Summary

Provider-defined functions are now available in AWS, Google Cloud, and Kubernetes providers with Terraform 1.8. These custom functions enhance Terraform's capabilities and simplify complex tasks like ARN manipulation and Kubernetes manifest decoding. Users can now easily extend Terraform configurations using these new functions for diverse tasks.

Highlights

To access a provider-defined function, reference the provider:: namespace with the local name of the Terraform Provider. For example, you can use the direxists function by including provider::local::direxists() in your Terraform configuration. ([View Highlight] (https://read.readwise.io/read/01hv544brw8rew2wjg508bwz0j))

The Google Cloud provider also includes a new region_from_zone provider-defined function that helps obtain region names from a given zone (e.g. “us-west1” from “us-west1-a”). This simple string processing could be achieved in multiple ways using Terraform’s built-in functions previously, but the new function simplifies the process:
locals {
zone = “us-central1-a”

ways to derive the region “us-central1” using built-in functions

region_1 = join("-", slice(split("-", local.zone), 0, 2))
region_2 = substr(local.zone, 0, length(local.zone)-2)

our new region_from_zone function makes this easier!

region_3 = provider::google::region_from_zone(local.zone)
} ([View Highlight] (https://read.readwise.io/read/01hv544p54nqn66x34b9wsq8hx))