Kubernetes Daemonsets to fix NTP issue

#alpinecontainer #k8s #daemonset #ntpissue

Problem Description

Recently I keep seeing the NTP issue with my custom AMI images. Some reason chrony daemonsets is not working as expected and seeing the intermittent issue. Possibly some configuration problems.

Solutions:

I decide to write a quick Kubernetes daemonsets to fix this problem. Daemoset is running a simple alpine container. And a while loop while true; do hwclock -s; sleep 86400; done, which basically run hwclock -s command sleep for =24_60_60 seconds = 1 day.

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: ntp-sync
  labels:
    k8s-app: ntp-sync
spec:
  selector:
    matchLabels:
      name: ntp-sync
  template:
    metadata:
      labels:
        name: ntp-sync
    spec:
      tolerations:
      - key: node-role.kubernetes.io/master
        effect: NoSchedule
      containers:
      - name: ntp-sync
        image: alpine
        command: ["/bin/sh"]
        args: ["-c", "while true; do hwclock -s; sleep 86400; done"]
        resources:
          limits:
            memory: 20Mi
            cpu: 20m
          requests:
            cpu: 10m
            memory: 10Mi
        securityContext:
          privileged: true