feat(tracing): Add db connection attributes for mysql spans (#8775)

Align mysql spans with
https://github.com/open-telemetry/semantic-conventions/blob/main/docs/database/mssql.md

needed for starfish views.

Author: AbhiPrasad

packages/node-integration-tests/suites/tracing/auto-instrument/mysql/test.ts

@@ -14,6 +14,9 @@ test('should auto-instrument `mysql` package.', async () => {
         op: 'db',
         data: {
           'db.system': 'mysql',
+          'db.user': 'root',
+          'server.address': expect.any(String),
+          'server.port': expect.any(Number),
         },
       },
 
@@ -22,6 +25,9 @@ test('should auto-instrument `mysql` package.', async () => {
         op: 'db',
         data: {
           'db.system': 'mysql',
+          'db.user': 'root',
+          'server.address': expect.any(String),
+          'server.port': expect.any(Number),
         },
       },
     ],

packages/tracing-internal/src/node/integrations/mysql.ts

@@ -6,9 +6,18 @@ import type { LazyLoadedIntegration } from './lazy';
 import { shouldDisableAutoInstrumentation } from './utils/node-utils';
 
 interface MysqlConnection {
+  prototype: {
+    connect: () => void;
+  };
   createQuery: () => void;
 }
 
+interface MysqlConnectionConfig {
+  host: string;
+  port: number;
+  user: string;
+}
+
 /** Tracing integration for node-mysql package */
 export class Mysql implements LazyLoadedIntegration<MysqlConnection> {
   /**
@@ -48,6 +57,32 @@ export class Mysql implements LazyLoadedIntegration<MysqlConnection> {
       return;
     }
 
+    let mySqlConfig: MysqlConnectionConfig | undefined = undefined;
+
+    try {
+      pkg.prototype.connect = new Proxy(pkg.prototype.connect, {
+        apply(wrappingTarget, thisArg: { config: MysqlConnectionConfig }, args) {
+          if (!mySqlConfig) {
+            mySqlConfig = thisArg.config;
+          }
+          return wrappingTarget.apply(thisArg, args);
+        },
+      });
+    } catch (e) {
+      __DEBUG_BUILD__ && logger.error('Mysql Integration was unable to instrument `mysql` config.');
+    }
+
+    function spanDataFromConfig(): Record<string, unknown> {
+      if (!mySqlConfig) {
+        return {};
+      }
+      return {
+        'server.address': mySqlConfig.host,
+        'server.port': mySqlConfig.port,
+        'db.user': mySqlConfig.user,
+      };
+    }
+
     // The original function will have one of these signatures:
     //    function (callback) => void
     //    function (options, callback) => void
@@ -60,6 +95,7 @@ export class Mysql implements LazyLoadedIntegration<MysqlConnection> {
           description: typeof options === 'string' ? options : (options as { sql: string }).sql,
           op: 'db',
           data: {
+            ...spanDataFromConfig(),
             'db.system': 'mysql',
           },
         });