[Synthtrace] Support Unstructured Logs (#190864)

closes [3760](https://github.com/elastic/observability-dev/issues/3760)

packages/kbn-apm-synthtrace/src/scenarios/helpers/logs_mock_data.ts

@@ -7,13 +7,30 @@
  */
 
 import { generateShortId } from '@kbn/apm-synthtrace-client';
+import { faker } from '@faker-js/faker';
 import { randomInt } from 'crypto';
+import moment from 'moment';
+
+const {
+  internet: { ipv4, userAgent, httpMethod, httpStatusCode },
+  word: { noun, verb },
+} = faker;
 
 // Utility function to get a random element from an array
 const getAtIndexOrRandom = <T>(values: T[], index?: number) =>
   values[index ?? randomInt(values.length)];
 
 // Arrays for data
+const LOG_LEVELS: string[] = ['FATAL', 'ERROR', 'WARN', 'INFO', 'DEBUG', 'TRACE'];
+
+const JAVA_LOG_MESSAGES = [
+  '[main] com.example1.core.ApplicationCore - Critical failure: NullPointerException encountered during startup',
+  '[main] com.example.service.UserService - User registration completed for userId: 12345',
+  '[main] com.example3.util.JsonParser - Parsing JSON response from external API',
+  '[main] com.example4.security.AuthManager - Unauthorized access attempt detected for userId: 67890',
+  '[main] com.example5.dao.UserDao - Database query failed: java.sql.SQLException: Timeout expired',
+];
+
 const IP_ADDRESSES = [
   '223.72.43.22',
   '20.24.184.101',
@@ -50,3 +67,14 @@ export const getGeoCoordinate = (index?: number) => getAtIndexOrRandom(GEO_COORD
 export const getCloudProvider = (index?: number) => getAtIndexOrRandom(CLOUD_PROVIDERS, index);
 export const getCloudRegion = (index?: number) => getAtIndexOrRandom(CLOUD_REGION, index);
 export const getServiceName = (index?: number) => getAtIndexOrRandom(SERVICE_NAMES, index);
+export const getJavaLog = () =>
+  `${moment().format('YYYY-MM-DD HH:mm:ss,SSS')} ${getAtIndexOrRandom(
+    LOG_LEVELS
+  )} ${getAtIndexOrRandom(JAVA_LOG_MESSAGES)}`;
+
+export const getWebLog = () => {
+  const path = `/api/${noun()}/${verb()}`;
+  const bytes = randomInt(100, 4000);
+
+  return `${ipv4()} - - [${moment().toISOString()}] "${httpMethod()} ${path} HTTP/1.1" ${httpStatusCode()} ${bytes} "-" "${userAgent()}"`;
+};

packages/kbn-apm-synthtrace/src/scenarios/unstructured_logs.ts

@@ -0,0 +1,47 @@
+/*
+ * 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 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 or the Server
+ * Side Public License, v 1.
+ */
+import { LogDocument, log } from '@kbn/apm-synthtrace-client';
+import { Scenario } from '../cli/scenario';
+import { IndexTemplateName } from '../lib/logs/custom_logsdb_index_templates';
+import { withClient } from '../lib/utils/with_client';
+import { parseLogsScenarioOpts } from './helpers/logs_scenario_opts_parser';
+import { getJavaLog, getWebLog } from './helpers/logs_mock_data';
+
+const scenario: Scenario<LogDocument> = async (runOptions) => {
+  const { isLogsDb } = parseLogsScenarioOpts(runOptions.scenarioOpts);
+  return {
+    bootstrap: async ({ logsEsClient }) => {
+      if (isLogsDb) await logsEsClient.createIndexTemplate(IndexTemplateName.LogsDb);
+    },
+    generate: ({ range, clients: { logsEsClient } }) => {
+      const { logger } = runOptions;
+
+      const datasetJavaLogs = (timestamp: number) =>
+        log.create({ isLogsDb }).dataset('java').message(getJavaLog()).timestamp(timestamp);
+
+      const datasetWebLogs = (timestamp: number) =>
+        log.create({ isLogsDb }).dataset('web').message(getWebLog()).timestamp(timestamp);
+
+      const logs = range
+        .interval('1m')
+        .rate(1)
+        .generator((timestamp) => {
+          return Array(200)
+            .fill(0)
+            .flatMap((_, index) => [datasetJavaLogs(timestamp), datasetWebLogs(timestamp)]);
+        });
+
+      return withClient(
+        logsEsClient,
+        logger.perf('generating_logs', () => logs)
+      );
+    },
+  };
+};
+
+export default scenario;