Auto import dangling indices #2067
Description
Dangling indices happen when a node that has several indices stored locally, joins a cluster and those local indices do not exists in the cluster metadata. This usually does not happen, especially not with proper gateway.recover_after_nodes flag, but still, users can by mistake get into this state.
A new setting gateway.local.auto_import_dangled setting, with possible values of no (never import dangling indices, but also delay the delation of them), yes (import dangling indices), and closed (import dangling indices, but in closed state). The default value is yes.