DevOps Classroom notes 08/Jan/2026

Daemonsets

• Refer Here
• Daemonset ensure a pod is schedule on every node (on subset of nodes)
• Daemonsets support rollingupdates
• Lets run a daemonset with alpine pod with sleep 1d
• Daemonset generally run agent kind of applications (log agent, sync agents)

---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: example-1
spec:
  minReadySeconds: 2
  selector:
    matchLabels:
      app: logagent
  template:
    metadata:
      labels:
        app: logagent
    spec:
      containers:
        - name: logagent
          image: alpine:latest
          command:
            - sleep
            - "3600s"

Jobs and Cron Jobs

• Refer Here for cron job and Refer Here for cron job

Example

• Lets write a cron job which runs container for 20 seconds and should be repeated every minute

---
apiVersion: batch/v1
kind: CronJob
metadata:
  name: example-1
spec:
  schedule: '* * * * *'
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: hello
            image: alpine:latest
            args:
             - sleep
             - "10s"
          restartPolicy: OnFailure

Namespace

• Namespaces act as virtual clusters
• names of resources have to be unique within namespaces
• in k8s we have resources which have two scpes
  • cluster scope
  • namespace scope
• The default namespace is default
• We can use namespaces for environments or applications or any logical organization