Tim Vernum 590777150f
Explicitly fail if a realm only exists in keystore (#45091)
There are no realms that can be configured exclusively with secure
settings. Every realm that supports secure settings also requires one
or more non-secure settings.
However, sometimes a node will be configured with entries in the
keystore for which there is nothing in elasticsearch.yml - this may be
because the realm we removed from the yml, but not deleted from the
keystore, or it could be because there was a typo in the realm name
which has accidentially orphaned the keystore entry.

In these cases the realm building would fail, but the error would not
always be clear or point to the root cause (orphaned keystore
entries). RealmSettings would act as though the realm existed, but
then fail because an incorrect combination of settings was provided.

This change causes realm building to fail early, with an explicit
message about incorrect keystore entries.

Backport of: #44471
2019-08-02 12:28:59 +10:00
..