# 使用 Podman 自建 ntp-server

## 編輯 Dockerfile

* 需要更換允許同步時間的網段

$ nano Dockerfile
FROM registry.suse.com/bci/bci-base:15.5
RUN zypper -n in chrony && \
    echo "server time.google.com iburst" > /etc/chrony.d/pool.conf && \
    # 允許所有人都可以向他校時
    sed -i "25iallow 0.0.0.0/0" /etc/chrony.conf

EXPOSE 123/udp

ENTRYPOINT [ "/usr/sbin/chronyd", "-d", "-s"]

## Build image

$ sudo podman build -t ntp_server:latest .

## 部署 ntp server

$ nano ntp_server.yaml
apiVersion: v1
kind: Pod
metadata:
  labels:
    app: chrony
  name: chrony
spec:
  containers:
  - image: localhost/ntp_server:latest
    name: chrony
    securityContext:
      capabilities:
        add:
        - CAP_SYS_NICE
        - CAP_SYS_RESOURCE
        - CAP_SYS_TIME
  hostNetwork: true
  hostname: ntp-server

$ sudo podman kube play ntp_server.yaml

## 檢查

$ sudo podman ps -a --pod
CONTAINER ID  IMAGE                                    COMMAND     CREATED         STATUS         PORTS       NAMES               POD ID        PODNAME
ab2fc7e93236  localhost/podman-pause:4.4.4-1680004800              39 seconds ago  Up 35 seconds              d709efb8d672-infra  d709efb8d672  chrony
d2a616434c9a  quay.io/hahappyman/ntp_server:latest                 35 seconds ago  Up 35 seconds              chrony-chrony       d709efb8d672  chrony

## 測試校時

* 在 ubuntu server 上安裝 sntp 套件

$ sudo apt update; sudo apt install sntp

$ sntp <ntp server>

$ sntp 10.10.7.20
2025-11-24 14:06:17.507479 (+0800) +0.000181 +/- 0.000256 10.10.7.20 s2 no-leap