Hey Julien, I've finished up a *rough *proof of concept for what xDS support in Prometheus could look like [1]. I think it shows the main areas without going too over-the-top. In summary, the two main pieces to the integration seem to be an xDS API definition[2] and an xDS client/ discovery that uses an implementation of this API [3] (HTTP discovery implementation here[4]). For the xDS API, envoy does not have a native concept of metrics/ monitoring, so we need to define this data structure -- I've currently sketched one out (taking from Kuma) that is very close to a targetgroup[5].
A few pros: - support for both HTTP and gRPC API implementations - xDS protocol is well documented - versioned API will make modifications possible A few cons: - complexity of the protocol for people who have not used it - added dependencies on gRPC and envoy + build processes additions for compiling protobuf - xDS adds some overhead for implementors of this API, though this seems like an "advanced" use case where that is ok Please let me know what you think and if you think it's feasible to move forward with xDS or if we should go back to discussions of a simpler HTTP/ gRPC approach. Best, Austin [1]: https://github.com/austince/prometheus/tree/discovery-xds/discovery/xds [2]: https://github.com/austince/prometheus/tree/discovery-xds/discovery/xds#xds-api-implementation [3]: https://github.com/austince/prometheus/tree/discovery-xds/discovery/xds#discovery-scraping [4]: https://github.com/austince/prometheus/blob/discovery-xds/discovery/xds/http_discovery.go [5]: https://github.com/austince/prometheus/blob/discovery-xds/discovery/xds/api/v1alpha1/mads.proto On Saturday, February 6, 2021 at 7:04:21 PM UTC-5 Austin Cawley-Edwards wrote: > Hey Julien, > > Thanks for reaching back out about this. I’ve been on the midst of a job > transition and have not made any progress, but that is finally fully done > and I can try to move this along (though it will still be slowly). I’ll get > back to research and bring it up at the next Kuma community meeting in two > weeks, and then report back. > > Best, > Austin > > On Sat, Feb 6, 2021 at 3:36 PM Julien Pivotto <[email protected]> > wrote: > >> Hello Austin, >> >> Is there any progress here? I am really willing to learn more about xds >> and how it would fit here. >> >> On 29 Oct 11:09, Austin Cawley-Edwards wrote: >> > Perfect, I'll get started collecting that data. Thanks for the >> direction. >> > >> > Best, >> > Austin >> > >> > On Wed, Oct 28, 2020 at 1:07 PM Julien Pivotto <[email protected] >> > >> > wrote: >> > >> > > On 28 Oct 08:28, Austin Cawley-Edwards wrote: >> > > > Hey Julien, >> > > > >> > > > Following up on if you've had time to think about how we can move >> > > forward >> > > > on one of these paths. I haven't been able to find any formal >> proposals >> > > for >> > > > the other recently merged SDs like Eureka besides this comment[1]. >> Would >> > > it >> > > > be valuable for us to work on something similar for envoy's xDS in >> the >> > > > meantime? >> > > >> > > >> > > Let's be honest that recent service discoveries are 'small', and that >> > > big ones are quite old now. >> > > >> > > I still need to gather intel on xDS; but let's start by collecting >> data: >> > > >> > > - What would the configuration look like (does it need multiple >> > > `roles`) >> > > - Which meta labels could we have exposed >> > > - How would we set the address >> > > >> > > That hopefully should not be too much work and then we can see how/if >> we >> > > move forward with this. >> > > >> > > > >> > > > Thanks, >> > > > Austin >> > > > >> > > > [1]: >> > > > >> > > >> https://github.com/prometheus/prometheus/pull/3369#issuecomment-667344846 >> > > > >> > > > On Wednesday, October 21, 2020 at 6:49:59 PM UTC-4 Austin >> Cawley-Edwards >> > > > wrote: >> > > > >> > > > > That makes sense to me, and would be nice to build of an existing >> > > > > protocol, and agree it sounds like a large effort. I’m pretty new >> to >> > > xDS as >> > > > > well, though we have many people on the Kuma team who are quite >> > > > > knowledgeable — I’d be happy to set up a call/ bring them in to >> help >> > > size >> > > > > the work if you’d be open to that. >> > > > > >> > > > > And understand + agree on the configuration approach for the extra >> > > layer. >> > > > > The main difficulty for users is configuring the file_sd + >> sidecar, >> > > > > relabel_configs should be fairly straightforward and accessible. >> > > > > >> > > > > Austin >> > > > > >> > > > > On Wed, Oct 21, 2020 at 6:37 PM Julien Pivotto < >> > > [email protected]> >> > > > > wrote: >> > > > > >> > > > >> On 21 Oct 15:12, Austin Cawley-Edwards wrote: >> > > > >> > Hey all, >> > > > >> > >> > > > >> > I've gathered up some research about our efforts with the DNS >> SD >> > > > >> option, >> > > > >> > please let me know if I've overlooked something. >> > > > >> >> > > > >> I have been looking on my side too - I think that what the option >> > > that's >> > > > >> more likely on the table would not to have a "generic" >> implementation, >> > > > >> but a xDS protocol service discovery. In that case, it would not >> be an >> > > > >> issue to have that in Prometheus (even the gRPC version). >> > > > >> >> > > > >> However, the extra layer that kuma is offering in the SD should >> be >> > > done >> > > > >> at the Prometheus configuration level - e.g. by the user, in the >> > > > >> relabel_configs. >> > > > >> >> > > > >> I think I'd like to better understand xDS but it seems that it >> could >> > > be >> > > > >> good option for a service discovery in Prometheus, at least at >> first >> > > > >> sight. >> > > > >> >> > > > >> We are looking at a huge amount of work here I think. >> > > > >> >> > > > >> -- >> > > > >> Julien Pivotto >> > > > >> @roidelapluie >> > > > >> >> > > > > >> > > > >> > > > -- >> > > > You received this message because you are subscribed to the Google >> > > Groups "Prometheus Developers" group. >> > > > To unsubscribe from this group and stop receiving emails from it, >> send >> > > an email to [email protected]. >> > > > To view this discussion on the web visit >> > > >> https://groups.google.com/d/msgid/prometheus-developers/89922987-42e4-4807-9956-5590cb2de558n%40googlegroups.com >> > > . >> > > >> > > >> > > -- >> > > Julien Pivotto >> > > @roidelapluie >> > > >> > >> > -- >> > You received this message because you are subscribed to the Google >> Groups "Prometheus Developers" group. >> > To unsubscribe from this group and stop receiving emails from it, send >> an email to [email protected]. >> > To view this discussion on the web visit >> https://groups.google.com/d/msgid/prometheus-developers/CALGL%2BUBExJmaD9rzXWnTJf5h6my3cbYrrh-uQjCD9U9PGoW-Aw%40mail.gmail.com >> . >> >> -- >> Julien Pivotto >> @roidelapluie >> > -- You received this message because you are subscribed to the Google Groups "Prometheus Developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/prometheus-developers/7db91c8f-33e2-4253-8cc6-daf596a1d1ban%40googlegroups.com.
