Esm import support

nodejs/build-layer.sh

@@ -15,6 +15,7 @@ npm exec node-prune
 
 echo "Preparing Splunk layer"
 cp nodejs-otel-handler ./build/
+cp loader.mjs ./build/
 cp ../scripts/* ./build/
 mkdir -p build/nodejs
 mv node_modules ./build/nodejs/
@@ -27,7 +28,11 @@ find . \( -name "*.map" -o -name "*.ts" \) -type f -delete
 # remove PACKAGES (CAREFUL!)
 rm -rf ./nodejs/node_modules/graphql ./nodejs/node_modules/bson
 # remove various folders (modules, protobuf definitions)
-find . \( -name "protos" -o -name "esm" \) -type d -prune -exec rm -rf {} \;
+find . -name "protos" -type d -prune -exec rm -rf {} \;
+find . -name "esm" -type d \
+  -not -path "./nodejs/node_modules/import-in-the-middle/*" \
+  -not -path "./nodejs/node_modules/require-in-the-middle/*" \
+  -prune -exec rm -rf {} \;
 # optimize PROTOBUF
 find . -path "./nodejs/node_modules/protobufjs/*" \( -name "bin" -o -name "cli" -o -name "dist" -o -name "scripts" \) -type d -prune -exec rm -rf {} \;
 # optimize SPLUNK

nodejs/loader.mjs

@@ -0,0 +1,101 @@
+import * as module from 'module';
+import * as path from 'path';
+import * as fs from 'fs';
+
+function _hasFolderPackageJsonTypeModule(folder) {
+  if (folder.endsWith('/node_modules')) {
+    return false;
+  }
+  const pj = path.join(folder, '/package.json');
+  if (fs.existsSync(pj)) {
+    try {
+      const pkg = JSON.parse(fs.readFileSync(pj).toString());
+      if (pkg) {
+        if (pkg.type === 'module') {
+          return true;
+        } else {
+          return false;
+        }
+      }
+    } catch (e) {
+      console.warn(`${pj} cannot be read, it will be ignored for ES module detection purposes.`, e);
+      return false;
+    }
+  }
+  if (folder === '/') {
+    return false;
+  }
+  return _hasFolderPackageJsonTypeModule(path.resolve(folder, '..'));
+}
+
+function _hasPackageJsonTypeModule(file) {
+  const jsPath = file + '.js';
+  if (fs.existsSync(jsPath)) {
+    return _hasFolderPackageJsonTypeModule(path.resolve(path.dirname(jsPath)));
+  }
+  return false;
+}
+
+function _resolveHandlerFileName() {
+  const taskRoot = process.env.LAMBDA_TASK_ROOT;
+  const handlerDef = process.env._HANDLER;
+  if (!taskRoot || !handlerDef) {
+    return null;
+  }
+  const handler = path.basename(handlerDef);
+  const moduleRoot = handlerDef.substr(0, handlerDef.length - handler.length);
+  const [module] = handler.split('.', 2);
+  return path.resolve(taskRoot, moduleRoot, module);
+}
+
+function _isHandlerAnESModule() {
+  try {
+    const handlerFileName = _resolveHandlerFileName();
+    if (!handlerFileName) {
+      return false;
+    }
+    if (fs.existsSync(handlerFileName + '.mjs')) {
+      return true;
+    } else if (fs.existsSync(handlerFileName + '.cjs')) {
+      return false;
+    } else {
+      return _hasPackageJsonTypeModule(handlerFileName);
+    }
+  } catch (e) {
+    console.error('Unknown error occurred while checking whether handler is an ES module', e);
+    return false;
+  }
+}
+
+function _isSupportedNodeForEsmLoaderHook() {
+  try {
+    const nodeVersion = process.versions && process.versions.node;
+    if (!nodeVersion) {
+      return false;
+    }
+    const [majorStr, minorStr] = nodeVersion.split('.', 3);
+    const major = Number.parseInt(majorStr, 10);
+    const minor = Number.parseInt(minorStr, 10);
+    if (!Number.isFinite(major) || !Number.isFinite(minor)) {
+      return false;
+    }
+    return major > 20 || (major === 20 && minor >= 6);
+  } catch {
+    return false;
+  }
+}
+
+let registered = false;
+
+export function registerLoader() {
+  if (!registered) {
+    if (_isSupportedNodeForEsmLoaderHook() && typeof module.register === 'function') {
+      module.register('import-in-the-middle/hook.mjs', import.meta.url);
+    }
+    registered = true;
+  }
+}
+
+if (_isHandlerAnESModule()) {
+  registerLoader();
+}

nodejs/nodejs-otel-handler

@@ -1,7 +1,17 @@
 #!/bin/bash
 source /opt/splunk-default-config
 
-export NODE_OPTIONS="${NODE_OPTIONS} --require /opt/wrapper.js"
+node_version="$(node -p "process.versions.node" 2>/dev/null || echo "")"
+node_major="${node_version%%.*}"
+node_minor="${node_version#*.}"
+node_minor="${node_minor%%.*}"
+
+if [[ "$node_major" =~ ^[0-9]+$ ]] && [[ "$node_minor" =~ ^[0-9]+$ ]] && { [ "$node_major" -gt 20 ] || { [ "$node_major" -eq 20 ] && [ "$node_minor" -ge 6 ]; }; }
+then
+  export NODE_OPTIONS="${NODE_OPTIONS} --import /opt/loader.mjs --require /opt/wrapper.js"
+else
+  export NODE_OPTIONS="${NODE_OPTIONS} --require /opt/wrapper.js"
+fi
 
 if [[ $OTEL_RESOURCE_ATTRIBUTES != *"service.name="* ]]; then
   export OTEL_RESOURCE_ATTRIBUTES="service.name=${AWS_LAMBDA_FUNCTION_NAME},${OTEL_RESOURCE_ATTRIBUTES}"