istio.io/content/en/docs/tasks/observability/metrics/customize-metrics/index.md

title	description	weight	keywords	owner	test
Customizing Istio Metrics	This task shows you how to customize the Istio metrics.	25	telemetry metrics customize	istio/wg-policies-and-telemetry-maintainers	yes

This task shows you how to customize the metrics that Istio generates.

Istio generates telemetry that various dashboards consume to help you visualize your mesh. For example, dashboards that support Istio include:

• Grafana
• Kiali
• Prometheus

By default, Istio defines and generates a set of standard metrics (e.g. requests_total), but you can also customize them and create new metrics using the Telemetry API.

Before you begin

Install Istio in your cluster and deploy an application. Alternatively, you can set up custom statistics as part of the Istio installation.

The Bookinfo sample application is used as the example application throughout this task. For installation instructions, see deploying the Bookinfo application.

Enable custom metrics

To customize telemetry v2 metrics, for example, to add request_host and destination_port dimensions to the requests_total metric emitted by both gateways and sidecars in the inbound and outbound direction, use the following:

{{< text bash >}} $ cat < ./custom_metrics.yaml apiVersion: telemetry.istio.io/v1alpha1 kind: Telemetry metadata: name: namespace-metrics spec: metrics:

• providers:
  • name: prometheus overrides:
  • match: metric: REQUEST_COUNT tagOverrides: destination_port: value: "string(destination.port)" request_host: value: "request.host" EOF $ kubectl apply -f custom_metrics.yaml {{< /text >}}

Verify the results

Send traffic to the mesh. For the Bookinfo sample, visit http://$GATEWAY_URL/productpage in your web browser or issue the following command:

{{< text bash >}} $ curl "http://$GATEWAY_URL/productpage" {{< /text >}}

{{< tip >}} $GATEWAY_URL is the value set in the Bookinfo example. {{< /tip >}}

Use the following command to verify that Istio generates the data for your new or modified dimensions:

{{< text bash >}} kubectl exec "(kubectl get pod -l app=productpage -o jsonpath='{.items[0].metadata.name}')" -c istio-proxy -- curl -sS 'localhost:15000/stats/prometheus' | grep istio_requests_total {{< /text >}}

For example, in the output, locate the metric istio_requests_total and verify it contains your new dimension.

{{< tip >}} It might take a short period of time for the proxies to start applying the config. If the metric is not received, you may retry sending requests after a short wait, and look for the metric again. {{< /tip >}}

Use expressions for values

The values in the metric configuration are common expressions, which means you must double-quote strings in JSON, e.g. "'string value'". Unlike Mixer expression language, there is no support for the pipe (|) operator, but you can emulate it with the has or in operator, for example:

{{< text plain >}} has(request.host) ? request.host : "unknown" {{< /text >}}

For more information, see Common Expression Language.

Istio exposes all standard Envoy attributes. Peer metadata is available as attributes upstream_peer for outbound and downstream_peer for inbound with the following fields:

Field	Type	Value
name	string	Name of the pod.
namespace	string	Namespace that the pod runs in.
labels	map	Workload labels.
owner	string	Workload owner.
workload_name	string	Workload name.
platform_metadata	map	Platform metadata with prefixed keys.
istio_version	string	Version identifier for the proxy.
mesh_id	string	Unique identifier for the mesh.
app_containers	list<string>	List of short names for application containers.
cluster_id	string	Identifier for the cluster to which this workload belongs.

For example, the expression for the peer app label to be used in an outbound configuration is upstream_peer.labels['app'].value.

Cleanup

To delete the Bookinfo sample application and its configuration, see Bookinfo cleanup.