This commit introduces a module for Kibana that exposes REST APIs that
will be used by Kibana for access to its system indices. These APIs are wrapped
versions of the existing REST endpoints. A new setting is also introduced since
the Kibana system indices' names are allowed to be changed by a user in case
multiple instances of Kibana use the same instance of Elasticsearch.
Additionally, the ThreadContext has been extended to indicate that the use of
system indices may be allowed in a request. This will be built upon in the future
for the protection of system indices.
Backport of #52385
This commit deprecates the creation of dot-prefixed index names (e.g.
.watches) unless they are either 1) a hidden index, or 2) registered by
a plugin that extends SystemIndexPlugin. This is the first step
towards more thorough protections for system indices.
This commit also modifies several plugins which use dot-prefixed indices
to register indices they own as system indices, and adds a plugin to
register .tasks as a system index.
Ryan Ernst
Jay Modi
Gordon Brown