Hi Everyone, new to prefect, looking for some pointers/guidance how to run PowerShell with prefect. I started looking at using the shell task but, I am not having much luck. My agent is running a Windows Server 2019. Thanks in advance.

Hi @Richard Hughes, sorry for the delay! I don't think the current

ShellTask

support PowerShell, unfortunately. This is a place we would really welcome contributors though!

@nicholas I looked at the code for the

ShellTask

and it looks similar to a `PowerShell`example I found on the web using the `POPEN`function. I think maybe some subtle difference in the code might make this available for different shells. Python is new for me so it will take some time if I have to write it.

No worries @Richard Hughes - can you describe what you're seeing? I'd like to open a ticket for this.

@nicholas let me get you some details

No worries at all @Richard Hughes - we'll be here 🙂

@nicholas I was able to write a flow with using PowerShell. I don't know if you want to create a PowerShell Task based upon this code or modify the shell task to accept PowerShell and handle it accordingly. Probably a separate task would be easier.

import os
import shlex
import sys
from prefect import task, Flow
from subprocess import Popen, PIPE
from prefect.triggers import all_successful, any_failed, some_successful

@task(name="PowerShell")
def sub_process_task(command):
    command=shlex.split(command)
    commandArray = ["powershell.exe"] + command
    p = Popen(commandArray, stdout=PIPE, stderr=PIPE)
    output, error = p.communicate()
    if p.returncode != 0: 
        raise Exception("powershell failed %d %s %s" % (p.returncode, output.decode("utf-8"), error.decode("utf-8")))
    else:
        #print("powershell succeeded %d %s" % (p.returncode, output.decode("utf-8")))
        return output.decode("utf-8")

@task(name="Print", trigger=all_successful)
def output_handler(output):
    print('Finished Running the flow')
    print(output)
    print('Finished Printing the flow')

with Flow('PowerShell') as flow:
    command="Write-Host 'Hello World'; Write-Host 'Test12345'; Get-Location; Get-ChildItem -Dir;"
    output=sub_process_task(command=command)
    output_handler(output)

flow.run()

Hi @Richard Hughes, this looks great! Could I encourage you to open a ticket or even a PR with this code? The Core folks will have stronger opinions on how this could/should be structured