Readiness endpoint about traefik

[sfudeus]

We are suffering from the same problem. Traefik is reporting readiness before all currently deployed K8s ingress manifest are consumed, causing 404 errors anytime new traefik pods come up (during redeploys or scaling events).
Especially for instances with many ingresses this is a problem (our biggest tenants have up to 400 ingresses).

Thanks for the hint with /api/rawdata, I am now using this as a workaround in a sidecar container by checking it multiple times on a loop until the amount of routers has been constant within a defined stabilization window. I am using a sidecar instead of a startupProbe in the traefik container to have more tooling (curl, jq) available. The check is only done initially and checked by a startupProbe, the sidecar sleeps afterwards.

[nmengin]

Hey @mloiseleur!

Thanks for your suggestion.
We are interested in this issue, but we’re unsure about the use case and the traction it will receive. We are going to leave the status as kind/proposal to give the community time to let us know if they would like this idea.

We will reevaluate as people respond.

[sfudeus]

but we’re unsure about the use case

I thought this is rather obvious. Currently, traefik pods become ready and as such attract traffic before having consumed all relevant configuration data from the Kubernetes API.

Consequence: Clients see error 404 for their requests for a while, while traefik becomes ready over time.

[mossroy]

I confirm the issue.
Without this endpoint, I don't find a generic and reliable way to setup a k8s probe that tells if traefik is really ready.

So, when Traefik has not setup all its routes, but is already considered "ready" by k8s (with its default probe), part of the traffic can be sent to a wrong route.

In my case, I have some routes that require a Basic Auth and/or use the default self-signed TLS certificate.
As a consequence, the user can receive a Basic Auth pop-up where there should not be any and/or a browser warning about the TLS certificate. It's very disturbing for users, and can happen on each Traefik restart.