CloudCon 2025 - Implementing Custom rate limiting with Istio

This is a sample project demonstrating how to implement domain driven rate limiting with istio. The end goal is to setup rate limiting for an imaginary company called almost.ai...because it almost works :P

Infrastructure

Terraform for basic GKE cluster is available under /terraform

Kuberenetes manifests

All objects deployed to cluster are available under /manifests. As a prerequisite, the project requires istio to be installed, which can be done by running:

istioctl install --set profile=default -f istio-values.yaml -y

Rate limiting service

A sample application which is going to serve UI and also provide SToW rate limiting configuration is available under /ratelimiting-service It can be built and uploaded to the artifact repository.

DNS records

The configured network assumes the domain is almost.ai. This can be quickly done by adding two records to /etc/hosts with the external IP of an istio gateway. For example:

[external IP] api.almost.ai
[external IP] admin.almost.ai

The API server, which is a simple nginx server should be then available under the api domain, while the rate limiting service UI under admin.