Add proposal to remove Gossip

[bwplotka]

Additionally fix https://github.com/improbable-eng/thanos/blob/master/docs/getting_started.md#communication-between-components ASAP to stop confusion around which component should talk with which component.

[jdfalk]

Is there a planned replacement or will static addresses be the only option?

[bwplotka]

All will be covered by proposal (:

TL;DR: File SD is planned as a replacement. (Only on querier and ruler, as those only requires such logic)

[tdabasinskas]

It would actually be nice to have support for DNS-based SD, so we could provide a single FQDN, e.g. --store stores.thanos.mycompany.org (which can be under Consul, if needed), for the querier, which would resolve and use all the IP resolved under the DNS name. 🙂

[bwplotka]

Done.

[drax68]

Doesn't seems to be a well thought decision to remove autodiscovery for tool that supposed to be used in dynamic environments like aws with instances going up and down for whatever reason.

[bwplotka]

@drax68 did you have a chance to read the proposal? DNS discovery gives exactly the same dynamicity without massive overhead (and other disadvantage mentioned in document) of gossip protocol (:

Let me know if any other functionality is missing.

[bwplotka]

Proposal completed.