Node Affinity

Hands-on labs: https://uklabs.kodekloud.com/topic/node-affinity-3/

Assure that pods are running in particular Nodes.

Node Affinity increases the complexity. The previous example with pods.spec.nodeSelector.size: Large would be something like this:

affinity:
  nodeAffinity:
    requiredDuringSchedulingIgnoredDuringExecution:
      nodeSelectorTerms:
        - matchExpressions:
          - key: size
            operator: In
            values:
              - Large

Other possibilities

# Large OR Medium
- key: size
  operator: In
  values:
    - Large
    - Medium
---
# NOT Small
- key: size
  operator: NotIn
  values:
    - Small
---
# label 'size' simply exists, no matter its value
- key: size
  operator: Exists

Node Affinity Types

• requiredDuringSchedulingIgnoredDuringExecution
• preferredDuringSchedulingIgnoredDuringExecution
• requiredDuringSchedulingRequiredDuringExecution (planned to be implemented)