Overview

Functions are the foundation of Greenlight’s engine that allows for load balancing and other user-defined behavior. One or more Functions is used within a Resource Record.

Every Function “returns” some kind of data, much like in a programming language. Depending on the context, this could be some DNS data (e.g. an IPv6 address/AAAA record), or something else like a boolean value (e.g. a Connection Check).

Functions that return booleans and actively monitor some external condition are called “Checks,”¹ since it’s these functions that will be used to perform healthchecking.

Some functions take other functions as inputs, e.g. Conditionals.

Other functions take simple, static values, e.g. Constants.

Footnotes

1. This “check” terminology is used in Greenlight’s Prometheus metrics. ↩