skej

a simple event schedular for OpenFaaS

Skej allows you to declaratively schedule events for OpenFaaS functions.

How To

Prerequisites

Redis should be running on port 6379. This is easy to do with docker

docker run -d -p 6379:6379 redis

skej will try to autoconfigure redis to support expiring keys, but you may need to use redis-cli if it doesn't cooperate.

$ redis-cli
> config set notify-keyspace-events Ex

Install

$ npm install skej

Import skej

const skej = require('skej')

Write the schedule

Declare your schedule as a JSON object.

There are two types of scheduled functions single and pipe. One off and recurring functions would fall under single and can be scheduled like so.

// index.js
const schedule = {
	single: [
		{
			name: 'func_nodeinfo',
			initialRun: 5,
			onFinished: x => console.log(x.body)
		},
		{
			name: 'func_echoit',
			data: 'hello world',
			initialRun: 2,
			recurring: 10,
			onFinished: x => console.log(x.body)
		},
	],
}

Notice that the func_echoit function has an addition property, recurring. If the function should run more than once, at a regular interval, set the recurring flag to the appropriate duration in seconds. skej will handle the rest.

Adding a chain of functions requires grouping functions as pipe functions. Give the 'pipeline' a name, include and initial data that should be passed to the first function, and list the function names under pipeline

// index.js
  ...
	pipe: [
		{
			name: 'test',
			data: '',
			initialRun: 8,
			pipeline: [
				'func_nodeinfo',
				'func_wordcount'
			],
			onFinished: x => console.log(x.body)
		}
	]
}

// wrap schedule in the skej() function
skej(schedule)

See the example.js file for the completed description.

Launching

node index.js

ToDo

• Remove hardcoded gateway URL
• Ability to schedule to same function multiple times, name and function name should be seperate properties

Additional

Give it a try and please submit issues as you have them.