A daemon is a software process that runs continuously in the background without direct user interaction. In Kubernetes, the term describes both Linux background services and critical control-plane processes. section 1.8 section 1.5
Distinguish these Kubernetes uses of daemon:
- A DaemonSet keeps a pod running on each node; kube-proxy and CNI components commonly use this pattern. section 1.8
- kubelet is different: it runs directly as a Linux background process on the node and should not be managed by a DaemonSet. section 1.8
- Control-plane daemons are critical services; production high availability replicates them and uses leader election, while replicated etcd stores redundant cluster state. section 1.5
Verify daemon processes
Run `kubectl get ds -A` to inspect DaemonSets across namespaces. Inspect the node’s host services with `sudo systemctl list-unit-files --type service | grep kubelet -A3 -B3`; start a stopped kubelet with `systemctl start kubelet`. section 1.8
