Traffic Trace

This policy enables tracing logging to a third party tracing solution.

Tracing is supported on any HTTP traffic in a Mesh, and will only work with data plane proxies and services that have the Kuma kuma.io/protocol: http tag defined. Check the protocol support for more details on how to set the protocol tag in the different environments.

In order to enable tracing there are two steps that have to be taken:

On Kubernetes we can run kumactl install tracing | kubectl apply -f - to deploy Jaeger automatically in a kuma-tracing namespace.

Add a tracing backend

A tracing backend must be first specified in a Mesh resource. Once added, the tracing backend will be available for use in the TrafficTrace resource.

While most commonly we want all the traces to be sent to the same tracing backend, we can optionally create multiple tracing backends in a Mesh resource and store traces for different paths of our service traffic in different backends (by leveraging Kuma Tags). This is especially useful when we want traces to never leave a world region, or a cloud, among other examples.

The types supported are:

To add a new tracing backend we must create a new tracing property in a Mesh resource:

  1. apiVersion: kuma.io/v1alpha1
  2. kind: Mesh
  3. metadata:
  4.   name: default
  5. spec:
  6.   tracing:
  7.     defaultBackend: jaeger-collector
  8.     backends:
  9.     - name: jaeger-collector
  10.       type: zipkin
  11.       sampling: 100.0
  12.       conf:
  13.         url: http://jaeger-collector.kuma-tracing:9411/api/v2/spans

We will apply the configuration with kubectl apply -f [..].

  1. type: Mesh
  2. name: default
  3. tracing:
  4.   defaultBackend: jaeger-collector
  5.   backends:
  6.   - name: jaeger-collector
  7.     type: zipkin
  8.     sampling: 100.0
  9.     conf:
  10.       url: http://jaeger-collector.kuma-tracing:9411/api/v2/spans

We will apply the configuration with kumactl apply -f [..] or via the HTTP API.

We can also specify a defaultBackend property that will be used if any TrafficTrace resource doesn’t explicitly specify a tracing backend.

Add a TrafficTrace resource

Once we have added a tracing backend, we can now create TrafficTrace resources that will determine how we are going to collecting traces, and what backend we should be using to store them.

  1. apiVersion: kuma.io/v1alpha1
  2. kind: TrafficTrace
  3. mesh: default
  4. metadata:
  5.   name: trace-all-traffic
  6. spec:
  7.   selectors:
  8.   - match:
  9.       kuma.io/service: '*'
  10.   conf:
  11.     backend: jaeger-collector

We will apply the configuration with kubectl apply -f [..].

  1. type: TrafficTrace
  2. name: trace-all-traffic
  3. mesh: default
  4. selectors:
  5. - match:
  6.     kuma.io/service: '*'
  7. conf:
  8.   backend: jager-collector

We will apply the configuration with kumactl apply -f [..] or via the HTTP API.

We can use Kuma Tags to apply the TrafficTrace resource in a more target way to a subset of data plane proxies as opposed to all of them (like we do in the example by using the kuma.io/service: '*' selector),

It is important that we instrument our services to preserve the trace chain between requests that are made across different services. We can either use a library in the language of our choice, or we can manually pass the following headers:

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

As noted before, Envoy’s Zipkin tracer is also compatible with Jaeger through Zipkin V2 HTTP API.Traffic Trace - 图2 (opens new window).

Matching

TrafficTrace is a Dataplane policy. You can use all the tags in the selectors section.