Node affinity and anti-affinity in Kubernetes - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify node affinity that requires pods to run on nodes with the label 'disktype: ssd'.

Kubernetes

nodeAffinity:
  requiredDuringSchedulingIgnoredDuringExecution:
    nodeSelectorTerms:
    - matchExpressions:
      - key: "disktype"
        operator: [1]
        values:
        - "ssd"

Drag options to blanks, or click blank then click option'

AExists

BNotIn

CIn

DDoesNotExist

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Exists' which only checks if the label key exists, not its value.

Using 'NotIn' which excludes nodes with the value 'ssd'.

The operator In is used to specify that the node label 'disktype' must have the value 'ssd' for the pod to be scheduled on that node.

2fill in blank

medium

Complete the code to specify node anti-affinity that avoids scheduling pods on nodes with label 'zone: us-east-1a'.

Kubernetes

podAntiAffinity:
  requiredDuringSchedulingIgnoredDuringExecution:
  - labelSelector:
      matchExpressions:
      - key: "zone"
        operator: [1]
        values:
        - "us-east-1a"
    topologyKey: "kubernetes.io/hostname"

Drag options to blanks, or click blank then click option'

AExists

BNotIn

CDoesNotExist

DIn

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'NotIn' which would select pods not in the zone, thus not avoiding the zone.

Using 'Exists' which ignores the value and matches any pod with the label.

The operator In is used here to select pods running on nodes with label 'zone: us-east-1a' to avoid scheduling new pods on the same nodes.

3fill in blank

hard

Fix the error in the node affinity expression to correctly require nodes with label 'env: production'.

Kubernetes

nodeAffinity:
  requiredDuringSchedulingIgnoredDuringExecution:
    nodeSelectorTerms:
    - matchExpressions:
      - key: "env"
        operator: [1]
        values:
        - "production"

Drag options to blanks, or click blank then click option'

AIn

BNotIn

CExists

DDoesNotExist

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'NotIn' which excludes nodes with 'production' label.

Using 'Exists' which ignores the label value.

The correct operator to require nodes with label 'env' equal to 'production' is In.

4fill in blank

hard

Fill both blanks to create a pod anti-affinity rule that avoids scheduling pods on nodes with pods labeled 'app: frontend' in the same zone.

Kubernetes

podAntiAffinity:
  requiredDuringSchedulingIgnoredDuringExecution:
  - labelSelector:
      matchExpressions:
      - key: [1]
        operator: [2]
        values:
        - "frontend"
    topologyKey: "failure-domain.beta.kubernetes.io/zone"

Drag options to blanks, or click blank then click option'

Aapp

BIn

Cenv

DNotIn

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'env' as key which does not match the label.

Using 'NotIn' which selects pods without 'frontend' label.

The key is 'app' to match pods labeled 'app: frontend'. The operator 'In' selects pods with that label value to avoid colocating.

5fill in blank

hard

Fill all three blanks to define a node affinity that prefers nodes with label 'region: us-west' and requires nodes with label 'ssd: true'.

Kubernetes

nodeAffinity:
  preferredDuringSchedulingIgnoredDuringExecution:
  - weight: 1
    preference:
      matchExpressions:
      - key: [1]
        operator: [2]
        values:
        - "us-west"
  requiredDuringSchedulingIgnoredDuringExecution:
    nodeSelectorTerms:
    - matchExpressions:
      - key: [3]
        operator: In
        values:
        - "true"

Drag options to blanks, or click blank then click option'

Aregion

BIn

Cssd

DExists

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up keys 'region' and 'ssd'.

Using 'Exists' operator which ignores label values.

The preferred affinity uses key 'region' with operator 'In' to prefer nodes in 'us-west'. The required affinity uses key 'ssd' with operator 'In' to require nodes labeled 'ssd: true'.