psytricks 1.0.0

PowerShell Python Citrix Tricks.

PSytricks

PowerShell Python Citrix Tricks.

Pun intended.

This package provides an abstraction layer allowing Python code to interact with a Citrix Virtual Apps and Desktops (CVAD) stack, i.e. to fetch status information and trigger actions on machines and sessions. It does this by calling a wrapper script written in Windows PowerShell (note: not PowerShell Core, see below) that is using the Citrix Broker PowerShell Snap-In which is provided along with the Delivery Controller installation media.

🤯 Are you serious?

Calling PowerShell as a subprocess from within Python? 😳

To convert results to JSON and pass them back, just to parse it again in Python. Really? 🧐

✅ Yes. We. Are

And the package name was chosen to reflect this.

To be very clear: performance is abysmal, but this is not at all an issue for us. Abysmal, as in: for every wrapped call a full (new) PowerShell process needs to be instantiated, usually taking something like 1-2 seconds. ⏱

However, the frequency of calls is also very low in our use case - not more than a handful per minute, and that's already the peak. Therefore, having a robust way of interacting with the Citrix platform outnumbers all other arguments. 🍹

Installation

Prerequisites

As mentioned above, the Citrix Broker PowerShell Snap-In is required to be installed on the machine that will run the wrapper script, since its commands are being used to communicate with the CVAD stack. This is also the reason why this package will work on Windows PowerShell only as snap-ins are not supported on other PowerShell editions. Please note this also implies that the latest usable PowerShell version is 5.1 as newer ones have dropped support for snap-ins (but that's a different problem that Citrix will have to solve at some point).

To install the snap-in, look for an MSI package like this in the Delivery Controller or XenDesktop installation media and install it as usual:

• Broker_PowerShellSnapIn_x64.msi

Installing the package

For installing psytricks please create a venv, then run:

pip install psytricks

This will also register the CLI tool psytricks.exe although that one is mostly meant for testing and demonstration purposes, otherwise the *-Broker* commands provided by the PowerShell snap-in could be used directly.

What does it provide?

To interact with CVAD, a psytricks.wrapper.PSyTricksWrapper object needs to be instantiated and passed the address of the Delivery Controller to connect to, for example:

from psytricks.wrapper import PSyTricksWrapper

wrapper = PSyTricksWrapper(deliverycontroller="cdc01.vdi.example.xy")

Fetching status information

The wrapper object can then be used to e.g. retrieve information on the machines controlled ("brokered") by Citrix:

machines = wrapper.get_machine_status()

for machine in machines:
    print(f"[{machine["DNSName"]}] is in power state '{machine["PowerState"]}'")
print(f"Got status details on {len(machines)} machines.")

Performing actions

To restart a machine, use something like this:

wrapper.perform_poweraction(machine="vm23.vdi.example.xy", action="restart")

For placing a machine in Maintenance Mode use:

wrapper.set_maintenance(machine="vm42.vdi.example.xy", disable=False)