Index cleanup API support

Change Type:

• Feature
• Bugfix
• Refactoring

Context and Scope

There is no functionality to drop obsolete and stale indices in core module.

Decision

• Implement cleanupIndices endpoint in Indexer service (see !16 (closed) as example)
• Add indexes clean-up in Storage service, when Kind was deleted.

Rational

This change will keep our Elasticsearch indices clean and healthy. Without it, we are forced to monitor Elasticsearch and manually delete all test and stale indices.

This is also affecting our performance. Because of frequent tests, a lot of indices are being created and not deleted. It causes a raise of callback time. With indices cleanup functionality we could avoid that.

Consequences

We should add this functionality support in every method where there is an index/kind deletion