Exec probe configuration in Kubernetes - Mini Project: Build & Apply

Exec Probe Configuration in Kubernetes

📖 Scenario: You are managing a Kubernetes deployment for a simple web application. You want to ensure the application container is healthy by running a command inside the container periodically. This helps Kubernetes know if the container is working properly and restart it if needed.

🎯 Goal: Configure an exec liveness probe in a Kubernetes Pod manifest that runs a command inside the container to check its health.

📋 What You'll Learn

Create a Pod manifest with a container named webapp

Add an exec liveness probe that runs the command ['cat', '/tmp/healthy']

Set the probe to run every 5 seconds

Print the final Pod manifest YAML

💡 Why This Matters

🌍 Real World

Exec probes are used in Kubernetes to check container health by running commands inside containers. This helps keep applications running smoothly by restarting unhealthy containers automatically.

💼 Career

Understanding exec probes is essential for Kubernetes administrators and DevOps engineers to maintain reliable containerized applications.

1

Create the basic Pod manifest

Create a Kubernetes Pod manifest named pod.yaml with a single container named webapp using the image busybox. The container should run the command ['sleep', '3600'] to keep it alive.

Kubernetes

# Write the Pod manifest YAML with apiVersion, kind, metadata, and spec including the container

Need a hint?

Use apiVersion: v1, kind: Pod, and define containers with the specified name, image, and command.

2

Add the exec liveness probe configuration

Add a livenessProbe section to the webapp container. Configure it to use an exec command that runs ['cat', '/tmp/healthy'].

Kubernetes

apiVersion: v1
kind: Pod
metadata:
  name: webapp-pod
spec:
  containers:
  - name: webapp
    image: busybox
    command: ['sleep', '3600']
    # Add livenessProbe with exec command here

Need a hint?

Under livenessProbe, use exec with a command list containing cat and /tmp/healthy.

3

Set the probe interval

Add the periodSeconds field to the livenessProbe and set it to 5 so the probe runs every 5 seconds.

Kubernetes

apiVersion: v1
kind: Pod
metadata:
  name: webapp-pod
spec:
  containers:
  - name: webapp
    image: busybox
    command: ['sleep', '3600']
    livenessProbe:
      exec:
        command:
        - cat
        - /tmp/healthy
      # Add periodSeconds: 5 below

Need a hint?

Add periodSeconds: 5 under livenessProbe to set the probe interval.

4

Print the final Pod manifest

Print the complete Pod manifest YAML to verify your configuration.

Kubernetes

# Print the Pod manifest YAML
# Your code here

Need a hint?

Use a print statement to output the full YAML manifest exactly as configured.