Kubernetes: Liveness/Readiness check for external Endpoints Services

[ChristianCiach]

Traefik IngressRoute has no support for health checks. Unfortunately, the issue #6492 has been closed with this comment:

You have to use the heathcheck systems from k8s.

As we can read here, Kubernetes has no support for health checks of headless services (with custom Endpoints) or services of type ExternalName: kubernetes/kubernetes#77738 (comment)

This leaves us with the unsatisfying situation that it is currently impossible to have health checks for external services when using the KubernetesCRD provider.

I see no good reason for omitting this feature from KubernetesCRD and forcing people to use the file provider instead.

Please see the comments starting at #6492 (comment) for further use-cases of this feature.

[marcmognol]

Dear traefik team,

Is there any solution that you could provide to anwser our needs?
I would like to use Traefik as a load balancer for some services hosted outside our Kubernetes cluster, so today I use file provider and it worked like a charm.

But I would prefere using CRD resources.

Would be possible to have the same level of feature between the CRD and the file provider for Service objects ?

Thanks

Marc

[emilevauge]

If someone from the community wants to contribute on this, the maintainers team would love to support & help :)

[marcmognol]

Hi @emilevauge,
Thank you for your reply.

Are we in line that the need is to be able to use a CRD type TraefikService, in order to replace the following configuration in file ?

  services:
    uat-service:
      loadBalancer:
        serversTransport: uat-transport
        servers:
          - url: https://localserver-1.asf.pri:443
          - url: https://localserver-2.asf.pri:443
        healthCheck:
          hostname: uat.local.pri
          path: /landing-page/
          interval: 15s
        sticky:
          cookie:
            secure: true
            httpOnly: true

[marcmognol]

I will try to do a PR soon to handle service LoadBalancer type from CRD.

[kevinpollet]

Hello @ChristianCiach and thanks for opening this issue,

We missed during the triage that we had another issue about adding the HeatlhCheck feature for external services in K8S. To keep discussions focused on only one issue I am closing this one as a duplicate of #8541 as it contains details on how the issue can be solved, as well as a corresponding draft pull request.