Documentation: config for ingester/distributor memberlist is invalid

[zswanson]

Describe the bug
https://grafana.com/docs/loki/latest/configuration/#ingester_config
https://grafana.com/docs/loki/latest/configuration/#distributor_config

Current documentation for the ingester and distributor config describes the ring config as:

lifecycler:
  ring:
    kvstore:
      # Backend storage to use for the ring. Supported values are: consul, etcd,
      # inmemory, memberlist
      # CLI flag: -ring.store
      [store: <string> | default = "consul"]

      # The prefix for the keys in the store. Should end with a /.
      # CLI flag: -ring.prefix
      [prefix: <string> | default = "collectors/"]

      # The consul_config configures the consul client.
      # CLI flag: <no prefix>
      [consul: <consul_config>]

      # The etcd_config configures the etcd client.
      # CLI flag: <no prefix>
      [etcd: <etcd_config>]

      # Configuration for Gossip memberlist. Only applies if store is "memberlist"
      # CLI flag: <no prefix>
      [memberlist: <memberlist_config>]

The memberlist element in that heirarchy is incorrect, and will cause loki to err at startup with an invalid config. memberlist is actually a root level element and is defined once and then referenced with store: memberlist in the distributor and ingester configurations. While I have not tested it, I imagine the same holds true for consul and etcd configs.

Expected behavior
Documentation should be adjusted to add memberlist as a root element, and remove the definition from the distributor_config and ingester_config sections.

[stale]

This issue has been automatically marked as stale because it has not had any activity in the past 30 days. It will be closed in 7 days if no further activity occurs. Thank you for your contributions.

[komapa]

We had the same problem, the documentation is wrong and seems like it would be great to fix.

[james-callahan]

I ran into this today.

I'm curious which components will have the memberlist port bound and should be listed in join_members. Currently I have:

memberlist:
    join_members:
      - distributor
      - ingester

However I have the suspicion that e.g. querier could be added to that list.

[lmickh]

The distributor, ingester, and querier should all have memberlist configs. Only the ingester will have tokens. The other two will use it to find the ingesters. You can look at the /ring path on the distributor api to see the tokens to verify the all of the ingesters are present.

[stale]

This issue has been automatically marked as stale because it has not had any activity in the past 30 days. It will be closed in 7 days if no further activity occurs. Thank you for your contributions.