Readiness probe concept in Kubernetes - Mini Project: Build & Apply

Readiness Probe Concept in Kubernetes

📖 Scenario: You are deploying a web application in Kubernetes. You want to make sure the application only receives traffic when it is ready to serve users. Kubernetes uses a readiness probe to check if the app is ready.

🎯 Goal: Learn how to add a readiness probe to a Kubernetes pod configuration to check the app's readiness using an HTTP GET request.

📋 What You'll Learn

Create a pod manifest with a container named webapp

Add a readiness probe that uses an HTTP GET request on path /ready and port 8080

Set initial delay seconds to 5 and period seconds to 10

Print the pod manifest YAML to verify the readiness probe is configured

💡 Why This Matters

🌍 Real World

Readiness probes help Kubernetes know when your app is ready to receive traffic, avoiding errors and improving user experience.

💼 Career

Understanding readiness probes is essential for DevOps roles managing Kubernetes deployments to ensure reliable and stable applications.

1

Create the basic pod manifest

Create a Kubernetes pod manifest named pod.yaml with a pod named webapp-pod and a container named webapp using the image nginx.

Kubernetes

# Create a pod manifest with name webapp-pod and container webapp using nginx image
# Your code here

Need a hint?

Use apiVersion: v1, kind: Pod, and specify metadata.name and spec.containers.

2

Add readiness probe configuration

Add a readinessProbe to the webapp container that uses an HTTP GET request on path /ready and port 8080.

Kubernetes

apiVersion: v1
kind: Pod
metadata:
  name: webapp-pod
spec:
  containers:
  - name: webapp
    image: nginx
    # Add readinessProbe with httpGet path /ready and port 8080
    # Your code here

Need a hint?

Indent readinessProbe under the container and use httpGet with path and port.

3

Set initial delay and period seconds for readiness probe

Add initialDelaySeconds: 5 and periodSeconds: 10 to the readinessProbe configuration.

Kubernetes

apiVersion: v1
kind: Pod
metadata:
  name: webapp-pod
spec:
  containers:
  - name: webapp
    image: nginx
    readinessProbe:
      httpGet:
        path: /ready
        port: 8080
      # Add initialDelaySeconds: 5 and periodSeconds: 10 here
      # Your code here

Need a hint?

Place initialDelaySeconds and periodSeconds at the same level as httpGet inside readinessProbe.

4

Print the pod manifest

Print the complete pod manifest YAML to verify the readiness probe is configured correctly.

Kubernetes

# Print the pod manifest YAML
# Your code here

Need a hint?

Use a print statement to show the manifest is ready.