通过入口访问所有 kubernetes statefulset pod

Question

Using a STS with 3 pods: "pod-0, pod-1, pod-2" to create an Apache Spark cluster, each pod is a worker with logs available via HTTP.

In order to see logs, I would like to access to all pods via a HTTP ingress, something like:

"https://pod-0.my-ingress.domain" or "https://my-ingress.domain/pod-0"

Is it possible to do this automatically by declaring a single Ingress?

Answer 1

There is no out of the box solution in kubernetes for this, but you could create service per each pod in the statefulset and then reference it in the ingress:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: sts-ingress
spec:
  rules:
  - http:
      paths:
      - path: /pod-0
        pathType: Prefix
        backend:
          service:
            name: pod-0
            port:
              number: 80
      - path: /pod-1
        pathType: Prefix
        backend:
          service:
            name: pod-1
            port:
              number: 80

You could leverage operator pattern to automate it, an example of metacontroller already exists for this use case: https://github.com/metacontroller/metacontroller/tree/master/examples/service-per-pod

Answer 2

I had the same kind of issue with a DaemonSet.

I solve my issue with a Docker image: dyn-ingress

This container needs access to the Host Kubernetes:

• Ingress to maintain Ingress routes to all pods.
• Service to create and maintain a dedicated service per pod.
• Pod to watch them and add labels on them.

The current version only support adding route like: http://<host>/nodename/ And host a webServer that can list the current nodes.

For your case you prefer url likes http://<host>/podname/ or http://podname.<host>/

I'm looking for feedback.