chore: experimental cdk migrate command

packages/aws-cdk/lib/cli.ts

@@ -22,6 +22,7 @@ import { CdkToolkit, AssetBuildTime } from '../lib/cdk-toolkit';
 import { realHandler as context } from '../lib/commands/context';
 import { realHandler as docs } from '../lib/commands/docs';
 import { realHandler as doctor } from '../lib/commands/doctor';
+import { cliMigrate } from '../lib/commands/migrate';
 import { RequireApproval } from '../lib/diff';
 import { availableInitLanguages, cliInit, printAvailableTemplates } from '../lib/init';
 import { data, debug, error, print, setLogLevel, setCI } from '../lib/logging';
@@ -269,6 +270,12 @@ async function parseCommandLineArguments(args: string[]) {
       .option('list', { type: 'boolean', desc: 'List the available templates' })
       .option('generate-only', { type: 'boolean', default: false, desc: 'If true, only generates project files, without executing additional operations such as setting up a git repo, installing dependencies or compiling the project' }),
     )
+    .command('migrate', 'Migrate a cloudformation template to cdk', (yargs: Argv) => yargs
+      .option('language', { type: 'string', alias: 'l', desc: 'The language to be used for the new project (default can be configured in ~/.cdk.json)', choices: initTemplateLanguages })
+      .option('inputpath', { type: 'string', alias: 'i', desc: 'The path to the CloudFormation template to migrate' })
+      .option('outputpath', { type: 'string', alias: 'o', desc: 'The output path for the migrated cdk code'})
+      .option('generate-only', { type: 'boolean', default: false, desc: 'If true, only generates project files, without executing additional operations such as setting up a git repo, installing dependencies or compiling the project' }),
+    ) 
     .command('context', 'Manage cached context values', (yargs: Argv) => yargs
       .option('reset', { alias: 'e', desc: 'The context key (or its index) to reset', type: 'string', requiresArg: true })
       .option('force', { alias: 'f', desc: 'Ignore missing key error', type: 'boolean', default: false })
@@ -649,6 +656,9 @@ export async function exec(args: string[], synthesizer?: Synthesizer): Promise<n
         } else {
           return cliInit(args.TEMPLATE, language, undefined, args.generateOnly);
         }
+      case 'migrate':
+        const migrateLanguage = configuration.settings.get(['language']);
+        return cliMigrate(args.inputpath, migrateLanguage, args.generateOnly, argv.outputpath);
       case 'version':
         return data(version.DISPLAY_VERSION);
 

packages/aws-cdk/lib/commands/migrate.ts

@@ -0,0 +1,71 @@
+import * as fs from 'fs';
+import * as path from 'path';
+import { initializeProject, availableInitTemplates } from '../../lib/init';
+import { warning } from '../logging';
+
+// replace this string with the path to your own noctilucent pkg
+import * as nocti from '/Users/bobertzh/work/noctilucent/noctilucent/pkg/noctilucent';
+
+export async function cliMigrate(
+  inputpath: string = process.cwd() + '/../temp.txt',
+  language?: string,
+  generateOnly = false,
+  outputpath = process.cwd(),
+) {
+  const type = 'default'; // "default" is the default type (and maps to 'app')
+  const template = (await availableInitTemplates()).find(t => t.hasName(type!));
+  if (!template) {
+    throw new Error(`couldn't find template for ${type} app type, this should never happen`);
+  }
+
+  if (!language) {
+    language = 'typescript';
+    warning(`No --language was provided, defaulting to --language=${language}`);
+  }
+
+  await initializeProject(template, language, true, generateOnly, outputpath);
+  const template_file = fs.readFileSync(inputpath, 'utf8');
+  const generated_app = nocti.transmute(template_file, language);
+
+  // clear out the init'd bin/lib files to replace with our own
+  delete_files(outputpath + '/lib/');
+
+  // we hardcode everything to be called noctstack still so this works for now. 
+  // Will change this to be much smarter once we can change stack name in noct
+  const bin_app = `#!/usr/bin/env node
+  import 'source-map-support/register';
+  import * as cdk from 'aws-cdk-lib';
+  import { NoctStack } from '../lib/generated_stack';
+
+  const app = new cdk.App();
+  new NoctStack(app, 'NoctStack', {
+    /* If you don't specify 'env', this stack will be environment-agnostic.
+     * Account/Region-dependent features and context lookups will not work,
+     * but a single synthesized template can be deployed anywhere. */
+
+    /* Uncomment the next line to specialize this stack for the AWS Account
+     * and Region that are implied by the current CLI configuration. */
+    // env: { account: process.env.CDK_DEFAULT_ACCOUNT, region: process.env.CDK_DEFAULT_REGION },
+
+    /* Uncomment the next line if you know exactly what Account and Region you
+     * want to deploy the stack to. */
+    // env: { account: '123456789012', region: 'us-east-1' },
+
+    /* For more information, see https://docs.aws.amazon.com/cdk/latest/guide/environments.html */
+  });`;
+  const myname = path.basename(outputpath);
+  warning(`path name = ${myname}`)
+  fs.writeFileSync(outputpath + '/lib/' + 'generated_stack.ts', generated_app);
+  fs.writeFileSync(outputpath + '/bin/' + `${myname}.ts`, bin_app);
+}
+
+function delete_files(filepath: string) {
+  fs.readdir(filepath, (err, files) => {
+    if (err) throw err;
+    for (const file of files) {
+      fs.unlink(filepath + file, (err) => {
+        if (err) throw err;
+      });
+    }
+  });
+}

packages/aws-cdk/lib/init.ts

@@ -247,7 +247,7 @@ export async function printAvailableTemplates(language?: string) {
   }
 }
 
-async function initializeProject(template: InitTemplate, language: string, canUseNetwork: boolean, generateOnly: boolean, workDir: string) {
+export async function initializeProject(template: InitTemplate, language: string, canUseNetwork: boolean, generateOnly: boolean, workDir: string) {
   await assertIsEmptyDirectory(workDir);
   print(`Applying project template ${chalk.green(template.name)} for ${chalk.blue(language)}`);
   await template.install(language, workDir);