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:

• 1. Add a tracing backend
• 2. Add a TrafficTrace resource

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:

• zipkin. You can also use this with Jaeger (opens new window) since it supports Zipkin compatible traces.

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

apiVersion: kuma.io/v1alpha1
kind: Mesh
metadata:
  name: default
spec:
  tracing:
    defaultBackend: jaeger-collector
    backends:
    - name: jaeger-collector
      type: zipkin
      sampling: 100.0
      conf:
        url: http://jaeger-collector.kuma-tracing:9411/api/v2/spans

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

type: Mesh
name: default
tracing:
  defaultBackend: jaeger-collector
  backends:
  - name: jaeger-collector
    type: zipkin
    sampling: 100.0
    conf:
      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.

apiVersion: kuma.io/v1alpha1
kind: TrafficTrace
mesh: default
metadata:
  name: trace-all-traffic
spec:
  selectors:
  - match:
      kuma.io/service: '*'
  conf:
    backend: jaeger-collector

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

type: TrafficTrace
name: trace-all-traffic
mesh: default
selectors:
- match:
    kuma.io/service: '*'
conf:
  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. (opens new window).