mqtt-win-exec

An agent to execute commands in response to mqtt messages and publish result of command executions.

One example of use would be in a home automation scenario. You can install this tool on a Windows or linux machine and then control it centrally from Home Assistant or a similar software. You would also need a MQTT broker.

This tool only executes pre-defined set of commands. This is by design due to security considerations.

This was developed with Windows in mind as linux machines have more options from the get-go but it should run on any platform that is supported by nodejs. You would need to define proper command for your OS, of course.

Installation instructions

Have git and the node runtime installed (https://nodejs.org/). If you prefer not to install git you can download the zip and expand it manually.

git clone https://github.com/ayavilevich/mqtt-win-exec  
cd mqtt-win-exec  
npm i

Create a .env based on .env.sample.
Create a topics.json5 based on topics.sample.json5 and reference it in the .env.

node index.js

See that it works. Check that you are able to get and send mqtt messages. If all is correct, install as a service on Windows:

node windows-service-install.js

This will run the Windows 'net' command several times as an Administrator to add and configure the new service.

If you don't see the service appearing in the Windows Services screen, run uninstall and then install again from a command prompt running "as administrator".

TODO

None at this time

Troubleshooting

MQTT can be debugged per https://github.com/mqttjs/MQTT.js/blob/master/README.md#debug-logs , by setting the 'DEBUG' env var to 'mqttjs*'.

This can be set on a service by adding:

	env: [{
		name: "DEBUG",
		value: "mqttjs*",
	}],

to the windows-service-install.js script, then uninstalling and re-installing the service. Debug output of the service then goes to .\daemon\mqttwinexec.err.log .

Some useful powershell scripts that you can use with this executor

updates.ps1

$u = New-Object -ComObject Microsoft.Update.Session
$u.ClientApplicationID = 'MSDN Sample Script'
$s = $u.CreateUpdateSearcher()
$r = $s.Search("IsInstalled=0 and Type='Software' and IsHidden=0")
#$r = $s.Search('IsInstalled=0')
$r.updates|Select-Object -ExpandProperty Title

notification.ps1

param (
	[string]$notificationTitle = "Notification: " + [DateTime]::Now.ToShortTimeString()
)

$ErrorActionPreference = "Stop"

[Windows.UI.Notifications.ToastNotificationManager, Windows.UI.Notifications, ContentType = WindowsRuntime] > $null
$template = [Windows.UI.Notifications.ToastNotificationManager]::GetTemplateContent([Windows.UI.Notifications.ToastTemplateType]::ToastText01)

#Convert to .NET type for XML manipuration
$toastXml = [xml] $template.GetXml()
$toastXml.GetElementsByTagName("text").AppendChild($toastXml.CreateTextNode($notificationTitle)) > $null

#Convert back to WinRT type
$xml = New-Object Windows.Data.Xml.Dom.XmlDocument
$xml.LoadXml($toastXml.OuterXml)

$toast = [Windows.UI.Notifications.ToastNotification]::new($xml)
$toast.Tag = "PowerShell"
$toast.Group = "PowerShell"
$toast.ExpirationTime = [DateTimeOffset]::Now.AddSeconds(5)
#$toast.SuppressPopup = $true

$notifier = [Windows.UI.Notifications.ToastNotificationManager]::CreateToastNotifier("PowerShell")
$notifier.Show($toast);

Credits

Inspired by

https://gitlab.com/iotlink/iotlink
https://github.com/denschu/mqtt-exec
https://github.com/msiedlarek/winthing
https://github.com/jpmens/mqtt-launcher
https://github.com/rainu/mqtt-executor