How to configure Kubernetes health probes¶

This guide shows you how to point Kubernetes liveness, readiness, and startup probes at the plone.observability health server.

It assumes the healthserver filter is wired and the health server listens on port 8081. See How to install plone.observability.

Expose the health port¶

Declare the health port on the container alongside the main Zope port.

ports:
  - name: http
    containerPort: 8080
  - name: health
    containerPort: 8081

Configure the three probes¶

livenessProbe:
  httpGet:
    path: /live
    port: 8081
  initialDelaySeconds: 10
  periodSeconds: 30
  failureThreshold: 3

readinessProbe:
  httpGet:
    path: /ready
    port: 8081
  initialDelaySeconds: 5
  periodSeconds: 10
  failureThreshold: 3

startupProbe:
  httpGet:
    path: /startup
    port: 8081
  failureThreshold: 30
  periodSeconds: 10

Tune the startup budget for slow boots¶

Plone can take a while to boot. The startup probe protects it: Kubernetes runs the liveness and readiness probes only after the startup probe has succeeded.

Size the startup budget to your slowest realistic boot. With failureThreshold: 30 and periodSeconds: 10, Kubernetes allows up to 300 seconds for startup before it gives up. Raise failureThreshold if your site boots more slowly; the probe latches green on first success, so a generous budget costs nothing on a fast boot.