fix(resource): use dynamic import over require to improve ESM compliance

CHANGELOG.md

@@ -60,6 +60,7 @@ For semantic convention package changes, see the [semconv CHANGELOG](packages/se
 ### :bug: (Bug Fix)
 
 * fix(sdk-metrics): do not export from `PeriodicExportingMetricReader` when there are no metrics to export. [#5288](https://github.com/open-telemetry/opentelemetry-js/pull/5288) @jacksonweber
+* fix(resource): use dynamic import over require to improve ESM compliance [#5298](https://github.com/open-telemetry/opentelemetry-js/pull/5298) @xiaoxiangmoe
 
 ### :books: (Refine Doc)
 

packages/opentelemetry-resources/src/detectors/platform/node/machine-id/getMachineId.ts

@@ -15,23 +15,28 @@
  */
 import * as process from 'process';
 
-let getMachineId: () => Promise<string>;
+let getMachineIdImpl: undefined | (() => Promise<string>);
 
-switch (process.platform) {
-  case 'darwin':
-    ({ getMachineId } = require('./getMachineId-darwin'));
-    break;
-  case 'linux':
-    ({ getMachineId } = require('./getMachineId-linux'));
-    break;
-  case 'freebsd':
-    ({ getMachineId } = require('./getMachineId-bsd'));
-    break;
-  case 'win32':
-    ({ getMachineId } = require('./getMachineId-win'));
-    break;
-  default:
-    ({ getMachineId } = require('./getMachineId-unsupported'));
-}
+export async function getMachineId(): Promise<string> {
+  if (!getMachineIdImpl) {
+    switch (process.platform) {
+      case 'darwin':
+        getMachineIdImpl = (await import('./getMachineId-darwin.js')).getMachineId;
+        break;
+      case 'linux':
+        getMachineIdImpl = (await import('./getMachineId-linux.js')).getMachineId;
+        break;
+      case 'freebsd':
+        getMachineIdImpl = (await import('./getMachineId-bsd.js')).getMachineId;
+        break;
+      case 'win32':
+        getMachineIdImpl = (await import('./getMachineId-win.js')).getMachineId;
+        break;
+      default:
+        getMachineIdImpl = (await import('./getMachineId-unsupported.js')).getMachineId;
+        break;
+    }
+  }
 
-export { getMachineId };
+  return getMachineIdImpl();
+}