Powershell script that sets your Internet Proxy settings and npm (if found) and auto-restarts Cntlm Authenication Proxy

posh-cntlm.ps1

#Requires -RunAsAdministrator
[CmdletBinding()]
param()

$ErrorActionPreference = "Stop"
trap
{
   Pop-Location
   Write-Error "$_"
   Exit 1
}

function Set-InternetProxy($proxyServer) {
    Write-Host "Setting proxy to be '$proxyServer' in Internet Settings" -ForegroundColor Cyan
    $internetSettings = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings"
    Set-ItemProperty -Path $internetSettings -Name ProxyServer -Value "$proxyServer"
    Set-ItemProperty -Path $internetSettings -Name ProxyEnable -Value 1

    # Set npm proxy
    if (Get-Command "npm.cmd" -ErrorAction SilentlyContinue) 
    { 
        Write-Host "Setting proxy to be '$proxyServer' for npm" -ForegroundColor Cyan
        npm config set proxy "http://$proxyServer"
        npm config set https-proxy "http://$proxyServer"
    }
}

function Clear-InternetProxy() {
    Write-Host "Clearing proxy server in Internet Settings"-ForegroundColor Yellow
    $internetSettings = "HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings"
    Set-ItemProperty -Path $internetSettings -Name ProxyServer -Value ""
    Set-ItemProperty -Path $internetSettings -Name ProxyEnable -Value 0

    # Clear npm proxy
    if (Get-Command "npm.cmd" -ErrorAction SilentlyContinue) 
    { 
        Write-Host "Clearing proxy server for npm" -ForegroundColor Yellow
        npm config delete proxy
        npm config delete https-proxy
    }
}

$eventId = "WatchCntlmWmi"
$watchCntlm = @{
    Query = "SELECT * FROM __InstanceModificationEvent WITHIN 1 WHERE targetInstance ISA 'win32_Service' AND targetInstance.Name='cntlm'"
    Action = {        
        Write-Host ("Service: '{0}' changed from '{2}' to '{3}'" -f $event.SourceEventArgs.NewEvent.TargetInstance.DisplayName,
                                                                    $event.SourceEventArgs.NewEvent.TargetInstance.Name,
                                                                    $event.SourceEventArgs.NewEvent.PreviousInstance.State,
                                                                    $event.SourceEventArgs.NewEvent.TargetInstance.State) -ForegroundColor Magenta

        if ($event.SourceEventArgs.NewEvent.TargetInstance.State -eq 'Stopped Pending') {
            try {
                $process = Get-Process cntlm -ErrorAction SilentlyContinue
                if ($process) {
                    Write-Host "Killing backing process 'Cntlm.exe'" -ForegroundColor Cyan
                    $process.Kill()
                }
            } catch {
                Write-Host "Failed to kill backing process 'Cntlm.exe' $_" -ForegroundColor Yellow
            }  
        }
        
        if ($event.SourceEventArgs.NewEvent.TargetInstance.State -eq 'Stopped') {
            try {
                Write-Host "Restarting 'Cntlm Authenication Proxy'" -ForegroundColor Cyan
                Start-Sleep 3
                $service = Get-Service -Name cntlm
                $service.Start()
            } catch {
                Write-Host "Failed to restart 'Cntlm Authenication Proxy' $_" -ForegroundColor Yellow
            }                                            
        }
    }
    SourceIdentifier = $eventId
}

$service = Get-Service -Name cntlm
try {
    Set-InternetProxy "localhost:3128"
    Register-WMIEvent @watchCntlm | Out-Null
    Write-Host "Monitoring 'Cntlm Authenication Proxy'" -ForegroundColor Cyan
    Write-Host "Start 'Cntlm Authenication Proxy' service" -ForegroundColor Green
    $service.Start()
    Wait-Event -SourceIdentifier $eventId
} catch {
    Write-Error $_
} finally {
    Clear-InternetProxy
    Write-Host "Stop monitoring 'Cntlm Authenication Proxy'" -ForegroundColor Red
    Unregister-Event -SourceIdentifier $eventId -Force -ErrorAction "Continue"
    Start-Sleep 3
    Write-Host "Stop 'Cntlm Authenication Proxy' service" -ForegroundColor Red
    $service.Stop()
    Write-Host "Bye :)" -ForegroundColor Blue
}