A collection of simple Lua modules for writing Webscript.io webhooks. They can be imported directly on Webscript.io using the module name. For example:

local tokeniser = require('Pathoschild/webscript-helpers/tokeniser')

This is an early experiment for my own use; it has few features and may change at any time.

Tokeniser

This module extracts tokens from arbitrary text. It's mainly intended for webhooks that need to parse text payloads.

For example, Amazon Web Services sends alert emails that look like this:

AWS Elastic Beanstalk Notification - New application version was deployed to running EC2 instances

Timestamp: Fri Oct 16 15:40:00 UTC 2015
Message: New application version was deployed to running EC2 instances.
Environment: sample-api-edge
Application: sample-api
Environment URL: http://sample-api-edge.elasticbeanstalk.com

This module lets you tokenise simple strings like the subject:

local service, subject = tokeniser.capture(payload.subject, "^AWS ([^-]+) Notification - (.+)")

Or tokenise complex strings:

local tokens = {}
tokeniser.parse(tokens, payload.body, {
   timestamp = "Timestamp: ([^\r\n]+)",
   message = "Message: ([^\r\n]+)",
   environment = "Environment: ([^\r\n]+)",
   environmentUrl = "Environment URL: ([^\r\n]+)",
   application = "Application: ([^\r\n]+)"
})

(See docstrings in the Lua file for details.)

Slack

This module provides a minimal Slack client for using an 'Incoming WebHooks' integration configured via Slack.

Basic usage:

local client = slack.getClient('https://incoming-webhook-url')
client.post('Hi there!')

You can also customise the display name, avatar URL, and channel. (See docstrings in the Lua file for details.)

Error monitoring

This module provides utilities for error-monitoring webhooks on Webscript.io.

The most basic usage sends an email alert to the webhook owner when an error occurs:

return monitoring.get('AWS event', request).monitor(function()
	-- webhook code goes here
end)

You can also specify error handlers, which are just functions that accept three arguments (error, request, webhook name), and return true (handled) or false (not handled). For example, this code notifies a Slack channel when a webhook throws an error:

monitoring.get('AWS event', request, {monitoring.getSlackNotifier(slack)}).monitor(function()
	-- webhook code goes here
end)

(See docstrings in the Lua file for details.)