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

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify pod affinity for pods with label app=frontend.

Kubernetes

affinity:
  podAffinity:
    requiredDuringSchedulingIgnoredDuringExecution:
    - labelSelector:
        matchExpressions:
        - key: app
          operator: In
          values:
          - [1]
      topologyKey: kubernetes.io/hostname

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

Abackend

Bfrontend

Cdatabase

Dcache

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a label value that does not match the target pods.

Confusing pod affinity with pod anti-affinity.

The pod affinity requires pods with label app=frontend, so the value must be frontend.

2fill in blank

medium

Complete the code to specify pod anti-affinity to avoid scheduling pods on the same node with label app=database.

Kubernetes

affinity:
  podAntiAffinity:
    requiredDuringSchedulingIgnoredDuringExecution:
    - labelSelector:
        matchLabels:
          app: [1]
      topologyKey: kubernetes.io/hostname

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

Acache

Bfrontend

Cdatabase

Dworker

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong label value that does not match the pods to avoid.

Mixing up pod affinity and anti-affinity.

Pod anti-affinity avoids scheduling pods on nodes with pods labeled app=database, so the value must be database.

3fill in blank

hard

Fix the error in the pod affinity configuration by completing the missing operator.

Kubernetes

affinity:
  podAffinity:
    requiredDuringSchedulingIgnoredDuringExecution:
    - labelSelector:
        matchExpressions:
        - key: role
          operator: [1]
          values:
          - frontend
      topologyKey: failure-domain.beta.kubernetes.io/zone

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

AIn

BExists

CNotIn

DDoesNotExist

Attempts:

3 left

💡 Hint

Common Mistakes

Using Exists or DoesNotExist when values are specified.

Using NotIn which negates the match.

The operator In is used to match pods whose label role is in the specified values list.

4fill in blank

hard

Fill both blanks to create a pod anti-affinity rule that avoids pods with label tier=backend on the same node.

Kubernetes

affinity:
  podAntiAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - weight: 100
      podAffinityTerm:
        labelSelector:
          matchExpressions:
          - key: tier
            operator: [1]
            values:
            - [2]
        topologyKey: kubernetes.io/hostname

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

AIn

Bbackend

Cfrontend

DNotIn

Attempts:

3 left

💡 Hint

Common Mistakes

Using NotIn which would invert the match.

Using the wrong tier value.

The operator In is used with the value backend to specify pods with label tier=backend for anti-affinity.

5fill in blank

hard

Fill all three blanks to define pod affinity that prefers pods with label env=prod and role=frontend on the same zone.

Kubernetes

affinity:
  podAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - weight: 50
      podAffinityTerm:
        labelSelector:
          matchExpressions:
          - key: env
            operator: [1]
            values:
            - [2]
          - key: role
            operator: [3]
            values:
            - frontend
        topologyKey: failure-domain.beta.kubernetes.io/zone

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

AIn

Bprod

DNotIn

Attempts:

3 left

💡 Hint

Common Mistakes

Using NotIn which would exclude the desired pods.

Mixing operator types between the two label selectors.

Both operators are In to match the values prod for env and frontend for role.