Allow multiple .kibana indexes

[aturetta]

With the K3 codebase it was not difficult to use one unique kibana setup for every user. It was a matter of crafting a few rewrites in a proxy.

Now the kibana.index property is a single string used in various source files, and changing the index name at the HTTP level is not enough to allow different sets of users to see their own configurations, because there are multiple server-side validations against the kibana.index value.

I don't mean this in a 'security' point of view.
We have different teams, working on multiple apps each. The apps logs go to a common index, so I'm not worried about security.
It's simply annoying that every user must see the saved objects of all other users, and they rapidly reach a large number.

Even with Shield, each user would see their own indexes, but share .kibana settings.

I think providing a mean to specify an index pattern, instead of a plain string, would be useful. As would the ability to use some externally-provided key to calculate the actual index name at runtime.

[SJovic777]

+1

[trevan]

This can actually be done as a plugin. I was going to put it in my oauth2 plugin but I could create a separate plugin that works for any auth plugin to manage which user gets which kibana index.

[rashidkpc]

As this deals with separation of stored objects, please see #4453