This article applies as of PRTG 26.x.119

Introduction

The following script allows you to execute SSH script using an EXE/Script sensor. It will connect to the server, execute the given command and simply return the output to the sensor. That given, it can be used for either EXE/Script, EXE/Script (Advanced) or a EXE notification.

Please have a look at our guide for installing PowerShell based sensors for installation details.

Note: The script is provided as is and may or may not work with your installation.

Requirements

1. Configured Windows credentials in the given host
2. Configured Linux credentials in the given host
3. Security context of the sensor is set to Use Windows credentials of parent device

Parameters

You can replace some parameters with PRTG-supported placeholders. Use caution when using placeholders for credentials. If you use a placeholder in an error message or sensor message, PRTG resolves the placeholder before displaying the output. This might expose your credentials in plain text.

Version History

Script

# ___ ___ _____ ___
#| _ \ _ \_   _/ __|
#|  _/   / | || (_ |
#|_| |_|_\ |_| \___|
#    NETWORK MONITOR
#-------------------
# Description: This sensor will use Posh-SSH to connect to the server
# Parameters:
# -Computername:    The linux host you want to connect to
# -Username         Your linux username
# -Password         Your linux password
# -Command          The command to execute on your host,
# -AutoUpdateFingerPrint   Set this to when calling the script to automatically update the SSH fingerprints of known devices. 
# Careful, though!
#
##########
#
# Version History
# ----------------------------
# Version Date        Description 
# 1.1     29/12/2016  [Fixed]    Updated session handling
#                     [Improved] Posh-SSH is now automatically installed 
#                     [Fixed]    AutoUpdateFingerPrint works correctly now  
# 1.0     05/2015  Initial Release 
#
# (c) 2015 Stephan Linke | Paessler AG
 
# Parameters
param(  
    $Computername = "",
    $Username = "",
    $Password = "",
    $Port = 22,
    $KeyfilePath = "",
    $Command = "echo '0:Hello World'",
    $AutoUpdateFingerprint = $False
)
 
# Check if our module loaded properly
if (Get-Module -ListAvailable -Name Posh-SSH) { <# do nothing #> }
else { 
    # install the module automatically
    iex (New-Object Net.WebClient).DownloadString("https://gist.github.com/darkoperator/6152630/raw/c67de4f7cd780ba367cccbc2593f38d18ce6df89/instposhsshdev")
 }
 
function This-FingerPrintUpdate(){
    if($AutoUpdateFingerprint)
    { Remove-SSHTrustedHost $Computername }
}
 
# Includes
Import-Module Posh-SSH
 
 
function This-GetSSHCommandOutput(){
	# Create new session and execute the command given
    if($keyfilePath.Length -eq 0){
 
        # Generate credentials object for authentication
	 $nopasswd = New-Object System.Security.SecureString
        $Credential = New-Object System.Management.Automation.PSCredential ($Username, $nopasswd)	
        $Session = New-SSHSession -Computername $Computername -Credential $Credential -Acceptkey -KeyFile $keyfilePath -Port $Port

    }
    else
    { $Session = New-SSHSession -Computername $Computername -Acceptkey $true -KeyFile $keyfilePath -Port $Port }
	
    # Store the output of the command 
    $Output = (Invoke-SSHCommand -SSHSession $Session -Command $Command).Output
	
    # Remove the session after we're done
    Remove-SSHSession -Name $Session | Out-Null 
	
    # return the actual output
    Write-Host $Output.Trim();
 
}

# Automatically update the fingerprint for the given host. 
This-FingerPrintUpdate;

# echo the output to PRTG 
This-GetSSHCommandOutput;

Notes

The %linuxuser placeholder can't be used for notifications. Instead, use a keyfile for authentication. Otherwise, you'll have to use clear text passwords within the parameters of the notification, which is not safe of course :)