MeshTrace (beta)

This policy uses new policy matching algorithm and is in beta state, it should not be mixed with TrafficTrace.

This policy enables publishing traces to a third party tracing solution.

Tracing is supported over HTTP, HTTP2, and gRPC protocols. You must explicitly specify the protocol for each service and data plane proxy you want to enable tracing for.

Kuma currently supports the following trace exposition formats:

Services still need to be instrumented to preserve the trace chain across requests made across different services.

You can instrument with a language library of your choice (for zipkin and for datadog). For HTTP you can also manually forward the following headers:

  • x-request-id
  • x-b3-traceid
  • x-b3-parentspanid
  • x-b3-spanid
  • x-b3-sampled
  • x-b3-flags

TargetRef support matrix

TargetRef type top level to from
Mesh
MeshSubset
MeshService
MeshServiceSubset
MeshGatewayRoute

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

Configuration

Sampling

Most of the time setting only overall is sufficient. random and client are for advanced use cases.

You can configure sampling settings equivalent to Envoy’s:

The value is always a percentage and is between 0 and 100.

Example:

sampling:
  overall: 80
  random: 60
  client: 40

Tags

You can add tags to trace metadata by directly supplying the value (literal) or by taking it from a header (header).

Example:

tags:
  - name: team
    literal: core
  - name: env
    header:
      name: x-env
      default: prod
  - name: version
    header:
      name: x-version

If a value is missing for header, default is used. If default isn’t provided, then the tag won’t be added.

Backends

Datadog

You can configure a Datadog backend with a url and splitService.

Example:

datadog:
  url: http://my-agent:8080 # Required. The url to reach a running datadog agent
  splitService: true # Default to false. If true, it will split inbound and outbound requests in different services in Datadog

The splitService property determines if Datadog service names should be split based on traffic direction and destination. For example, with splitService: true and a backend service that communicates with a couple of databases, you would get service names like backend_INBOUND, backend_OUTBOUND_db1, and backend_OUTBOUND_db2 in Datadog.

Zipkin

In most cases the only field you’ll want to set in url.

Example:

zipkin:
  url: http://jaeger-collector:9411/api/v2/spans # Required. The url to a zipkin collector to send traces to 
  traceId128bit: false # Default to false which will expose a 64bits traceId. If true, the id of the trace is 128bits
  apiVersion: httpJson # Default to httpJson. It can be httpJson, httpProto and is the version of the zipkin API
  sharedSpanContext: false # Default to true. If true, the inbound and outbound traffic will share the same span. 

Examples

Zipkin

Simple example:

apiVersion: kuma.io/v1alpha1
kind: MeshTrace
metadata:
  name: default
  namespace: kuma-system
  labels:
    kuma.io/mesh: default # optional, defaults to `default` if unset
spec:
  targetRef:
    kind: Mesh
  default:
    backends:
      - zipkin:
          url: http://jaeger-collector.mesh-observability:9411/api/v2/spans

Full example:

apiVersion: kuma.io/v1alpha1
kind: MeshTrace
metadata:
  name: default
  namespace: kuma-system
  labels:
    kuma.io/mesh: default # optional, defaults to `default` if unset
spec:
  targetRef:
    kind: Mesh
  default:
    backends:
      - zipkin:
          url: http://jaeger-collector.mesh-observability:9411/api/v2/spans
          apiVersion: httpJson
    tags:
      - name: team
        literal: core
      - name: env
        header:
          name: x-env
          default: prod
      - name: version
        header:
          name: x-version
    sampling:
      overall: 80
      random: 60
      client: 40

Apply the configuration with kubectl apply -f [..].

Datadog

This assumes a Datadog agent is configured and running. If you haven’t already check the Datadog observability page.

Simple Example:

apiVersion: kuma.io/v1alpha1
kind: MeshTrace
metadata:
  name: default
  namespace: kuma-system
  labels:
    kuma.io/mesh: default # optional, defaults to `default` if unset
spec:
  targetRef:
    kind: Mesh
  default:
    backends:
      - datadog:
          url: http://trace-svc.default.svc.cluster.local:8126

Full Example:

apiVersion: kuma.io/v1alpha1
kind: MeshTrace
metadata:
  name: default
  namespace: kuma-system
  labels:
    kuma.io/mesh: default # optional, defaults to `default` if unset
spec:
  targetRef:
    kind: Mesh
  default:
    backends:
      - datadog:
          url: http://trace-svc.default.svc.cluster.local:8126
          splitService: true
    tags:
      - name: team
        literal: core
      - name: env
        header:
          name: x-env
          default: prod
      - name: version
        header:
          name: x-version
    sampling:
      overall: 80
      random: 60
      client: 40

where trace-svc is the name of the Kubernetes Service you specified when you configured the Datadog APM agent.

Apply the configuration with kubectl apply -f [..].

Targeting parts of the infrastructure

While usually you want all the traces to be sent to the same tracing backend, you can target parts of a Mesh by using a finer-grained targetRef and a designated backend to trace different paths of our service traffic. This is especially useful when you want traces to never leave a world region, or a cloud, for example.

In this example, we have two zones east and west, each of these with their own Zipkin collector: east.zipkincollector:9411/api/v2/spans and west.zipkincollector:9411/api/v2/spans. We want dataplane proxies in each zone to only send traces to their local collector.

To do this, we use a TargetRef kind value of MeshSubset to filter which dataplane proxy a policy applies to.

West only policy:

type: MeshTrace
name: trace-west
mesh: default
spec:
  targetRef:
    kind: MeshSubset
    tags:
      kuma.io/zome: west
  default:
    backends:
      - zipkin:
          url: http://west.zipkincollector:9411/api/v2/spans

East only policy:

type: MeshTrace
name: trace-east
mesh: default
spec:
  targetRef:
    kind: MeshSubset
    tags:
      kuma.io/zome: east
  default:
    backends:
      - zipkin:
          url: http://east.zipkincollector:9411/api/v2/spans
Last Updated: 11/7/2022, 16:49:06 PM