MeshMetric

This policy uses new policy matching algorithm. Do not combine with Traffic Metrics.

Kuma facilitates consistent traffic metrics across all data plane proxies in your mesh.

You can define metrics configuration for a whole Mesh, and optionally tweak certain parts for individual data plane proxies. For example, you might need to override the default metrics port if it’s already in use on the specified machine.

Kuma provides full integration with Prometheus:

  • Each proxy can expose its metrics in Prometheus format.
  • Kuma exposes an API called the monitoring assignment service (MADS) which exposes proxies configured by MeshMetric.

Moreover, Kuma provides experimental integration with OpenTelemetry:

To collect metrics from Kuma, you need to expose metrics from proxies and applications.

In the rest of this page we assume you have already configured your observability tools to work with Kuma. If you haven’t already read the observability docs.

TargetRef support matrix

targetRefAllowed kinds
targetRef.kindMesh, MeshSubset, MeshService, MeshServiceSubset
targetRefAllowed kinds
targetRef.kindMesh, MeshGateway, MeshGateway with listener tags
targetRefAllowed kinds
targetRef.kindMesh, MeshSubset, MeshService, MeshServiceSubset

To learn more about the information in this table, see the matching docs.

Configuration

There are three main sections of the configuration: sidecar, applications, backends. The first two define how to scrape parts of the mesh (sidecar and underlying applications), the third one defines what to do with the data (in case of Prometheus instructs to scrape specific address, in case of OpenTelemetry defines where to push data).

In contrast to Traffic Metrics all configuration is dynamic and no restarts of the Data Plane Proxies are needed. You can define configuration refresh interval by using KUMA_DATAPLANE_RUNTIME_DYNAMIC_CONFIGURATION_REFRESH_INTERVAL env var or dataplaneRuntime.dynamicConfiguration.refreshInterval Helm value.

Sidecar

This part of the configuration applies to the data plane proxy scraping. In case you don’t want to retrieve all Envoy’s metrics, it’s possible to filter them.

Regex

You are able to specify regex which causes the metrics endpoint to return only matching metrics.

Unused metrics

By default, metrics that were not updated won’t be published. You can set the includeUnused flag that returns all metrics from Envoy.

Examples

Include unused metrics and filter them by regex
  1. apiVersion: kuma.io/v1alpha1
  2. kind: MeshMetric
  3. metadata:
  4.   name: metrics-default
  5.   namespace: kuma-system
  6.   labels:
  7.     kuma.io/mesh: default
  8. spec:
  9.   targetRef:
  10.     kind: Mesh
  11.   default:
  12.     sidecar:
  13.       regex: http2_act.*
  14.       includeUnused: true
  15.     backends:
  16.     - type: Prometheus
  17.       prometheus:
  18.         port: 5670
  19.         path: "/metrics"
  1. type: MeshMetric
  2. mesh: default
  3. name: metrics-default
  4. spec:
  5.   targetRef:
  6.     kind: Mesh
  7.   default:
  8.     sidecar:
  9.       regex: http2_act.*
  10.       includeUnused: true
  11.     backends:
  12.     - type: Prometheus
  13.       prometheus:
  14.         port: 5670
  15.         path: "/metrics"

Applications

In addition to exposing metrics from the data plane proxies, you might want to expose metrics from applications running next to the proxies. Kuma allows scraping Prometheus metrics from the applications endpoint running in the same Pod or VM. Later those metrics are aggregated and exposed at the same port/path as data plane proxy metrics. It is possible to configure it at the Mesh level, for all the applications in the Mesh, or just for specific applications.

Here are reasons where you’d want to use this feature:

  • Application metrics are labelled with your mesh parameters (tags, mesh, data plane name…), this means that in mixed Universal and Kubernetes mode metrics are reported with the same types of labels.
  • Both application and sidecar metrics are scraped at the same time. This makes sure they are coherent (with 2 different scrapers they can end up scraping at different intervals and make metrics harder to correlate).
  • If you disable passthrough and your mesh uses mTLS and Prometheus is outside the mesh this is the only way to retrieve these metrics as the app is completely hidden behind the sidecar.

Example section of the configuration:

  1. applications:
  2.   - name: "backend" # application name used for logging and to scope OpenTelemetry metrics (optional)
  3.     path: "/metrics/prometheus" # application metrics endpoint path
  4.     address: # optional custom address if the underlying application listens on a different address than the Data Plane Proxy
  5.     port: 8888 # port on which application is listening

Backends

Prometheus

  1. backends:
  2.   - type: Prometheus
  3.     prometheus: 
  4.       port: 5670
  5.       path: /metrics

This tells Kuma to expose an HTTP endpoint with Prometheus metrics on port 5670 and URI path /metrics.

The metrics endpoint is forwarded to the standard Envoy Prometheus metrics endpoint and supports the same query parameters. You can pass the filter query parameter to limit the results to metrics whose names match a given regular expression. By default, all available metrics are returned.

Secure metrics with TLS

Kuma allows configuring metrics endpoint with TLS.

  1. backends:
  2.   - type: Prometheus
  3.     prometheus: 
  4.       port: 5670
  5.       path: /metrics
  6.       tls:
  7.         mode: ProvidedTLS

In addition to the MeshMetric configuration, kuma-sidecar requires a provided certificate and key for its operation.

When the certificate and key are available within the container, kuma-sidecar needs the paths to provided files as the following environment variables:

  • KUMA_DATAPLANE_RUNTIME_METRICS_CERT_PATH
  • KUMA_DATAPLANE_RUNTIME_METRICS_KEY_PATH

It’s possible to use a ContainerPatch to add variables to kuma-sidecar:

  1. apiVersion: kuma.io/v1alpha1
  2. kind: ContainerPatch
  3. metadata:
  4.   name: container-patch-1
  5.   namespace: kuma-system
  6. spec:
  7.   sidecarPatch:
  8.     - op: add
  9.       path: /env/-
  10.       value: '{
  11.           "name": "KUMA_DATAPLANE_RUNTIME_METRICS_CERT_PATH",
  12.           "value": "/kuma/server.crt"
  13.         }'
  14.     - op: add
  15.       path: /env/-
  16.       value: '{
  17.           "name": "KUMA_DATAPLANE_RUNTIME_METRICS_KEY_PATH",
  18.           "value": "/kuma/server.key"
  19.         }'

Please upload the certificate and the key to the machine, and then define the following environment variables with the correct paths:

  1. * `KUMA_DATAPLANE_RUNTIME_METRICS_CERT_PATH`
  2. * `KUMA_DATAPLANE_RUNTIME_METRICS_KEY_PATH`
activeMTLSBackend

We no longer support activeMTLSBackend, if you need to encrypt and authorize the metrics use Secure metrics with TLS with a combination of one of the authorization methods.

Running multiple prometheus deployments

If you need to run multiple instances of Prometheus and want to target different set of Data Plane Proxies you can do this by using Client ID setting on both MeshMetric (clientId) and Prometheus configuration (client_id).

Support for clientId was added in Prometheus version 2.50.0.

Example Prometheus configuration

Let’s assume we have two prometheus deployments main and secondary. We would like to use each of them to monitor different sets of data plane proxies, with different tags.

We can start with configuring each Prometheus deployments to use Kuma SD. Prometheus’s deployments will be differentiated by client_id parameter.

Main Prometheus config:

  1. scrape_configs:
  2.   - job_name: 'kuma-dataplanes'
  3.     # ...
  4.     kuma_sd_configs:
  5.     - server: http://kuma-control-plane.kuma-system:5676
  6.       refresh_interval: 60s # different from prometheus-secondary
  7.       client_id: "prometheus-main" # Kuma will use this to pick proper data plane proxies

Secondary Prometheus config:

  1. scrape_configs:
  2.   - job_name: 'kuma-dataplanes'
  3.     # ...
  4.     kuma_sd_configs:
  5.       - server: http://kuma-control-plane.kuma-system:5676
  6.         refresh_interval: 20s # different from prometheus-main
  7.         client_id: "prometheus-secondary"

Now we can configure first MeshMetric policy to pick data plane proxies with tag prometheus: main for main Prometheus discovery. clientId in policy should be the same as client_id in Prometheus configuration.

  1. apiVersion: kuma.io/v1alpha1
  2. kind: MeshMetric
  3. metadata:
  4.   name: prometheus-one
  5.   namespace: kuma-system
  6.   labels:
  7.     kuma.io/mesh: default
  8. spec:
  9.   targetRef:
  10.     kind: MeshSubset
  11.     tags:
  12.       prometheus: main
  13.   default:
  14.     backends:
  15.     - type: Prometheus
  16.       prometheus:
  17.         clientId: prometheus-main
  18.         port: 5670
  19.         path: "/metrics"
  1. type: MeshMetric
  2. name: prometheus-one
  3. mesh: default
  4. spec:
  5.   targetRef:
  6.     kind: MeshSubset
  7.     tags:
  8.       prometheus: main
  9.   default:
  10.     backends:
  11.     - type: Prometheus
  12.       prometheus:
  13.         clientId: prometheus-main
  14.         port: 5670
  15.         path: "/metrics"

And policy for secondary Prometheus deployment that will pick dataplane proxies with tag prometheus: secondary.

  1. apiVersion: kuma.io/v1alpha1
  2. kind: MeshMetric
  3. metadata:
  4.   name: prometheus-two
  5.   namespace: kuma-system
  6.   labels:
  7.     kuma.io/mesh: default
  8. spec:
  9.   targetRef:
  10.     kind: MeshSubset
  11.     tags:
  12.       prometheus: secondary
  13.   default:
  14.     backends:
  15.     - type: Prometheus
  16.       prometheus:
  17.         clientId: prometheus-secondary
  18.         port: 5670
  19.         path: "/metrics"
  1. type: MeshMetric
  2. name: prometheus-two
  3. mesh: default
  4. spec:
  5.   targetRef:
  6.     kind: MeshSubset
  7.     tags:
  8.       prometheus: secondary
  9.   default:
  10.     backends:
  11.     - type: Prometheus
  12.       prometheus:
  13.         clientId: prometheus-secondary
  14.         port: 5670
  15.         path: "/metrics"

OpenTelemetry (experimental)

  1. backends:
  2.   - type: OpenTelemetry
  3.     openTelemetry: 
  4.       endpoint: otel-collector.observability.svc:4317

This configuration tells Kuma data plane proxy to push metrics to OpenTelemetry collector. Dataplane Proxy will scrape metrics from Envoy and other applications in a Pod/VM. and push them to configured OpenTelemetry collector.

When you configure application scraping make sure to specify application.name to utilize OpenTelemetry scoping

Limitations
  • You cannot configure scraping interval for OpenTelemetry. By default, it will publish metrics to collector every 30 seconds. Ability to configure scraping interval in policy will be added in the future.
  • Right now Kuma supports configuring only one OpenTelemetry backend.

  • OpenTelemetry integration does not take sidecar configuration into account. This support will be added in the next release.

  • Application must expose metrics in Prometheus format for this integration to work

Examples

With custom port, path, clientId, application aggregation and service override

The first policy defines a default MeshMetric policy for the default mesh. The second policy creates an override for workloads tagged with framework: example-web-framework. That web framework exposes metrics under /metrics/prometheus and port 8888.

  1. apiVersion: kuma.io/v1alpha1
  2. kind: MeshMetric
  3. metadata:
  4.   name: metrics-default
  5.   namespace: kuma-system
  6.   labels:
  7.     kuma.io/mesh: default
  8. spec:
  9.   targetRef:
  10.     kind: Mesh
  11.   default:
  12.     sidecar:
  13.       includeUnused: false
  14.     backends:
  15.     - type: Prometheus
  16.       prometheus:
  17.         clientId: main-backend
  18.         port: 5670
  19.         path: "/metrics"
  20.         tls:
  21.           mode: ProvidedTLS
  1. type: MeshMetric
  2. mesh: default
  3. name: metrics-default
  4. spec:
  5.   targetRef:
  6.     kind: Mesh
  7.   default:
  8.     sidecar:
  9.       includeUnused: false
  10.     backends:
  11.     - type: Prometheus
  12.       prometheus:
  13.         clientId: main-backend
  14.         port: 5670
  15.         path: "/metrics"
  16.         tls:
  17.           mode: ProvidedTLS
  1. apiVersion: kuma.io/v1alpha1
  2. kind: MeshMetric
  3. metadata:
  4.   name: metrics-for-mesh-service
  5.   namespace: kuma-system
  6.   labels:
  7.     kuma.io/mesh: default
  8. spec:
  9.   targetRef:
  10.     kind: MeshSubset
  11.     tags:
  12.       framework: example-web-framework
  13.   default:
  14.     applications:
  15.     - path: "/metrics/prometheus"
  16.       port: 8888
  1. type: MeshMetric
  2. mesh: default
  3. name: metrics-for-mesh-service
  4. spec:
  5.   targetRef:
  6.     kind: MeshSubset
  7.     tags:
  8.       framework: example-web-framework
  9.   default:
  10.     applications:
  11.     - path: "/metrics/prometheus"
  12.       port: 8888

All policy options