how-to-extend-pulsarctl-with-plugins.md

Extent pulsarctl with plugins

This guide demonstrates how to install and write extensions for pulsarctl.

Before you begin

You need to have a working pulsarctl binary installed. And the version of the pulsarctl need to be 0.4.0+.

Install pulsarctl plugins

A plugin is nothing more than a standalone executable file, whose name begins with pulsarctl-. To install a plugin, simply move its executable file to anywhere on your PATH.

Writing pulsarctl plugins

You can write a plugin in any programming language or script that allows you to write command-line commands.

There is no plugin installation or pre-loading required. Plugin executables receive the inherited environment from the plsarctl binary. A plugin determines which command path it wishes to implement based on its name. For example, a plugin wanting to provide a new command pulsarctl foo, would simply be named pulsarctl-foo, and live somewhere in your PATH.

Example plugin

#!/bin/bash

if [[ $1 == "args" ]]
then 
    echo "I am the args of the pulsarctl-foo"
    exit 0
fi

echo "I am a plugin named pulsarctl-foo"

Use a plugin

To use the above plugin, simply make it executable:

chmod +x ./pulsarctl-foo

and place it anywhere in your PATH:

mv pulsarctl-foo /usr/local/bin

You may now invoke your plugin as a kubectl command:

pulsarctl foo

I am a plugin named pulsarctl-foo

All args and flags are passed as-is to the executable:

pulsarctl foo args

I am the args of the pulsarctl-foo