HTTP probe configuration in Kubernetes - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an HTTP readiness probe in Kubernetes?

An HTTP readiness probe checks if a container is ready to accept traffic by sending an HTTP request to a specified endpoint. If the probe succeeds, Kubernetes routes traffic to the container.

beginner

What fields are essential to configure an HTTP liveness probe in a Pod spec?

Key fields include httpGet (with path and port), initialDelaySeconds, periodSeconds, and timeoutSeconds. These define how Kubernetes checks if the container is alive.

beginner

How does Kubernetes react if an HTTP liveness probe fails repeatedly?

If the liveness probe fails multiple times, Kubernetes restarts the container to try to fix the problem and keep the application healthy.

intermediate

What is the difference between readiness and liveness probes using HTTP?

Readiness probes check if the app is ready to serve traffic, while liveness probes check if the app is alive and should be restarted if not responding.

beginner

Show a simple example of an HTTP readiness probe configuration in a Kubernetes Pod spec.

Example:<br>

readinessProbe:
  httpGet:
    path: /health
    port: 8080
  initialDelaySeconds: 5
  periodSeconds: 10

What does the httpGet field specify in an HTTP probe?

A The container image to use

B The command to run inside the container

C The TCP port to open

D The HTTP path and port to check

The httpGet field tells Kubernetes which HTTP path and port to request to check the container's health.

What happens if a readiness probe fails?

A Kubernetes stops sending traffic to the container

B Kubernetes restarts the container immediately

C Nothing happens

D The pod is deleted

If readiness probe fails, Kubernetes marks the container as not ready and stops sending traffic to it.

Which field controls how long Kubernetes waits before starting probes?

A timeoutSeconds

B periodSeconds

C initialDelaySeconds

D failureThreshold

initialDelaySeconds sets the wait time before the first probe runs.

What is the default protocol used in an HTTP probe?

A HTTPS

B HTTP

C TCP

D UDP

HTTP probes use the HTTP protocol by default to check container health.

If an HTTP liveness probe fails, what is Kubernetes' typical response?

A Restart the container

B Stop the pod permanently

C Ignore the failure

D Send an alert only

Kubernetes restarts containers when liveness probes fail repeatedly to recover from failure.

Explain how to configure an HTTP readiness probe in a Kubernetes Pod and why it is important.

Think about how Kubernetes knows when to send traffic to your app.

Describe the difference between HTTP liveness and readiness probes and their effects on container lifecycle.

One decides if the app gets traffic, the other decides if the app needs restarting.