simple-rl-for-api-owners.md

Simple Rate Limit For API Owners

This user guide shows how to configure rate limiting for one of the subdomains.

Clone the project

git clone https://github.com/Kuadrant/kuadrant-controller

Setup environment

This step creates a containerized Kubernetes server locally using Kind, then it installs Istio, Kubernetes Gateway API and kuadrant.

make local-setup

Deploy toystore example deployment

kubectl apply -f examples/toystore/toystore.yaml

Create HTTPRoute to configure routing to the toystore service

kubectl apply -f - <<EOF
---
apiVersion: gateway.networking.k8s.io/v1alpha2
kind: HTTPRoute
metadata:
  name: toystore
  labels:
    app: toystore
spec:
  parentRefs:
    - name: istio-ingressgateway
      namespace: istio-system
  hostnames: ["*.toystore.com"]
  rules:
    - matches:
        - path:
            type: PathPrefix
            value: "/toy"
          method: GET
      backendRefs:
        - name: toystore
          port: 80
EOF

Check toystore HTTPRoute works

curl -v -H 'Host: api.toystore.com' http://localhost:9080/toy

It should return 200 OK.

Note: This only works out of the box on linux environments. If not on linux, you may need to forward ports

kubectl port-forward -n kuadrant-system service/kuadrant-gateway 9080:80

Create RateLimitPolicy for ratelimiting only for specific subdomain

RateLimitPolicy applied for the toystore HTTPRoute.

Hostname	Rate Limits
rate-limited.toystore.com	5 reqs / 10 secs (0.5 rps)
*.toystore.com	not rate limited

kubectl apply -f - <<EOF
---
apiVersion: apim.kuadrant.io/v1alpha1
kind: RateLimitPolicy
metadata:
  name: toystore
spec:
  targetRef:
    group: gateway.networking.k8s.io
    kind: HTTPRoute
    name: toystore
  rateLimits:
    - rules:
        - hosts: ["rate-limited.toystore.com"]
      configurations:
        - actions:
            - generic_key:
                descriptor_key: "limited"
                descriptor_value: "1"
      limits:
        - conditions:
            - "limited == 1"
          maxValue: 5
          seconds: 10
          variables: []
EOF

Validating the rate limit policy

Only 5 requests every 10 secs on rate-limited.toystore.com allowed.

curl -v -H 'Host: rate-limited.toystore.com' http://localhost:9080/toy

Whereas other.toystore.com is not rate limited.

curl -v -H 'Host: other.toystore.com' http://localhost:9080/toy