What are DaemonSets and Jobs in Kubernetes, and when would you use each?

DaemonSets and Jobs are specialized workload controllers for specific use cases beyond regular application deployments.\n\nDaemonSets:\nEnsure a copy of a pod runs on all (or selected) nodes\n• Automatically schedules pods on new nodes\n• Removes pods when nodes are removed\n• Typically used for system-level services\n• Ignores unschedulable nodes by default\n\nDaemonSet Use Cases:\n• Log collection agents (Fluentd, Filebeat)\n• Monitoring agents (Node Exporter, Datadog)\n• Network plugins (Calico, Weave)\n• Storage daemons (Ceph, GlusterFS)\n• Security agents\n\nJobs:\nRun pods to completion for batch processing\n• Ensures specified number of successful completions\n• Handles pod failures and retries\n• Supports parallel execution\n• Cleans up completed pods\n\nJob Types:\n• Job: Run once to completion\n• CronJob: Scheduled recurring jobs\n• Parallel Jobs: Multiple pods running simultaneously\n\nExample DaemonSet:\napiVersion: apps/v1\nkind: DaemonSet\nmetadata:\n name: log-collector\nspec:\n selector:\n matchLabels:\n app: log-collector\n template:\n metadata:\n labels:\n app: log-collector\n spec:\n containers:\n - name: fluentd\n image: fluentd:latest\n volumeMounts:\n - name: varlog\n mountPath: /var/log\n volumes:\n - name: varlog\n hostPath:\n path: /var/log\n\nBest Practices:\n• Use node selectors for targeted deployment\n• Set resource limits for DaemonSet pods\n• Implement proper job cleanup policies\n• Monitor job completion and failure rates\n• Use init containers for setup tasks