feat (aws-lambda): Write multiasset function to select diffrent folders as lambda asset

packages/@aws-cdk/aws-lambda/lib/code.ts

@@ -4,6 +4,7 @@ import * as iam from '@aws-cdk/aws-iam';
 import * as s3 from '@aws-cdk/aws-s3';
 import * as s3_assets from '@aws-cdk/aws-s3-assets';
 import * as cdk from '@aws-cdk/core';
+import { zipDirectories } from './private/archive';
 import { Construct } from 'constructs';
 
 /**
@@ -54,6 +55,18 @@ export abstract class Code {
     return new AssetCode(path, options);
   }
 
+    /**
+   * Loads the function code from local disk paths.
+   *
+   * @param paths an array of directories with the Lambda code bundle
+   */
+     public static async fromMultiAsset(paths: string[], options?: s3_assets.AssetOptions): Promise<AssetCode> {
+      //create a zip file from paths in paths[]
+      const outputFileAddress = './cdk.out/directories.zip';
+      await zipDirectories(paths, outputFileAddress);
+      return new AssetCode(outputFileAddress, options);
+    }
+
   /**
    * Loads the function code from an asset created by a Docker build.
    *

packages/@aws-cdk/aws-lambda/lib/private/archive.ts

@@ -0,0 +1,48 @@
+import { createWriteStream, promises as fs } from 'fs';
+import * as path from 'path';
+import * as glob from 'glob';
+
+// namespace object imports won't work in the bundle for function exports
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+const archiver = require('archiver');
+
+export function zipDirectories(directories: string[], outputFile: string): Promise<void> {
+  return new Promise(async (ok, fail) => {
+
+    const output = createWriteStream(outputFile);
+
+    const archive = archiver('zip');
+    archive.on('warning', fail);
+    archive.on('error', fail);
+
+    // archive has been finalized and the output file descriptor has closed, resolve promise
+    // this has to be done before calling `finalize` since the events may fire immediately after.
+    // see https://www.npmjs.com/package/archiver
+    output.once('close', ok);
+
+    archive.pipe(output);
+    for (const directory of directories) {
+      // The below options are needed to support following symlinks when building zip files:
+      // - nodir: This will prevent symlinks themselves from being copied into the zip.
+      // - follow: This will follow symlinks and copy the files within.
+      const globOptions = {
+        dot: true,
+        nodir: true,
+        follow: true,
+        cwd: directory,
+      };
+      const files = glob.sync('**', globOptions); // The output here is already sorted
+      // Append files serially to ensure file order
+      for (const file of files) {
+        const fullPath = path.resolve(directory, file);
+        const [data, stat] = await Promise.all([fs.readFile(fullPath), fs.stat(fullPath)]);
+        archive.append(data, {
+          name: file,
+          date: new Date('1980-01-01T00:00:00.000Z'), // reset dates to get the same hash for the same content
+          mode: stat.mode,
+        });
+      }
+    }
+    await archive.finalize();
+  });
+}

packages/@aws-cdk/aws-lambda/package.json

@@ -117,6 +117,7 @@
     "@aws-cdk/core": "0.0.0",
     "@aws-cdk/cx-api": "0.0.0",
     "@aws-cdk/region-info": "0.0.0",
+    "@types/archiver": "^5.3.1",
     "constructs": "^10.0.0"
   },
   "homepage": "https://github.com/aws/aws-cdk",