DaemonSet

This DaemonSet manifest deploys an Elasticsearch (Fluentd) logging agent on every node in the cluster, including master nodes. The toleration for node-role.kubernetes.io/master with NoSchedule effect ensures the pod can run on control-plane nodes as well.

controlplane $ cat ds.yaml
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: elasticsearch
  namespace: kube-system
  labels:
    app: elasticsearch
spec:
  selector:
    matchLabels:
      name:  elasticsearch
  template:
    metadata:
      labels:
        name: elasticsearch
    spec:
      tolerations:
      # this toleration is to have the daemonset runnable on master nodes
      # remove it if your masters can't run pods
      - key: node-role.kubernetes.io/master
        effect: NoSchedule
      containers:
      - name: elasticsearch
        image: k8s.gcr.io/fluentd-elasticsearch:1.20