Node selectors for simple scheduling in Kubernetes - Mini Project: Build & Apply

Node selectors for simple scheduling

📖 Scenario: You are managing a Kubernetes cluster with different types of nodes. You want to schedule a pod to run only on nodes that have a specific label, such as disktype: ssd. This helps ensure your pod runs on nodes with fast storage.

🎯 Goal: Create a pod manifest that uses a node selector to schedule the pod only on nodes labeled with disktype: ssd.

📋 What You'll Learn

Create a pod manifest with metadata name fast-storage-pod

Add a container named app-container running the image nginx

Add a nodeSelector field to schedule the pod on nodes with label disktype: ssd

Print the final pod manifest YAML

💡 Why This Matters

🌍 Real World

Node selectors are used in Kubernetes to ensure pods run on nodes with specific hardware or software characteristics, like SSD storage or GPU support.

💼 Career

Understanding node selectors is important for Kubernetes administrators and DevOps engineers to optimize workload placement and resource usage.

1

Create the basic pod manifest

Create a YAML manifest for a pod named fast-storage-pod with a container named app-container running the image nginx. Do not add node selectors yet.

Kubernetes

# Your YAML manifest here
apiVersion: v1
kind: Pod
metadata:
  name: fast-storage-pod
spec:
  containers:
  - name: app-container
    image: nginx

Need a hint?

Start with the basic pod YAML structure. Use apiVersion: v1 and kind: Pod. Add metadata with the pod name and a container spec.

2

Add the node selector

Add a nodeSelector field under spec with the key disktype and value ssd to schedule the pod on nodes labeled disktype: ssd.

Kubernetes

apiVersion: v1
kind: Pod
metadata:
  name: fast-storage-pod
spec:
  containers:
  - name: app-container
    image: nginx
  # Add nodeSelector here

Need a hint?

Under spec, add nodeSelector: and then the label key and value as a map.

3

Verify the pod manifest structure

Check that the pod manifest includes nodeSelector with disktype: ssd and the container named app-container with image nginx.

Kubernetes

# Review your YAML manifest to ensure it has the correct nodeSelector and container details
# Your code here

Need a hint?

Make sure the nodeSelector and container details are exactly as specified.

4

Print the final pod manifest

Print the complete pod manifest YAML to display the pod configuration with the node selector.

Kubernetes

# Print the pod manifest YAML
print(pod_manifest_yaml)

Need a hint?

Store the YAML as a string variable and print it exactly.