Core: Expose getUrlForApp on server side

[stacey-gammon]

This would be useful for moving the url generators to server side, to support alerting and chat ops use cases.

At minimum I need the basePath.

#59453

Any thoughts on whether this would be doable/easy?

[elasticmachine]

Pinging @elastic/kibana-platform (Team:Platform)

[joshdover]

Currently this is not possible because all of the applications are registered in client-side code. The server does not have any knowledge of which applications exist.

This has simplified most things, but it has also made other things a bit tricky. For instance, if a application needs to be mounted on a non-standard route (a route without the /app prefix), they currently have to register a backend route that renders the core bundle as well.

Having knowledge about the applications that exist would eliminate this requirement. However, thus far this use-case isn't very common and it hasn't been much of a headache.

For the alerting use case, could we not have a generic endpoint that accepts an application ID along with some parameters that then gets used to redirect to the corresponding application once the frontend boots up.

A flow like this is what I'm imagining:

• Alert fires a notification with a URL like https://mykibana.com/app/open?app=apm&param1=foo&param2=bar
• Kibana backend serves up the regular Core bundle and mounts the "open" app
• The open app calls the appropriate URL generator function for the "apm" app and redirects the user to that app: https://mykibana.com/app/apm...

[stacey-gammon]

Ah, thanks, this sounds very similar to the service @lukeelmers was suggesting. and actually, I think this may greatly simplify things if we do this...