Filter on IP version (IPv4 / IPv6)

[kaworu]

Currently it is not possible to filter only IPv4 or IPv6 flows with the CLI.

Note that FlowFilter lack support for this, so a first step will be to add this filter to the Hubble observer at https://github.com/cilium/cilium. There are many example of filters, see https://github.com/cilium/cilium/blob/master/pkg/hubble/filters.

Then, the flow protobuf must be adapted with a new IPVersion field in FlowFilter so that queries can use the new filter.

Finally, a CLI change adding -4|--ipv4 and -6|--ipv6 could make use of this new filter. The option names could be different, although the one proposed in this issue are already widely adopted (see nc(1), curl(1) etc.)

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Parts:

• Server side hubble/filter: filters based on ip version cilium#14556
• Client side

[nyrahul]

Is there an issue in cilium to handle this? If yes, I can take it up. I recently added tcp-flags filter which required updating FlowFilter and thus have an understanding of what needs to be done.

[gandro]

Is there an issue in cilium to handle this? If yes, I can take it up. I recently added tcp-flags filter which required updating FlowFilter and thus have an understanding of what needs to be done.

That would be awesome! 🚀

I don't believe there is a tracking issue on the server side, but it's probably also not needed. Feel free to just create a PR against Cilium with the required filter and API additions referencing this issue!

I have preliminarily assigned you to the issue to avoid other people accidentally taking this one. Do not hesitate un-assign yourself if anything comes up.

[kaworu]

@nyrahul thanks for picking this up! Although I expect this to be easier than the TCP flags, don't hesitate to ping us on Slack if you have any question.

[nyrahul]

@kaworu, @gandro, the issue got closed due to PR merge of cilium-side (server-side) changes. The hubble side changes are still pending. Should this be reopened?