Remove support for deprecated xpack.telemetry configurations

docs/migration/migrate_8_0.asciidoc

@@ -141,4 +141,13 @@ access level.
 been deprecated with warnings that have been logged throughout 7.x. Please use Kibana UI to re-generate the
 POST URL snippets if you depend on these for automated PDF reports.
 
+[float]
+=== Configurations starting with `xpack.telemetry` are no longer valid
+
+*Details:*
+The `xpack.` prefix has been removed for all telemetry configurations.
+
+*Impact:*
+For any configurations beginning with `xpack.telemetry`, remove the `xpack` prefix. Use {kibana-ref}/telemetry-settings-kbn.html#telemetry-general-settings[`telemetry.enabled`] instead.
+
 // end::notable-breaking-changes[]

docs/settings/telemetry-settings.asciidoc

@@ -0,0 +1,38 @@
+[[telemetry-settings-kbn]]
+=== Telemetry settings in Kibana
+++++
+<titleabbrev>Telemetry settings</titleabbrev>
+++++
+
+By default, Usage Collection (also known as Telemetry) is enabled. This
+helps us learn about the {kib} features that our users are most interested in, so we
+can focus our efforts on making them even better.
+
+You can control whether this data is sent from the {kib} servers, or if it should be sent 
+from the user's browser, in case a firewall is blocking the connections from the server. Additionally, you can decide to completely disable this feature either in the config file or in {kib} via *Management > Kibana > Advanced Settings > Usage Data*.
+
+See our https://www.elastic.co/legal/privacy-statement[Privacy Statement] to learn more.
+
+[float]
+[[telemetry-general-settings]]
+==== General telemetry settings
+
+`telemetry.enabled`:: *Default: true*.
+Set to `true` to send cluster statistics to Elastic. Reporting your
+cluster statistics helps us improve your user experience. Your data is never
+shared with anyone. Set to `false` to disable statistics reporting from any
+browser connected to the {kib} instance.
+
+`telemetry.sendUsageFrom`:: *Default: 'browser'*.
+Set to `'server'` to report the cluster statistics from the {kib} server.
+If the server fails to connect to our endpoint at https://telemetry.elastic.co/, it assumes
+it is behind a firewall and falls back to `'browser'` to send it from users' browsers
+when they are navigating through {kib}.
+
+`telemetry.optIn`:: *Default: true*.
+Set to `true` to automatically opt into reporting cluster statistics. You can also opt out through
+*Advanced Settings* in {kib}.
+
+`telemetry.allowChangingOptInStatus`:: *Default: true*.
+Set to `true` to allow overwriting the `telemetry.optIn` setting via the {kib} UI. 
+Note: When `false`, `telemetry.optIn` must be `true`. To disable telemetry and not allow users to change that parameter, use `telemetry.enabled`.

docs/setup/settings.asciidoc

@@ -463,3 +463,4 @@ include::{docdir}/settings/reporting-settings.asciidoc[]
 include::secure-settings.asciidoc[]
 include::{docdir}/settings/security-settings.asciidoc[]
 include::{docdir}/settings/spaces-settings.asciidoc[]
+include::{docdir}/settings/telemetry-settings.asciidoc[]

src/core/server/config/deprecation/core_deprecations.ts

@@ -128,13 +128,6 @@ export const coreDeprecationProvider: ConfigDeprecationProvider = ({
   renameFromRoot('optimize.lazyHost', 'optimize.watchHost'),
   renameFromRoot('optimize.lazyPrebuild', 'optimize.watchPrebuild'),
   renameFromRoot('optimize.lazyProxyTimeout', 'optimize.watchProxyTimeout'),
-  renameFromRoot('xpack.xpack_main.telemetry.config', 'telemetry.config'),
-  renameFromRoot('xpack.xpack_main.telemetry.url', 'telemetry.url'),
-  renameFromRoot('xpack.xpack_main.telemetry.enabled', 'telemetry.enabled'),
-  renameFromRoot('xpack.telemetry.enabled', 'telemetry.enabled'),
-  renameFromRoot('xpack.telemetry.config', 'telemetry.config'),
-  renameFromRoot('xpack.telemetry.banner', 'telemetry.banner'),
-  renameFromRoot('xpack.telemetry.url', 'telemetry.url'),
   // Monitoring renames
   // TODO: Remove these from here once the monitoring plugin is migrated to NP
   renameFromRoot('xpack.monitoring.enabled', 'monitoring.enabled'),

x-pack/legacy/plugins/xpack_main/index.js

@@ -23,11 +23,6 @@ export const xpackMain = kibana => {
     config(Joi) {
       return Joi.object({
         enabled: Joi.boolean().default(true),
-        telemetry: Joi.object({
-          config: Joi.string().default(),
-          enabled: Joi.boolean().default(),
-          url: Joi.string().default(),
-        }).default(), // deprecated
       }).default();
     },