Gateway API Metrics

  3 minute read  

Resource metrics for Gateway API objects are available using the Gateway API State Metrics project. The project also provides example dashboard for visualising the metrics using Grafana, and example alerts using Prometheus & Alertmanager.

Prerequisites

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

Expand for instructions

  1. Install the Gateway API CRDs and Envoy Gateway using Helm:

    helm install eg oci://docker.io/envoyproxy/gateway-helm --version v0.0.0-latest -n envoy-gateway-system --create-namespace

  2. Install the GatewayClass, Gateway, HTTPRoute and example app:

    kubectl apply -f https://github.com/envoyproxy/gateway/releases/download/latest/quickstart.yaml -n default

  3. Verify Connectivity:

    You can also test the same functionality by sending traffic to the External IP. To get the external IP of the Envoy service, run:

    export GATEWAY_HOST=$(kubectl get gateway/eg -o jsonpath='{.status.addresses[0].value}')

    Note: In certain environments, the load balancer may be exposed using a hostname, instead of an IP address. If so, replace ip in the above command with hostname.

    Curl the example app through Envoy proxy:

    curl --verbose --header "Host: www.example.com" http://$GATEWAY_HOST/get

    Get the name of the Envoy service created by the example Gateway:

    export ENVOY_SERVICE=$(kubectl get svc -n envoy-gateway-system --selector=gateway.envoyproxy.io/owning-gateway-namespace=default,gateway.envoyproxy.io/owning-gateway-name=eg -o jsonpath='{.items[0].metadata.name}')

    Port forward to the Envoy service:

    kubectl -n envoy-gateway-system port-forward service/${ENVOY_SERVICE} 8888:80 &

    Curl the example app through Envoy proxy:

    curl --verbose --header "Host: www.example.com" http://localhost:8888/get

Run the following commands to install the metrics stack, with the Gateway API State Metrics configuration, on your kubernetes cluster:

kubectl apply --server-side -f https://raw.githubusercontent.com/Kuadrant/gateway-api-state-metrics/main/config/examples/kube-prometheus/bundle_crd.yaml
kubectl apply -f https://raw.githubusercontent.com/Kuadrant/gateway-api-state-metrics/main/config/examples/kube-prometheus/bundle.yaml

Metrics and Alerts

To access the Prometheus UI, wait for the statefulset to be ready, then use the port-forward command:

# This first command may fail if the statefulset has not been created yet.
# In that case, try again until you get a message like 'Waiting for 2 pods to be ready...'
# or 'statefulset rolling update complete 2 pods...'
kubectl -n monitoring rollout status --watch --timeout=5m statefulset/prometheus-k8s
kubectl -n monitoring port-forward service/prometheus-k8s 9090:9090 > /dev/null &

Navigate to http://localhost:9090. Metrics can be queried from the ‘Graph’ tab e.g. gatewayapi_gateway_created See the Gateway API State Metrics README for the full list of Gateway API metrics available.

Alerts can be seen in the ‘Alerts’ tab. Gateway API specific alerts will be grouped under the ‘gateway-api.rules’ heading.

Note: Alerts are defined in a PrometheusRules custom resource in the ‘monitoring’ namespace. You can modify the alert rules by updating this resource.

Dashboards

To view the dashboards in Grafana, wait for the deployment to be ready, then use the port-forward command:

kubectl -n monitoring wait --timeout=5m deployment/grafana --for=condition=Available
kubectl -n monitoring port-forward service/grafana 3000:3000 > /dev/null &

Navigate to http://localhost:3000 and sign in with admin/admin. The Gateway API State dashboards will be available in the ‘Default’ folder and tagged with ‘gateway-api’. See the Gateway API State Metrics README for further information on available dashboards.

Note: Dashboards are loaded from configmaps. You can modify the dashboards in the Grafana UI, however you will need to export them from the UI and update the json in the configmaps to persist changes.


Last modified February 21, 2025: feat: support HPA in helm chart (#5127) (57c7e64)