Kubernetes ingress unhealthy backend

Question

I've been using this load-balancer tutorial. It works fine when I use ngnix image but if I try and use my own app image it changes the backend to unhealthy.

My application redirects on / (returns a 302) but I added a livenessProbe in the pod definition:

    livenessProbe:
      httpGet:
        path: /ping
        port: 4001
        httpHeaders:
          - name: X-health-check
            value: kubernetes-healthcheck
          - name: X-Forwarded-Proto
            value: https
          - name: Host
            value: foo.bar.com

My ingress:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: foo
spec:
  backend:
    serviceName: foo
    servicePort: 80
  rules:
  - host: foo.bar.com

Service configuration:

kind: Service
apiVersion: v1
metadata:
  name: foo
spec:
  type: NodePort
  selector:
    app: foo
  ports:
    - port: 80 
      targetPort: 4001

When I do a ingress describe I get:

backends:       {"k8s-be-32180--5117658971cfc555":"UNHEALTHY"}

The ingress rules:

Rules:
  Host  Path    Backends
  ----  ----    --------
  * *   foo:80 (10.0.0.7:4001,10.0.1.6:4001)

Answer 1

Add a readinessProbe(copy your livenessProbe). It's explained in the GCE L7 Ingress Docs.

Health checks

Currently, all service backends must satisfy either of the following requirements to pass the HTTP health checks sent to it from the GCE loadbalancer: 1. Respond with a 200 on '/'. The content does not matter. 2. Expose an arbitrary url as a readiness probe on the pods backing the Service.

Just make sure that your readinessProbe is pointing to the same port that you exposed for ingress. It seems fine in your case because you've got just one port but just in case you want to add another you may get errors.

Also don't use the custom headers in you readinessProbe. They seem to cause trouble sometimes