• Taint allow a node to repel a set of pods.
• Toleration’s are applied to pods to influence the scheduling of the pods

Tainting a node using kubectl

• kubectl taint nodes NODE_NAME LABEL_KEY:LABEL_VALUE:NoExecute
• remove taint: kubectl taint nodes NODE_NAME LABEL_KEY-
  • adding - after the key will remove the key value from the taints

NoExecute

• the tolerationSeconds will define how long the pods can run on a tainted node before being evicted.

tolerations:
  - key: "KEY"
    operator: "Equal"
    value: "VALUE"
    effect: "NoExecute"
    tolerationSeconds: 300

Few node labels that are tainted:

• node.kubernetes.io/not-ready
• node.kubernetes.io/unreachable
• node.kubernetes.io/out-of-disk
• node.kubernetes.io/memory-pressure
• node.kubernetes.io/disk-pressure
• node.kubernetes.io/network-unavailable
• node.kubernetes.io/unschedulable

Set Tolerance so that it schedules on every node [1]

tolerations:
  - effect: NoSchedule
    operator: Exists

References

[1]: Helm: set tolerations for promtail in loki-stack chart · Issue #2298 · grafana/loki · GitHub