Rollover - min_docs condition

[petardz]

Is your feature request related to a problem? Please describe.
Currently Rollover API supports maxAge, maxSize and maxDocs conditions. When maxAge condition is used we could easily get in situation where index is rolled over, even tho it had 0 or very few documents.

Describe the solution you'd like
Add minDocs condition, which would prevent rollover until specified number of documents is present in index.

Describe alternatives you've considered
call Search API to count documents in index, before calling Rollover API.

Additional context
Alerting, SA and ISM plugins are using rollover API in its "index management job" logic for some plugin indices.

[shinbay-almaz]

Hello, OpenSearch!
I would like to work on this issue. Can you assign it to me, please?

[shinbay-almaz]

While reviewing the code of MaxDocsCondition, I noticed that it returns true when the index have at least specified number of docs, which minDocs condition is intended to do. Did I correctly understand the code?