Accessing ZeroMQ from Windows PowerShell


In one of the project, we wanted to write logs from Windows PowerShell script to our central logging server when script is executed to update the packages and restart the windows service.   

On server side, we implemented ZeroMQ Server (C#) which pulls data from multiple processes and write to the log file using NLog.   

On client side, I used Windows PowerShell accessing ZeroMQ push socket to push the messages.

Window PowerShell support loading and accessing functionality from any CLR assemblies. 

To load the assembly, you need to use LoadFile function.
[System.Reflection.Assembly]::LoadFile("C:\zmqclr\bin\clrzmq.dll");.


To create the ZeroMQ Context which is a static function,
 [ZeroMQ.ZmqContext]::Create()


To create a socket (push) from Zmq Context
([ZeroMQ.ZmqSocket]$zmqCtx.CreateSocket([ZeroMQ.SocketType]::PUSH));


And now connect to the central logging server on port 10000
zmqSocket.Connect("tcp://localhost:10000");


Once Socket is connected, you can send messages using send function.
zmqSocket.Send($data, $data.Length, [ZeroMQ.SocketFlags]::None)

Below is the script.

#=======================================================================
# Purpose: Send logs to logging server using ZeroMQ
# Author: Rohit Joshi
# Date: 10/31/2012
#=======================================================================
#Global variables
$global:zmqSocket=$null
$enc = [system.Text.Encoding]::Unicode

#=======================================================================
# Function: Init ZeroMQ
# Arguments:
#=======================================================================
# Purpose: Initialize the zeromq
#=======================================================================
Function InitZeroMQ()
{

  $zmqCtx= [ZeroMQ.ZmqContext]::Create()
  $global:zmqSocket =([ZeroMQ.ZmqSocket]$zmqCtx.CreateSocket([ZeroMQ.SocketType]::PUSH));
  $global:zmqSocket.SendHighWatermark = 5000;
  $global:zmqSocket.Connect("tcp://localhost:10000");
}

#=======================================================================
# Function: SendMessage
# Arguments: string 
#=======================================================================
# Purpose:Send Message
#=======================================================================
Function SendMessage($msg)
{
 $data=$enc.GetBytes($msg) 
 $global:zmqSocket.Send($data, $data.Length, [ZeroMQ.SocketFlags]::None)
}

InitZeroMQ();
SendMessage("Sending data from PowerShell script");



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