PM2 as a Windows Service under Local Service

README.md

PM2 as a Windows Service under Local Service

Written for jon-hall/pm2-windows-service#3

This is a PoC for running PM2 as a Windows Service under the Local Service account instead of the Local System account.

Prerequsites

• Neither pm2 or pm2-windows-service installed yet. (The Powershell script will run npm i)
  • At the very least, you should run pm2-service-uninstall before running this script
• npm and npm-cache global folders should be somewhere accessible to NT AUTHORITY\LocalService.
  • Instructions for moving them to C:\ProgramData\

Use

• Copy install.ps1 to the root of your node app

• From an Elevated Powershell prompt run: .\install.ps1 -Pm2Home "C:\etc\.pm2" -AppStart "[path to node app start]"

• Your Node app should be running under PM2. pm2 monit should show processes running.

install.ps1

# Deploys application as an app within a PM2 service
# Run from root of Node application

param(
	[string] $Pm2Home = $env:PM2_HOME,
	[string] $AppStart = "app.js"
)

$ErrorActionPreference = "Stop"

function Install-Node-Modules
{
	Write-Host "Running npm install"
	& "npm" i
}

function Create-Pm2-Home
{
	Write-Host "Attempting to create $Pm2Home and give FullControl to LOCAL SERVICE"
	New-Item -ItemType Directory -Force -Path $Pm2Home

	$rule = New-Object System.Security.AccessControl.FileSystemAccessRule(
		"LOCAL SERVICE", "FullControl", "ContainerInherit, ObjectInherit",
		"None", "Allow")

	try {
	  $acl = Get-Acl -Path $Pm2Home -ErrorAction Stop
		$acl.SetAccessRule($rule)
		Set-Acl -Path $Pm2Home -AclObject $acl -ErrorAction Stop
		Write-Host "Successfully set FullControl permissions on $Pm2Home"
	} catch {
		throw "$Pm2Home : Failed to set permissions. Details : $_"
	}
}

function Install-Pm2-Service
{
	Write-Host "Installing pm2"
	& "npm" i "pm2@latest" "-g"
	Write-Host "Installing pm2-windows-service npm module"
	& "npm" i pm2-windows-service "-g"
	& "pm2-service-install"
	
	# Create wrapper log file, otherwise it won't start
	$wrapperLogPath = "$(npm config get prefix)\node_modules\pm2-windows-service\src\daemon\pm2.wrapper.log"
	
	if (Test-Path $wrapperLogPath) {
		Write-Debug "PM2 service wrapper log file already exists"
	} else {
		Out-File $wrapperLogPath -Encoding utf8
	}
}

function Create-Pm2-Service-Config
{
	param([string] $ConfigPath, [string] $CmdPath)

	$configContent = @"
{
	"apps": [{
		"name": "node-app",
		"script": "$($CmdPath -replace "\\","\\")",
		"args": [],
		"cwd": "$((Split-Path $CmdPath) -replace "\\","\\")",
		"merge_logs": true,
		"instances": 4,
		"exec_mode": "cluster_mode",
		"env": {
			"NODE_ENV": "development"
		}
	}]
}
"@

	# Write out config to JSON file
	Write-Host "Writing PM2 service configuration to $ConfigPath"
	$configContent | Out-File $ConfigPath -Encoding utf8
}

# From http://stackoverflow.com/a/4370900/964356
function Set-ServiceAcctCreds
{
	param([string] $serviceName, [string] $newAcct, [string] $newPass)

	$filter = "Name='$serviceName'"

	$tries = 0
	
	while (($service -eq $null -and $tries -le 3)) {
		if ($tries -ne 0) {
			sleep 2
		}
		$service = Get-WMIObject -namespace "root\cimv2" -class Win32_Service -Filter $filter
		$tries = $tries + 1
	}

	if ($service -eq $null) {
		throw "Could not find '$serviceName' service"
	}

	$service.Change($null,$null,$null,$null,$null,$null,$newAcct,$newPass)

	$service.StopService()

	while ($service.Started) {
		sleep 2
		$service = Get-WMIObject -namespace "root\cimv2" -class Win32_Service -Filter $filter
	}
	$service.StartService()
}

function Change-Pm2-Service-Account
{
	Write-Host "Changing PM2 to run as LOCAL SERVICE"
	Set-ServiceAcctCreds -serviceName "pm2.exe" -newAcct "NT AUTHORITY\LocalService" -newPass ""
}

$env:PM2_HOME = $Pm2Home
$env:PM2_SERVICE_SCRIPTS = "$Pm2Home\ecosystem.json"

[Environment]::SetEnvironmentVariable("PM2_HOME", $env:PM2_HOME, "Machine")
[Environment]::SetEnvironmentVariable("PM2_SERVICE_SCRIPTS", $env:PM2_SERVICE_SCRIPTS, "Machine")

& Install-Node-Modules
& Create-Pm2-Home
& Create-Pm2-Service-Config -ConfigPath $env:PM2_SERVICE_SCRIPTS -CmdPath $AppStart
& Install-Pm2-Service
& Change-Pm2-Service-Account

Here is an alternate way of going about it:
https://gist.github.com/zubair1024/8f6126db7ffbafd706f0e328ef8d4662

This is fantastic, thank you @maxfierke!

I adapted @mauron85's version of this script into a standalone installer, with a few additions:

• Optionally automate migrating npm and npm-cache folders to C:\ProgramData\
• Enable offline installation by caching packages on a build machine
• Query for the Local Service user by its security identifier to better support non-English Windows installations

Hopefully this is helpful to someone: https://github.com/jessety/pm2-installer