Why cluster monitoring matters in Kubernetes - See It in Action

Why Cluster Monitoring Matters

📖 Scenario: You are managing a Kubernetes cluster that runs several applications for your company. To keep everything running smoothly, you need to monitor the cluster's health and resource usage.

🎯 Goal: Learn how to set up basic cluster monitoring by creating a simple Kubernetes ConfigMap with monitoring settings, then apply a label selector to identify monitored nodes, and finally list the nodes being monitored.

📋 What You'll Learn

Create a ConfigMap named monitoring-config with a key enabled set to true

Create a label selector variable called monitor_label with the value monitor=true

Use kubectl get nodes -l monitor=true command to list nodes with the monitoring label

Print the output of the command

💡 Why This Matters

🌍 Real World

Monitoring Kubernetes clusters is essential to ensure applications run smoothly and resources are used efficiently.

💼 Career

DevOps engineers and site reliability engineers use cluster monitoring to detect issues early and maintain system stability.

1

Create a ConfigMap for monitoring

Create a Kubernetes ConfigMap named monitoring-config with a data key enabled set to true using the kubectl create configmap command.

Kubernetes

# Use kubectl create configmap monitoring-config --from-literal=enabled=true
# Your code here

Need a hint?

Use kubectl create configmap monitoring-config --from-literal=enabled=true to create the ConfigMap.

2

Set a label selector variable

Create a shell variable called monitor_label and set it to the string monitor=true.

Kubernetes

kubectl create configmap monitoring-config --from-literal=enabled=true
# Create a variable monitor_label with value 'monitor=true'
# Your code here

Need a hint?

Use monitor_label="monitor=true" to create the variable.

3

List nodes with the monitoring label

Use the kubectl get nodes command with the label selector stored in monitor_label to list all nodes labeled for monitoring.

Kubernetes

kubectl create configmap monitoring-config --from-literal=enabled=true
monitor_label="monitor=true"
# Use kubectl get nodes with label selector from monitor_label
# Your code here

Need a hint?

Use kubectl get nodes -l $monitor_label to list nodes with the label.

4

Display the monitored nodes

Print the output of the kubectl get nodes -l $monitor_label command to show the nodes currently monitored.

Kubernetes

kubectl create configmap monitoring-config --from-literal=enabled=true
monitor_label="monitor=true"
kubectl get nodes -l $monitor_label
# Print the output of the above command
# Your code here

Need a hint?

Running kubectl get nodes -l $monitor_label will print the nodes with the label.