Powershell: IIS, Microsoft.Web.Administration, Import-Module WebAdministration, PSSnapin WebAdministration

iis-7modulepowershellweb-administration

I use VS2010, PowerShell v2.0, Windows Server 2008 R2 Standard for create deploy scripts ps1 for web applications (IIS 7).

I want manage IIS 7 (websites, appPools, virtualDirs, etc) programmatically using Powershell.

I'm confused about several ways for manage IIS using Powershell.

Which is recommended way about it?

1). Using Microsoft.Web.Administration.dll

[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.Web.Administration")

2). Using Import-Module vs Add-PSSnapin, according OS version or IIS version (¿?)

Detect OS version:

if ([System.Version] (Get-ItemProperty -path "HKLM:\Software\Microsoft\Windows NT\CurrentVersion").CurrentVersion -ge [System.Version] "6.1") { Import-Module WebAdministration } else { Add-PSSnapin WebAdministration }

Detect IIS version

$iisVersion = Get-ItemProperty "HKLM:\software\microsoft\InetStp";
if ($iisVersion.MajorVersion -eq 7)
{
    if ($iisVersion.MinorVersion -ge 5)
    {
        Import-Module WebAdministration;
    }           
    else
    {
        if (-not (Get-PSSnapIn | Where {$_.Name -eq "WebAdministration";})) {
            Add-PSSnapIn WebAdministration;
        }
    }
}

Module loaded and load as Snapin:

$ModuleName = "WebAdministration"
$ModuleLoaded = $false
$LoadAsSnapin = $false

if ($PSVersionTable.PSVersion.Major -ge 2)
{
    if ((Get-Module -ListAvailable | ForEach-Object {$_.Name}) -contains $ModuleName)
    {
        Import-Module $ModuleName
        if ((Get-Module | ForEach-Object {$_.Name}) -contains $ModuleName)
        {
            $ModuleLoaded = $true
        }
        else
        {
            $LoadAsSnapin = $true
        }
    }
    elseif ((Get-Module | ForEach-Object {$_.Name}) -contains $ModuleName)
    {
        $ModuleLoaded = $true
    }
    else
    {
        $LoadAsSnapin = $true
    }
}
else
{
    $LoadAsSnapin = $true
}

if ($LoadAsSnapin)
{
    if ((Get-PSSnapin -Registered | ForEach-Object {$_.Name}) -contains $ModuleName)
    {
        Add-PSSnapin $ModuleName
        if ((Get-PSSnapin | ForEach-Object {$_.Name}) -contains $ModuleName)
        {
            $ModuleLoaded = $true
        }
    }
    elseif ((Get-PSSnapin | ForEach-Object {$_.Name}) -contains $ModuleName)
    {
        $ModuleLoaded = $true
    }
}

References:
http://forums.iis.net/t/1166784.aspx/1

PowerShell: Load WebAdministration in ps1 script on both IIS 7 and IIS 7.5

Best Answer

Since you say you are using Server 2008 R2 and Powershell V2 or higher, Import-Module is the preferred method. Modules are more powerful than snapins and add a lot more functionality. However the biggest difference is that Modules do not need to be registered (added to the registry).

Snapins are a legacy feature from Powershell V1 which didn't support modules. Server 2008 (Orignal Recipe) did not have V2 out of the box, and still used snapins for IIS, ActiveDirectory, Exchange, etc

Server 2008 R2 includes Powershell V2, and hence modules are available.

It boils down to the following:

if (YourSystems are all Server 2008 R2) {
    Import the module and ignore the rest.
} elseif (One or more of the servers being managed is still on 2008 (original)) {
    Use the snapin.
}
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