Console UI should not depend on elasticsearch.url

[spalger]

Now that console does not accept a url and has been turned into a devtool it needs to stop relying on the elasticsearchUrl injected var.

Right now, it has to inject the elasticsearch.url configuration value into the default injected vars since the ability to extend the devTools specifically is not provided.

To prevent other applications from becoming dependent on this value, we should remove it use in the console code and from the default injected vars.

[ycombinator]

Note that the elasticsearchUrl var is required by the Console client-side code to generate the curl form of the request.

So while I agree that this var should not be injected via injectDefaultVars to prevent other applications becoming dependent on its value, we will still need some way for the Console client-side code to access this value. When Console was a top-level app, we could've used injectVars (in place of injectDefaultVars) but I'm not sure how to achieve the same effect now.

[spalger]

Interesting, definitely an obstacle

[cjcenizal]

Somewhat relates to #32845.

[jloleysens]

@spalger we are doing some housekeeping with these issues, I just wanted to check with you whether this issue is still relevant with respect to use of "injectedVars". It looks like console now gets this value from CoreSetup.elasticsearch.legacy.config$ where it then extracts the hosts array that was configured in kibana.yml.

This sounds like we have addressed the issue raised here? Possibly that the issue has just taken a different form since this was created 😅 . Let me know what you think!

[EDIT]
Additionally, the front end now gets this value at a specific endpoint from Console.