設定外部 NTP 轉發

本頁說明如何為 Google Distributed Cloud (GDC) 無網路連線裝置設定外部 NTP 重新播放。

只有在裝置中斷連線後，您想將裝置與外部時間同步時，才需要執行這些步驟。

事前準備

如要將設備與外部 NTP 同步，請完成下列步驟：

  1. 開始之前，請確認只有一個 NTP 中繼。如要驗證，請在啟動程序電腦上執行下列指令：

    kubectl get ntprelay -A

    輸出內容如下列範例所示：

    NAMESPACE    NAME           AGE
gpc-system   bi-ntp-relay   4d21h

設定 NTP 轉發

  1. 將啟動程式連線至設備裝置，並判斷連線介面的 IP 位址：

    ifconfig
mgmt: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
    inet 198.18.0.30   netmask 255.255.255.224  broadcast 198.18.0.31
    inet6 fe80::20c:29ff:fea8:fc35  prefixlen 64  scopeid 0x20&lt;link&gt;
...

  2. 編輯 ntprelay CR，將啟動程式管理 IP 納入為上游 IP。

    kubectl edit ntprelay bi-ntp-relay -n gpc-system
ntprelay.system.private.gdc.goog/bi-ntp-relay edited
kubectl get ntprelay bi-ntp-relay -n gpc-system -oyaml

    輸出看起來會像下列範例。在本範例中，upstreamServers 的 IP 位址已變更：

    apiVersion: system.private.gdc.goog/v1alpha1
kind: NTPRelay
metadata:
  creationTimestamp: "2025-05-16T08:44:21Z"
  generation: 2
  name: bi-ntp-relay
  namespace: gpc-system
  resourceVersion: "10871409"
  uid: 6cde8e65-791c-4bc6-9a8b-d5c9bf103f8b
spec:
  upstreamServers:
  - 192.0.2.030

  3. 確認 NTP 同步：

    kubectl get pods -l app.kubernetes.io/name=ntp -n ntp-system -o name | xargs -I {} kubectl exec {} -n ntp-system -- chronyc sources -v; echo

    輸出內容如下：

      .-- Source mode  '^' = server, '=' = peer, '#' = local clock.
/ .- Source state '*' = current best, '+' = combined, '-' = not combined,
| /             'x' = may be in error, '~' = too variable, '?' = unusable.
||                                                 .- xxxx [ yyyy ] +/- zzzz
||      Reachability register (octal) -.           |  xxxx = adjusted offset,
||      Log2(Polling interval) --.      |          |  yyyy = measured offset,
||                                \     |          |  zzzz = estimated error.
||                                 |    |           \
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^* 192.0.2.026                   1   6    17    43   +286ns[  +36us] +/- 1160us
=? 192.0.2.029                 0   6     0     -     +0ns[   +0ns] +/-    0ns
=? 192.0.2.051                 0   6     0     -     +0ns[   +0ns] +/-    0ns
=? 192.0.2.059            0   6     0     -     +0ns[   +0ns] +/-    0ns

  .-- Source mode  '^' = server, '=' = peer, '#' = local clock.
/ .- Source state '*' = current best, '+' = combined, '-' = not combined,
| /             'x' = may be in error, '~' = too variable, '?' = unusable.
||                                                 .- xxxx [ yyyy ] +/- zzzz
||      Reachability register (octal) -.           |  xxxx = adjusted offset,
||      Log2(Polling interval) --.      |          |  yyyy = measured offset,
||                                \     |          |  zzzz = estimated error.
||                                 |    |           \
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^* 192.0.2.026                 1   6    37     2     +2ns[  +90us] +/-   84us
=? 192.0.2.029                 2   6     1     8   +368us[ +449us] +/- 3761us
=? 192.0.2.051                 0   6     1     -     +0ns[   +0ns] +/-    0ns
=? 192.0.2.059                 2   6     1     8   +663us[ +744us] +/-   11ms

  .-- Source mode  '^' = server, '=' = peer, '#' = local clock.
/ .- Source state '*' = current best, '+' = combined, '-' = not combined,
| /             'x' = may be in error, '~' = too variable, '?' = unusable.
||                                                 .- xxxx [ yyyy ] +/- zzzz
||      Reachability register (octal) -.           |  xxxx = adjusted offset,
||      Log2(Polling interval) --.      |          |  yyyy = measured offset,
||                                \     |          |  zzzz = estimated error.
||                                 |    |           \
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^* 192.0.2.026                   1   6    37    29     -6ns[ -759us] +/-   92us
=? 192.0.2.029                   2   6     1    36   +334us[ -346us] +/- 3775us
=? 192.0.2.051                   2   6     1    35   -125us[ -813us] +/- 5839us
=? 192.0.2.059                   0   6     1     -     +0ns[   +0ns] +/-    0ns

  4. 確認 NTP Pod 中的 chronyc 是否參照新加入的 IP。

    kubectl exec -it -n ntp-system ntp2-84ddf7cd99-96vqn -- sh

    輸出內容如下列範例所示：

    Defaulted container "ntp-image" out of: ntp-image, ntp-node-exporter
# chronyc tracking
Reference ID    : C612001E (198.18.0.30)
Stratum         : 2
Ref time (UTC)  : Wed May 21 07:28:38 2025
System time     : 0.000000005 seconds slow of NTP time
Last offset     : +0.000025645 seconds
RMS offset      : 0.000082131 seconds
Frequency       : 15.671 ppm slow
Residual freq   : +0.024 ppm
Skew            : 0.628 ppm
Root delay      : 0.000164273 seconds
Root dispersion : 0.000180630 seconds
Update interval : 64.8 seconds
Leap status     : Normal
# exit