need new platform plugin access to kibana.index config value currently available in legacy plugins

[pmuellr]

For the Make it Action project, we're adding a new index to be managed by Kibana to store "events" that have occurred with alerts and actions. Current plan is to name this index .kibana-event-log (and there are other resources like an index template and ilm policy, will be using the same .kibana-event-log prefix.

For legacy plugins, this value is available as config.get('kibana.index'), however this config value does not appear to be available in new platform plugins (np plugins only see their own config). Guessing this would be made available by some core or platform API, or perhaps another NP plugin, any of which is fine.

[elasticmachine]

Pinging @elastic/kibana-platform

[rudolf]

Based on the discussion in #46705 it seems to make sense to expose the kibana. config namespace as a global configuration namespace available to all plugins. Since we expose the config to plugins through PluginInitializerContext it probably makes sense to also expose the kibana config values here:

export interface PluginInitializerContext<ConfigSchema = unknown> {
  opaqueId: PluginOpaqueId;
  env: { mode: EnvironmentMode };
  logger: LoggerFactory;
  config: {
    /* Global configuration from the 'kibana' configPath */
    kibana$: Observable<KibanaConfigSchema>;
    create: <T = ConfigSchema>() => Observable<T>;
    createIfExists: <T = ConfigSchema>() => Observable<T | undefined>;
  };
}

[mshustov]

@rudolf what other "kibana-wide" config values we will provide there?

[rudolf]

These are all the current values, we know kibana.enabled isn't needed anymore so we can filter that out, but I think we have to include all the other values until we've decided what to do with our kibana.yml refactor in #46705:

kibana.enabled (should be removed)
kibana.defaultAppId
kibana.index move into saved objects domain as saved_objects.index
kibana.disableWelcomeScreen
kibana.autocompleteTerminateAfter
kibana.autocompleteTimeout

[mshustov]

I'm curious about path.data as well. Does it belong to a particular domain?

[rudolf]

It seems like path.data is only used for the optimizer and storing a uuid file. If we move uuid to core #48956 there might not be a need to expose this to any other plugins?

But I can imagine that path.data could be useful to other plugins and it would make sense to expose it from the same location.

[mshustov]

@rudolf plugins might want to store their artifacts somewhere in path.data. I can see that reporting and code plugins use this parameter as well.

[lukasolson]

We also need access to the elasticsearch.shardTimeout in the data plugin. Alternatively, the elasticsearch plugin could be responsible for applying that value as the timeout in all search requests.

[joshdover]

We discussed this in our Platform Weekly meeting today and decided to move forward with providing a non-optimal but quick solution for now:

• Expose any globally needed config values on single observable on PluginInitializerContext for 7.x (similar to @rudolf's suggestion above)
• Mark this observable as deprecated and make it obvious in the naming that this will go away.
• Move these global configs to the appropriate services as part of [New Platform] 8.0 Refactor kibana.yml #46705 and remove the globally exposed config.

This will allow us to move quickly during the migration period so that we can reduce the number of decisions that need to be made right now by having one place where we can add any other needed global config keys.

Example

export interface PluginInitializerContext<ConfigSchema = unknown> {
  opaqueId: PluginOpaqueId;
  env: { mode: EnvironmentMode };
  logger: LoggerFactory;
  config: {
    /**
     * Global configuration
     * Note: naming not final here, do we have any existing convention for naming deprecated properties?
     * @deprecated
     */
    globalConfig__deprecated$: Observable<GlobalConfigSchema>;
    create: <T = ConfigSchema>() => Observable<T>;
    createIfExists: <T = ConfigSchema>() => Observable<T | undefined>;
  };
}