Skip to main content

DaemonSets

A DaemonSet ensures that a copy of a Pod runs on all (or a subset of) nodes in the cluster.

  • When a new node is added to the cluster, the DaemonSet automatically schedules a Pod on it
  • When a node is removed, the Pod is garbage collected
  • Deleting a DaemonSet removes all the Pods it created
More Information

Example​

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: fluentd
spec:
  selector:
    matchLabels:
      name: fluentd
  template:
    metadata:
      labels:
        name: fluentd
    spec:
      containers:
      - name: fluentd
        image: fluentd:latest

Use Cases​

  • Log collection agents (Fluentd, Filebeat)
  • Monitoring agents (Prometheus Node Exporter, Datadog)
  • Network plugins (Calico, Cilium)
  • Storage daemons (Ceph, GlusterFS)

Running on Specific Nodes​

  • Use nodeSelector or nodeAffinity to schedule the DaemonSet only on specific nodes
  • Use tolerations to run on tainted nodes (e.g. control-plane nodes)
spec:
  template:
    spec:
      nodeSelector:
        role: monitoring
      tolerations:
      - key: node-role.kubernetes.io/control-plane
        effect: NoSchedule
More Information