feat: feat: add ability to load resolved plugin

Author: Richard Cornelissen

packages/opentelemetry-node/README.md

@@ -82,9 +82,12 @@ In the following example:
 - the default express plugin is disabled
 - the http plugin has a custom config for a `requestHook`
 - the customPlugin is loaded from the user supplied path
+- the customPlugin2 is resolved locally and injected
 - all default plugins are still loaded if installed.
 
 ```js
+import {plugin as httpsPlugin} from '@opentelemetry/plugin-https';
+
 const provider = new NodeTracerProvider({
   plugins: {
     express: {
@@ -98,6 +101,9 @@ const provider = new NodeTracerProvider({
     customPlugin: {
       path: "/path/to/custom/module",
     },
+    customPlugin2: {
+      plugin: httpsPlugin,
+    },
   },
 });
 ```

packages/opentelemetry-node/src/instrumentation/PluginLoader.ts

@@ -131,6 +131,7 @@ export class PluginLoader {
         if (this._hookState !== HookState.ENABLED) return exports;
         const config = pluginsToLoad[name];
         const modulePath = config.path!;
+        const modulePlugin = config.plugin;
         let version = null;
 
         if (!baseDir) {
@@ -170,7 +171,7 @@ export class PluginLoader {
 
         // Expecting a plugin from module;
         try {
-          const plugin: Plugin = require(modulePath).plugin;
+          const plugin: Plugin = modulePlugin ?? require(modulePath).plugin;
           if (!utils.isSupportedVersion(version, plugin.supportedVersions)) {
             this.logger.warn(
               `PluginLoader#load: Plugin ${name} only supports module ${plugin.moduleName} with the versions: ${plugin.supportedVersions}`