if ($CurrentVariable) {
        Write-Host "Setting existing environment variable $Name on site $SiteName"
        $CurrentVariable["value"] = $Value
    }
    else {
        Write-Host "Creating new environment variable $Name on site $SiteName"
        $NewVariable = $Env.CreateElement()
        $NewVariable["name"] = $Name
        $NewVariable["value"] = $Value
        $Env.Add($NewVariable) | out-null
    }
    $sm.CommitChanges()
}

function DeleteExistingIISWebSite([string]$SiteName) {
    $sm = Get-IISServerManager
    $CurrentSite = $sm.Sites[$SiteName]
    if ($CurrentSite) {
        Write-Host "Deleting existing site"
        $CurrentSite.Delete() | out-null
    }

    $CurrentPool = $sm.ApplicationPools[$SiteName]
    if ($CurrentPool) {
        Write-Host "Deleting existing app pool"
        $CurrentPool.Delete() | out-null
    }

    $sm.CommitChanges()
}

function CreateIISWebSite([string]$HostName, [string]$SiteName, [string]$SitePath) {
    Write-Host "$SiteName will use '$SitePath' as its physical path"
    
    DeleteExistingIISWebSite $SiteName
    $sm = Get-IISServerManager

    Write-Host "Creating app pool $SiteName"
    $NewPool = $sm.ApplicationPools.Add($SiteName)
    $NewPool.ProcessModel.IdentityType = "LocalSystem"
    $NewPool.ManagedRuntimeVersion = ""

    Write-Host "Creating site $SiteName"

    $NewSite = $sm.Sites.Add($SiteName, "http", ":80:$HostName", $SitePath)
    $NewSite.Bindings.Add(":443:$HostName", "https") | Out-Null

    Write-Host "Linking $SiteName app pool with site"
    $NewSite.Applications["/"].ApplicationPoolName = $SiteName

    $sm.CommitChanges()
}

function AssignSslCertificateToIISExpress([string]$HostName, [string]$CertThumbprint) {
    $HostNamePort = $HostName + ":443"
    $AppId = "{214124cd-d05b-4309-9af9-9caa44b2b74a}" # IIS Express

    Write-Host "Assigning self-signed cert to IIS Express for $HostName"
    netsh http delete sslcert hostnameport=$HostNamePort | out-null
    netsh http add sslcert hostnameport=$HostNamePort certhash=$CertThumbprint appid=$AppId certstorename=my
}

function AssignSslCertificateToIIS([string]$HostName, [string]$CertThumbprint) {
    $HostNamePort = $HostName + ":443"
    $AppId = "{4dc3e181-e14b-4a21-b022-59fc669b0914}" # IIS

    Write-Host "Assigning self-signed cert to IIS for $HostName"
    netsh http delete sslcert hostnameport=$HostNamePort | out-null
    netsh http add sslcert hostnameport=$HostNamePort certhash=$CertThumbprint appid=$AppId certstorename=my
}