Kubernetes DaemonSet Complete Guide

💡 Quick Answer: deployments

The Problem

This is one of the most searched Kubernetes topics with thousands of monthly searches. A comprehensive, production-ready guide prevents hours of trial and error.

The Solution

Create a DaemonSet

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: node-exporter
  namespace: monitoring
spec:
  selector:
    matchLabels:
      app: node-exporter
  updateStrategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 1      # Update 1 node at a time
  template:
    metadata:
      labels:
        app: node-exporter
    spec:
      tolerations:
        # Run on ALL nodes including control plane
        - operator: Exists
      hostNetwork: true       # Access node network
      hostPID: true           # Access node processes
      containers:
        - name: node-exporter
          image: prom/node-exporter:v1.7.0
          ports:
            - containerPort: 9100
              hostPort: 9100
          resources:
            requests:
              cpu: 50m
              memory: 64Mi
            limits:
              cpu: 200m
              memory: 128Mi
          volumeMounts:
            - name: proc
              mountPath: /host/proc
              readOnly: true
            - name: sys
              mountPath: /host/sys
              readOnly: true
      volumes:
        - name: proc
          hostPath:
            path: /proc
        - name: sys
          hostPath:
            path: /sys

Target Specific Nodes

spec:
  template:
    spec:
      # Only run on GPU nodes
      nodeSelector:
        accelerator: nvidia-gpu
      # Or use affinity for more control
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
              - matchExpressions:
                  - key: node-role.kubernetes.io/worker
                    operator: Exists

Common DaemonSet Use Cases

# Check DaemonSet status
kubectl get ds -n monitoring
# NAME            DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE
# node-exporter   5         5         5       5            5

kubectl rollout status ds/node-exporter -n monitoring

graph TD
    A[DaemonSet: node-exporter] --> B[worker-1: node-exporter pod]
    A --> C[worker-2: node-exporter pod]
    A --> D[worker-3: node-exporter pod]
    E[New node added] -->|Auto-scheduled| F[worker-4: node-exporter pod]
    G[Node removed] -->|Auto-cleaned| H[Pod terminated]

Frequently Asked Questions

DaemonSet vs Deployment with anti-affinity?

DaemonSet guarantees exactly one pod per matching node, auto-scales with node count, and respects node selectors. Using Deployment + anti-affinity is a hack — use DaemonSets for per-node workloads.

How to skip certain nodes?

Use nodeSelector or nodeAffinity to target specific nodes. Or add taints to nodes you want to skip and don’t include matching tolerations in the DaemonSet.

Best Practices

• Start with the simplest configuration that solves your problem
• Test in staging before production
• Use kubectl describe and events for troubleshooting
• Document team conventions for consistency

Key Takeaways

• This is fundamental Kubernetes operational knowledge
• Follow established conventions and recommended labels
• Monitor and iterate based on real production behavior
• Automate repetitive tasks to reduce human error