RateLimit Observability

Envoy Gateway provides observability for the RateLimit instances. This guide show you how to config RateLimit observability, includes traces.

Prerequisites

Follow the steps from the Quickstart Guide to install Envoy Gateway and the HTTPRoute example manifest. Before proceeding, you should be able to query the example backend using HTTP. Follow the steps from the Global Rate Limit to install RateLimit.

OpenTelemetry Collector offers a vendor-agnostic implementation of how to receive, process and export telemetry data.

Install OTel-Collector:

helm repo add open-telemetry https://open-telemetry.github.io/opentelemetry-helm-charts
helm repo update
helm upgrade --install otel-collector open-telemetry/opentelemetry-collector -f https://raw.githubusercontent.com/envoyproxy/gateway/latest/examples/otel-collector/helm-values.yaml -n monitoring --create-namespace --version 0.60.0

Traces

By default, the Envoy Gateway does not configure RateLimit to send traces to the OpenTelemetry Sink. You can configure the collector in the rateLimit.telemetry.tracing of the EnvoyGatewayCRD.

RateLimit uses the OpenTelemetry Exporter to export traces to the collector. You can configure a collector that supports the OTLP protocol, which includes but is not limited to: OpenTelemetry Collector, Jaeger, Zipkin, and so on.

Note:

• By default, the Envoy Gateway configures a 100% sampling rate for RateLimit, which may lead to performance issues.

Assuming the OpenTelemetry Collector is running in the observability namespace, and it has a service named otel-svc, we only want to sample 50% of the trace data. We would configure it as follows:

• Apply from stdin
• Apply from file

cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: ConfigMap
metadata:
  name: envoy-gateway-config
  namespace: envoy-gateway-system
data:
  envoy-gateway.yaml: |
    apiVersion: gateway.envoyproxy.io/v1alpha1
    kind: EnvoyGateway
    provider:
      type: Kubernetes
    gateway:
      controllerName: gateway.envoyproxy.io/gatewayclass-controller
    rateLimit:
      backend:
        type: Redis
        redis:
          url: redis-service.default.svc.cluster.local:6379
      telemetry:
        tracing:
          sampleRate: 50
          provider:
            url: otel-svc.observability.svc.cluster.local:4318
EOF

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: envoy-gateway-config
  namespace: envoy-gateway-system
data:
  envoy-gateway.yaml: |
    apiVersion: gateway.envoyproxy.io/v1alpha1
    kind: EnvoyGateway
    provider:
      type: Kubernetes
    gateway:
      controllerName: gateway.envoyproxy.io/gatewayclass-controller
    rateLimit:
      backend:
        type: Redis
        redis:
          url: redis-service.default.svc.cluster.local:6379
      telemetry:
        tracing:
          sampleRate: 50
          provider:
            url: otel-svc.observability.svc.cluster.local:4318    

After updating the ConfigMap, you will need to restart the envoy-gateway deployment so the configuration kicks in:

kubectl rollout restart deployment envoy-gateway -n envoy-gateway-system