Revert "[Fleet] Improve validation for dynamic Kafka topics" (elastic#219415)

Reverts elastic#212422

We don't want to surface this Beats-specific syntax for dynamic topics
because it greatly harms our ability to migrate users to OTel.

The recommended way to handle complex multi-field interpolations for
topic names is to use an `add_field` Beats processor to add the desired
topic name as a distinct field, and then use that field for the dynamic
topic name in the Fleet-managed Kafka output. I'll be filing a docs
issue to get this in our public docs as well.

Author: kpollich

src/platform/packages/shared/kbn-doc-links/src/get_doc_links.ts

@@ -114,7 +114,6 @@ export const getDocLinks = ({ kibanaBranch, buildFlavor }: GetDocLinkOptions): D
       configuration: `${ELASTIC_WEBSITE_URL}guide/en/beats/filebeat/${DOC_LINK_VERSION}/configuring-howto-filebeat.html`,
       elasticsearchModule: `${ELASTIC_WEBSITE_URL}guide/en/beats/filebeat/${DOC_LINK_VERSION}/filebeat-module-elasticsearch.html`,
       elasticsearchOutput: `${ELASTIC_WEBSITE_URL}guide/en/beats/filebeat/${DOC_LINK_VERSION}/elasticsearch-output.html`,
-      kafkaOutput: `${ELASTIC_WEBSITE_URL}guide/en/beats/filebeat/${DOC_LINK_VERSION}/kafka-output.html`,
       startup: `${ELASTIC_WEBSITE_URL}guide/en/beats/filebeat/${DOC_LINK_VERSION}/filebeat-starting.html`,
       exportedFields: `${ELASTIC_WEBSITE_URL}guide/en/beats/filebeat/${DOC_LINK_VERSION}/exported-fields.html`,
       suricataModule: `${ELASTIC_WEBSITE_URL}guide/en/beats/filebeat/${DOC_LINK_VERSION}/filebeat-module-suricata.html`,
@@ -863,6 +862,7 @@ export const getDocLinks = ({ kibanaBranch, buildFlavor }: GetDocLinkOptions): D
       fleetServerAddFleetServer: `${FLEET_DOCS}add-a-fleet-server.html`,
       settings: `${FLEET_DOCS}fleet-settings.html`,
       kafkaSettings: `${FLEET_DOCS}kafka-output-settings.html`,
+      kafkaOutputTopicsSettings: `${FLEET_DOCS}kafka-output-settings.html#_topics_settings`,
       logstashSettings: `${FLEET_DOCS}ls-output-settings.html`,
       esSettings: `${FLEET_DOCS}es-output-settings.html`,
       settingsFleetServerHostSettings: `${FLEET_DOCS}fleet-settings.html#fleet-server-hosts-setting`,

src/platform/packages/shared/kbn-doc-links/src/types.ts

@@ -71,7 +71,6 @@ export interface DocLinks {
     readonly configuration: string;
     readonly elasticsearchOutput: string;
     readonly elasticsearchModule: string;
-    readonly kafkaOutput: string;
     readonly startup: string;
     readonly exportedFields: string;
     readonly suricataModule: string;
@@ -493,6 +492,7 @@ export interface DocLinks {
     settings: string;
     logstashSettings: string;
     kafkaSettings: string;
+    kafkaOutputTopicsSettings: string;
     settingsFleetServerHostSettings: string;
     settingsFleetServerProxySettings: string;
     troubleshooting: string;

x-pack/platform/plugins/shared/fleet/public/applications/fleet/sections/settings/components/edit_output_flyout/output_form_kafka_topics.tsx

@@ -38,7 +38,7 @@ export const OutputFormKafkaTopics: React.FunctionComponent<{ inputs: OutputForm
   const dynamicOptions: Array<EuiComboBoxOptionOption<string>> = useMemo(() => {
     const options = KAFKA_DYNAMIC_FIELDS.map((option) => ({
       label: option,
-      value: `%{[${option}]}`,
+      value: option,
     }));
     return options;
   }, []);
@@ -78,13 +78,17 @@ export const OutputFormKafkaTopics: React.FunctionComponent<{ inputs: OutputForm
             label={
               <FormattedMessage
                 id="xpack.fleet.settings.editOutputFlyout.kafkaDynamicTopicLabel"
-                defaultMessage="Topic from field(s). For more info, see our {guideLink}"
+                defaultMessage="Topic from field(s). For more info, see our {guideLink}."
                 values={{
                   guideLink: (
-                    <EuiLink href={docLinks.links.filebeat.kafkaOutput} target="_blank" external>
+                    <EuiLink
+                      href={docLinks.links.fleet.kafkaOutputTopicsSettings}
+                      target="_blank"
+                      external
+                    >
                       <FormattedMessage
                         id="xpack.fleet.settings.kafkaGuideLink"
-                        defaultMessage="docs."
+                        defaultMessage="docs"
                       />
                     </EuiLink>
                   ),

x-pack/platform/plugins/shared/fleet/public/applications/fleet/sections/settings/components/edit_output_flyout/output_form_validators.test.tsx

@@ -14,7 +14,6 @@ import {
   validateKafkaHosts,
   validateKibanaURL,
   validateKibanaAPIKey,
-  validateDynamicKafkaTopics,
 } from './output_form_validators';
 
 describe('Output form validation', () => {
@@ -337,28 +336,4 @@ describe('Output form validation', () => {
       ]);
     });
   });
-
-  describe('validateDynamicKafkaTopics', () => {
-    const validTopics = [
-      { label: 'field1', value: '%{[field]}' },
-      { label: 'field2', value: 'field2' },
-      { label: 'field3', value: '%{[field2]}-%{[field3]}' },
-    ];
-    const invalidBracketTopic = [{ label: '%{[field}', value: '%{[field}' }];
-    const invalidPercentTopic = [{ label: '{[field]}', value: '{[field]}' }];
-    it('should work with valid topics', () => {
-      const res = validateDynamicKafkaTopics(validTopics);
-      expect(res).toBeUndefined();
-    });
-    it("should return error with missing brackets in topic's name", () => {
-      const res = validateDynamicKafkaTopics(invalidBracketTopic);
-      expect(res).toEqual([
-        'The topic should have a matching number of opening and closing brackets',
-      ]);
-    });
-    it("should return error with missing percent sign before opening brackets in topic's name", () => {
-      const res = validateDynamicKafkaTopics(invalidPercentTopic);
-      expect(res).toEqual(['Opening brackets should be preceded by a percent sign']);
-    });
-  });
 });

x-pack/platform/plugins/shared/fleet/public/applications/fleet/sections/settings/components/edit_output_flyout/output_form_validators.tsx

@@ -19,15 +19,6 @@ const toSecretValidator =
     return validator(value ?? '');
   };
 
-const getAllIndices = (str: string, substring: string): number[] => {
-  const indices = [];
-  let index = str.indexOf(substring);
-  while (index !== -1) {
-    indices.push(index);
-    index = str.indexOf(substring, index + 1);
-  }
-  return indices;
-};
 export function validateKafkaHosts(value: string[]) {
   const res: Array<{ message: string; index?: number }> = [];
   const urlIndexes: { [key: string]: number[] } = {};
@@ -371,31 +362,12 @@ export function validateKafkaStaticTopic(value: string) {
 export function validateDynamicKafkaTopics(value: Array<EuiComboBoxOptionOption<string>>) {
   const res = [];
   value.forEach((val, idx) => {
-    if (!val || !val.value) {
+    if (!val) {
       res.push(
         i18n.translate('xpack.fleet.settings.outputForm.kafkaTopicFieldRequiredMessage', {
           defaultMessage: 'Topic is required',
         })
       );
-    } else {
-      const openingBrackets = getAllIndices(val.value, '{[');
-      const closingBrackets = getAllIndices(val.value, ']}');
-      if (openingBrackets.length !== closingBrackets.length) {
-        res.push(
-          i18n.translate('xpack.fleet.settings.outputForm.kafkaTopicBracketsError', {
-            defaultMessage:
-              'The topic should have a matching number of opening and closing brackets',
-          })
-        );
-      }
-      // check for preceding percent sign
-      if (!openingBrackets.every((item) => val?.value![item - 1] === '%')) {
-        res.push(
-          i18n.translate('xpack.fleet.settings.outputForm.kafkaTopicPercentError', {
-            defaultMessage: 'Opening brackets should be preceded by a percent sign',
-          })
-        );
-      }
     }
   });
 
@@ -406,7 +378,6 @@ export function validateDynamicKafkaTopics(value: Array<EuiComboBoxOptionOption<
       })
     );
   }
-
   if (res.length) {
     return res;
   }

x-pack/platform/plugins/shared/fleet/public/applications/fleet/sections/settings/components/edit_output_flyout/use_output_form.tsx

@@ -928,7 +928,7 @@ export function useOutputForm(onSucess: () => void, output?: Output, defaultOupu
                   }
                 : kafkaTopicsInput.value === kafkaTopicsType.Dynamic && kafkaDynamicTopicInput.value
                 ? {
-                    topic: kafkaDynamicTopicInput.value,
+                    topic: `%{[${kafkaDynamicTopicInput.value}]}`,
                   }
                 : {}),
               headers: kafkaHeadersInput.value,