Does Traefik send span context when forwarding request for authorization?

Hi there,

I am about to configure a distributed tracing solution with Jaeger. Traefik v1.7.11 plays ingress role in our kubernetes clusters. I have added the tracing configuration to traefik and I see all the logged spans.

Problem:
I have three services: 1. Traefik (ingress), 2. Authorization Service (wsp), 3. Random service which has the auth forwarding configuration with the following annotations.

I have configured the auth-forward method with annotations:

  - item: "ingress.kubernetes.io/auth-type: forward"
  - item: "ingress.kubernetes.io/auth-url: <auth url>"
  - item: "ingress.kubernetes.io/auth-response-headers: X-Auth-User, X-Auth-Partner"

When my authorization service handles the forwarded requests I can see some headers, but the span context header (Custom-Trace-Id) with the trace id is missing.

    [tracing]
      backend = "jaeger"
      serviceName = "traefik"
      spanNameLimit = 0

      [tracing.jaeger]
        samplingServerURL = "<sampling-server-url>"
        # TODO
        samplingType = "const"
        # TODO
        samplingParam = 1.0
        localAgentHostPort = "<agent-url>"
        traceContextHeaderName = "Custom-Trace-Id"

The received headers:
User-Agent:, Accept-Language,Referer,X-Real-Ip,X-Forwarded-Proto,X-Forwarded-Uri,Accept,Accept-Encoding,Authorization,X-Forwarded-For, X-Forwarded-Host,X-Forwarded-Method

The reason I need it: I want to see all the spans from the beginning (from traefik receives the requests) including the authorization method's spans.

Am I missing something, or it is not supported currently in Traefik v1.7.11?

Thanks in advance.

Kind regards,
csu

the quick answer after several days: nope