Elasticsearch rest-api-spec is missing the Voting Config Exclusions API

[nkvoll]

Voting Config Exclusions API (https://www.elastic.co/guide/en/elasticsearch/reference/master/voting-config-exclusions.html) was added in 7.0 to support graceful termination of master-eligible nodes.

It seems this API is missing from the REST API spec (https://github.com/elastic/elasticsearch/tree/master/rest-api-spec/src/main/resources/rest-api-spec/api), which means it's not part of the official clients (among potentially other things/tests)

[elasticmachine]

Pinging @elastic/es-distributed (:Distributed/Cluster Coordination)

[elasticmachine]

Pinging @elastic/es-docs (>docs)

[philkra]

Pinging @elastic/es-clients

[jrodewig]

[docs issue triage]

[zacharymorn]

@DaveCTurner I I just finished working on #51412 and this seems like a very similar issue, but just for different REST API. From what I understand this issue is to add:

1. REST API spec
2. A few integration tests.

Is this the right understanding?

[DaveCTurner]

@zacharymorn I've been holding off on taking action here until the changes you've been working on in #50836 have been merged. There's no sense in documenting an API that's immediately deprecated.

[zacharymorn]

@DaveCTurner Sorry I actually just realized that you were assigned to this task. I was browsing for issues to pick up and thought this one might be a good one, as I just finished off a similar one and have been working on #50836, hence the comment above to check for details.

[DaveCTurner]

@zacharymorn now that #50836 is merged would you like to tackle this issue?

[zacharymorn]

@DaveCTurner Thanks for checking! Yes I would love to pick this up.

[zacharymorn]

@DaveCTurner I've opened a PR for this. Please let me know if it looks good.