Gateway Observability

Envoy Gateway provides observability for the ControlPlane and the underlying EnvoyProxy instances. This task show you how to config gateway control-plane observability, includes metrics.

Prerequisites

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

Envoy Gateway provides an add-ons Helm Chart, which includes all the needing components for observability. By default, the OpenTelemetry Collector is disabled.

Install the add-ons Helm Chart:

helm install eg-addons oci://docker.io/envoyproxy/gateway-addons-helm --version v0.0.0-latest --set opentelemetry-collector.enabled=true -n monitoring --create-namespace

Metrics

The default installation of Envoy Gateway installs a default EnvoyGateway configuration and attaches it using a ConfigMap. In this section, we will update this resource to enable various ways to retrieve metrics from Envoy Gateway.

Retrieve Prometheus Metrics from Envoy Gateway

By default, prometheus metric is enabled. You can directly retrieve metrics from Envoy Gateway:

export ENVOY_POD_NAME=$(kubectl get pod -n envoy-gateway-system --selector=control-plane=envoy-gateway,app.kubernetes.io/instance=eg -o jsonpath='{.items[0].metadata.name}')
kubectl port-forward pod/$ENVOY_POD_NAME -n envoy-gateway-system 19001:19001

# check metrics 
curl localhost:19001/metrics

The following is an example to disable prometheus metric for Envoy Gateway.

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
    telemetry:
      metrics:
        prometheus:
          disable: true
EOF

Save and apply the following resource to your cluster:

---
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
    telemetry:
      metrics:
        prometheus:
          disable: true    

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

Enable Open Telemetry sink in Envoy Gateway

The following is an example to send metric via Open Telemetry sink to OTEL gRPC Collector.

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
    telemetry:
      metrics:
        sinks:
          - type: OpenTelemetry
            openTelemetry:
              host: otel-collector.monitoring.svc.cluster.local
              port: 4317
              protocol: grpc
EOF

Save and apply the following resource to your cluster:

---
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
    telemetry:
      metrics:
        sinks:
          - type: OpenTelemetry
            openTelemetry:
              host: otel-collector.monitoring.svc.cluster.local
              port: 4317
              protocol: grpc    

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

Verify OTel-Collector metrics:

export OTEL_POD_NAME=$(kubectl get pod -n monitoring --selector=app.kubernetes.io/name=opentelemetry-collector -o jsonpath='{.items[0].metadata.name}')
kubectl port-forward pod/$OTEL_POD_NAME -n monitoring 19001:19001

# check metrics 
curl localhost:19001/metrics