How to get the UUID of a document?

When I am indexing a document to Elasticsearch via Ruby, I am supplying a custom _id field, e.g. analytics-development-foo_18. I get the following response from ES:

{"_index"=>"analytics-development-foo",
 "_id"=>"analytics-development-foo_18",
 "_version"=>5,
 "result"=>"created",
 "_shards"=>{"total"=>2, "successful"=>1, "failed"=>0},
 "_seq_no"=>50,
 "_primary_term"=>12}

Now, when I want to view that document, I head to Discover in Kibana and I can find the document. When I show it in single document view, the URL changes to:

https://kibana.analytics.localhost/app/discover#/doc/e30929a0-d4f4-11ec-9059-552fd0e9601e/analytics-development-foo?id=analytics-development-foo_18&breadcrumb=%23%2F%3F_g%3D(filters%3A!()%2CrefreshInterval%3A(pause%3A!t%2Cvalue%3A0)%2Ctime%3A(from%3A'2022-10-17T18%3A00%3A00.000Z'%2Cto%3A'2022-10-17T19%3A00%3A00.000Z'))%26_a%3D(columns%3A!(_id)%2Cfilters%3A!()%2Cindex%3Ae30929a0-d4f4-11ec-9059-552fd0e9601e%2Cinterval%3Aauto%2Cquery%3A(language%3Akuery%2Cquery%3A'')%2Csort%3A!(!('%40timestamp'%2Cdesc)))

So, the URL contains another ID, a UUID, starting with e30929a0. So, my questions are:

  • What is that UUID?
  • How can I get the UUID of a document when I know its _id only?

Oh, I see now that this is actually the ID of the data view/index pattern to which this document belongs.

(Now, the bonus question would be: if I knew a document _Id, could I programmatically get the data view that corresponds to its index? I know there could be an unlimited number of data views that point to the same document, but just finding the first one would be ideal.)