Add warnings to upgrade assistant for search sessions

docs/upgrade-notes.asciidoc

@@ -235,4 +235,26 @@ Systems that use HTTP/1 or don't have TLS configured will get a deprecation warn
 Verify that TLS is properly configured by enabling it and providing valid certificates in the settings. Test your system to ensure that connections are established securely over HTTP/2.
 
 If your Kibana server is hosted behind a load balancer or reverse proxy we recommend testing your deployment configuration before upgrading to 9.0. 
+====
+
+
+[discrete]
+[[known-issue-206998]]
+.Search sessions has been disabled by default (9.0.0)
+[%collapsible]
+====
+*Details* +
+Starting from version 9.0.0, search sessions has been disabled by default. To view, manage, and restore search sessions, the feature needs to be explicitly re-enabled. 
+
+*Impact* +
+Search sessions will be disabled unless they are explicitly enabled in config.yml.
+
+*Action* +
+If you would like to continue using, managing, and restoring search sessions in 9.0, you'll need to re-enable them in your kibana.yml configuration file. If not, no action is necessary.
+
+To re-enable search sessions, add the following in your config.yml:
+
+```
+data.search.sessions.enabled: true
+``` 
 ====

src/platform/plugins/shared/data/server/deprecations/index.ts

@@ -0,0 +1,10 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+export { createSearchSessionsDeprecationsConfig } from './search_sessions';

src/platform/plugins/shared/data/server/deprecations/search_sessions.ts

@@ -0,0 +1,132 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+import type {
+  CoreSetup,
+  DeprecationsDetails,
+  GetDeprecationsContext,
+  RegisterDeprecationsConfig,
+  SavedObjectsFindResult,
+} from '@kbn/core/server';
+import { i18n } from '@kbn/i18n';
+import type { DeprecationDetailsMessage } from '@kbn/core-deprecations-common';
+import { SEARCH_SESSION_TYPE, SearchSessionSavedObjectAttributes } from '../../common';
+
+type SearchSessionAttributes = Pick<
+  SearchSessionSavedObjectAttributes,
+  'name' | 'username' | 'expires'
+>;
+
+export const createSearchSessionsDeprecationsConfig: (
+  core: CoreSetup
+) => RegisterDeprecationsConfig = (core: CoreSetup) => ({
+  getDeprecations: async (context: GetDeprecationsContext): Promise<DeprecationsDetails[]> => {
+    const [coreStart] = await core.getStartServices();
+    const savedObjectsClient = coreStart.savedObjects.getScopedClient(context.request, {
+      includedHiddenTypes: [SEARCH_SESSION_TYPE],
+    });
+    const finder = savedObjectsClient.createPointInTimeFinder<SearchSessionAttributes>({
+      type: 'search-session',
+      perPage: 1000,
+      fields: ['name', 'username', 'expires'],
+      namespaces: ['*'],
+    });
+
+    const searchSessions: Array<SavedObjectsFindResult<SearchSessionAttributes>> = [];
+
+    for await (const response of finder.find()) {
+      searchSessions.push(
+        ...response.saved_objects.filter(
+          (so) => new Date(so.attributes.expires).getTime() > Date.now()
+        )
+      );
+    }
+
+    if (!searchSessions.length) {
+      return [];
+    }
+
+    return [
+      {
+        title: i18n.translate('data.deprecations.searchSessionsTitle', {
+          defaultMessage: 'Found active search sessions',
+        }),
+        message: buildMessage({ searchSessions }),
+        deprecationType: 'feature',
+        level: 'warning',
+        correctiveActions: {
+          manualSteps: [
+            i18n.translate('data.deprecations.searchSessions.manualStepOneMessage', {
+              defaultMessage: 'Open the kibana.yml config file.',
+            }),
+            i18n.translate('data.deprecations.searchSessions.manualStepTwoMessage', {
+              defaultMessage: 'Add the following: "data.search.sessions.enabled: true"',
+            }),
+            i18n.translate('data.deprecations.searchSessions.manualStepTwoMessage', {
+              defaultMessage:
+                'Alternatively, if you do not want to keep these search sessions after upgrade, navigate to Stack Management > Search Sessions and delete any sessions that have not expired.',
+            }),
+          ],
+        },
+      },
+    ];
+  },
+});
+
+const searchSessionIdLabel = i18n.translate(
+  'data.deprecations.searchSessions.searchSessionIdLabel',
+  {
+    defaultMessage: 'ID',
+  }
+);
+
+const searchSessionNameLabel = i18n.translate(
+  'data.deprecations.searchSessions.searchSessionNameLabel',
+  {
+    defaultMessage: 'Name',
+  }
+);
+
+const searchSessionUserLabel = i18n.translate(
+  'data.deprecations.searchSessions.searchSessionUserLabel',
+  {
+    defaultMessage: 'User',
+  }
+);
+
+const searchSessionSpacesLabel = i18n.translate(
+  'data.deprecations.searchSessions.searchSessionSpacesLabel',
+  {
+    defaultMessage: 'Spaces',
+  }
+);
+
+const buildSearchSessionsListEntry = (
+  so: SavedObjectsFindResult<SearchSessionAttributes>
+) => `- **${searchSessionIdLabel}:** ${so.id}
+  - **${searchSessionNameLabel}:** ${so.attributes.name}
+  - **${searchSessionUserLabel}:** ${so.attributes.username}
+  - **${searchSessionSpacesLabel}:** ${so.namespaces?.join(', ')}`;
+
+const buildMessage = ({
+  searchSessions,
+}: {
+  searchSessions: Array<SavedObjectsFindResult<SearchSessionAttributes>>;
+}): DeprecationDetailsMessage => ({
+  type: 'markdown',
+  content: i18n.translate('data.deprecations.scriptedFieldsMessage', {
+    defaultMessage: `The search sessions feature is deprecated and will be disabled by default in 9.0. You currently have {numberOfSearchSessions} active search session(s). If you would like to continue using, managing, and restoring search sessions in 9.0, you'll need to re-enable them in your kibana.yml configuration file. If not, no action is necessary.
+The following is a list of all active search sessions and their associated spaces:
+{searchSessionsList}`,
+    values: {
+      numberOfSearchSessions: searchSessions.length,
+      searchSessionsList: searchSessions.map(buildSearchSessionsListEntry).join('\n'),
+    },
+  }),
+});

src/platform/plugins/shared/data/server/plugin.ts

@@ -12,6 +12,7 @@ import { ExpressionsServerSetup } from '@kbn/expressions-plugin/server';
 import { PluginStart as DataViewsServerPluginStart } from '@kbn/data-views-plugin/server';
 import { UsageCollectionSetup } from '@kbn/usage-collection-plugin/server';
 import { FieldFormatsSetup, FieldFormatsStart } from '@kbn/field-formats-plugin/server';
+import { createSearchSessionsDeprecationsConfig } from './deprecations';
 import { ConfigSchema } from './config';
 import type { ISearchSetup, ISearchStart } from './search';
 import { DatatableUtilitiesService } from './datatable_utilities';
@@ -90,6 +91,7 @@ export class DataServerPlugin
     this.kqlTelemetryService.setup(core, { usageCollection });
 
     core.uiSettings.register(getUiSettings(core.docLinks, this.config.enableUiSettingsValidations));
+    core.deprecations.registerDeprecations(createSearchSessionsDeprecationsConfig(core));
 
     const searchSetup = this.searchService.setup(core, {
       expressions,

src/platform/plugins/shared/data/tsconfig.json

@@ -53,7 +53,8 @@
     "@kbn/search-types",
     "@kbn/safer-lodash-set",
     "@kbn/esql-utils",
-    "@kbn/shared-ux-table-persist"
+    "@kbn/shared-ux-table-persist",
+    "@kbn/core-deprecations-common"
   ],
   "exclude": [
     "target/**/*",