ntp: add config to filter and set ntp interfaces

[Pavan-Gunda]

What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespaces from that line:

/kind api-change
/kind bug
/kind cleanup
/kind design
/kind documentation
/kind failing-test
/kind flake

/kind feature

What this PR does / why we need it:
It makes ntp interfaces configurable
Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

Added a config option to filter ntp interfaces

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: Pavan-Gunda / name: Pavan Gunda (1b67ecf, 4756ae4)

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[cyclinder]

/ok-to-test

[cyclinder]

It's risky. ens3 is an exact NIC name and is not applicable in most scenarios. I prefer to comment them out and suggest that when ntp_filter_interface is true, we should update the value of ntp_interfaces to match the node's NIC name.

But, do you think this still works for scenarios with inconsistent NIC names per node?

[Pavan-Gunda]

Sure! I will comment out the ntp_interfaces section and add your suggestion as a comment.

When having inconsistent NIC names per node, One can have all interfaces from all nodes listed under this list of interfaces and if the interface does not exist on a node, I did a quick test and NTP simply just listens on the set of interfaces that do exist.

interface listen ens3
interface listen test

The ntp server logs looked something like this when I restarted the service

systemd[1]: Started Network Time Service.
ntpd[252818]: proto: precision = 0.050 usec (-24)
ntpd[252818]: restrict: 'monitor' cannot be disabled while 'limited' is enabled
ntpd[252818]: Listen normally on 0 lo 127.0.0.1:123
ntpd[252818]: Listen normally on 1 ens3 xx.xx.xx.xx:123
ntpd[252818]: Listen normally on 2 lo [::1]:123
ntpd[252818]: Listen normally on 3 ens3 [xxx.xxx.xxx.xxx]:123
ntpd[252818]: Listen normally on 4 ens3 [xxx.xxx.xxx.xxx]:123
ntpd[252818]: Listening on routing socket on fd #21 for interface updates

[cyclinder]

Hi @Pavan-Gunda , It looks like the ntp_interfaces section is still not commented out. Is that right?

[Pavan-Gunda]

Hi!

I commented ntp_interfaces section out now. :)

[yankay]

# Some comments
{% for item in ntp_interfaces %}
interface {{ item }}
{% endfor %}

[yankay]

HI @Pavan-Gunda

Because there is only one variable that needs to be config, so

# Some comments
# Uncomment `ntp_interfaces` if enable xxxx
# ntp_interfaces: 
#   - ignore wildcard
#   - isten xxx

Which Can be easier for the code.

[Pavan-Gunda]

Thank you 👍

I made the change now and pushed the code :)

[yankay]

Thanks @Pavan-Gunda
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Pavan-Gunda, yankay

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[Pavan-Gunda]

Hi @cyclinder and @yankay

This pull request apparently also requires an LGTM label for me to be able to merge this. Can I get some help with that :)

[cyclinder]

Thanks @Pavan-Gunda!

/lgtm