chore(migrate): add migrate information to AWS::CDK::Metadata (#28958)

This change adds a new context key to the `cdk.json` file when an app is generated by the `cdk migrate` cli command. If the context key `"cdk-migrate"` is `true`, then that information is added to the end of the analytics string in the AWS::CDK::Metadata resource. 


----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/aws-cdk-lib/core/lib/private/metadata-resource.ts

@@ -16,7 +16,6 @@ import { Token } from '../token';
 export class MetadataResource extends Construct {
   constructor(scope: Stack, id: string) {
     super(scope, id);
-
     const metadataServiceExists = Token.isUnresolved(scope.region) || RegionInfo.get(scope.region).cdkMetadataResourceAvailable;
     if (metadataServiceExists) {
       const resource = new CfnResource(this, 'Default', {
@@ -51,22 +50,30 @@ function makeCdkMetadataAvailableCondition() {
 class Trie extends Map<string, Trie> { }
 
 /**
- * Formats a list of construct fully-qualified names (FQNs) and versions into a (possibly compressed) prefix-encoded string.
+ * Formats the analytics string which has 3 or 4 sections separated by colons (:)
+ *
+ * version:encoding:constructinfo OR version:encoding:constructinfo:appinfo
  *
- * The list of ConstructInfos is logically formatted into:
- * ${version}!${fqn} (e.g., "1.90.0!aws-cdk-lib.Stack")
- * and then all of the construct-versions are grouped with common prefixes together, grouping common parts in '{}' and separating items with ','.
+ * The constructinfo section is a list of construct fully-qualified names (FQNs)
+ * and versions into a (possibly compressed) prefix-encoded string.
+ *
+ * The list of ConstructInfos is logically formatted into: ${version}!${fqn}
+ * (e.g., "1.90.0!aws-cdk-lib.Stack") and then all of the construct-versions are
+ * grouped with common prefixes together, grouping common parts in '{}' and
+ * separating items with ','.
  *
  * Example:
  * [1.90.0!aws-cdk-lib.Stack, 1.90.0!aws-cdk-lib.Construct, 1.90.0!aws-cdk-lib.service.Resource, 0.42.1!aws-cdk-lib-experiments.NewStuff]
  * Becomes:
  * 1.90.0!aws-cdk-lib.{Stack,Construct,service.Resource},0.42.1!aws-cdk-lib-experiments.NewStuff
  *
- * The whole thing is then either included directly as plaintext as:
- * v2:plaintext:{prefixEncodedList}
- * Or is compressed and base64-encoded, and then formatted as:
+ * The whole thing is then compressed and base64-encoded, and then formatted as:
  * v2:deflate64:{prefixEncodedListCompressedAndEncoded}
  *
+ * The appinfo section is optional, and currently only added if the app was generated using `cdk migrate`
+ * It is also compressed and base64-encoded. In this case, the string will be formatted as:
+ * v2:deflate64:{prefixEncodedListCompressedAndEncoded}:{'cdk-migrate'CompressedAndEncoded}
+ *
  * Exported/visible for ease of testing.
  */
 export function formatAnalytics(infos: ConstructInfo[]) {
@@ -81,7 +88,15 @@ export function formatAnalytics(infos: ConstructInfo[]) {
   setGzipOperatingSystemToUnknown(compressedConstructsBuffer);
 
   const compressedConstructs = compressedConstructsBuffer.toString('base64');
-  return `v2:deflate64:${compressedConstructs}`;
+  const analyticsString = `v2:deflate64:${compressedConstructs}`;
+
+  if (process.env.CDK_CONTEXT_JSON && JSON.parse(process.env.CDK_CONTEXT_JSON)['cdk-migrate']) {
+    const compressedAppInfoBuffer = zlib.gzipSync(Buffer.from('cdk-migrate'));
+    const compressedAppInfo = compressedAppInfoBuffer.toString('base64');
+    analyticsString.concat(':', compressedAppInfo);
+  }
+
+  return analyticsString;
 }
 
 /**

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

@@ -38,6 +38,7 @@ export async function generateCdkApp(stackName: string, stack: string, language:
       generateOnly,
       workDir: resolvedOutputPath,
       stackName,
+      migrate: true,
     });
 
     let stackFileName: string;

packages/aws-cdk/lib/init.ts

@@ -21,6 +21,7 @@ export interface CliInitOptions {
   readonly generateOnly?: boolean;
   readonly workDir?: string;
   readonly stackName?: string;
+  readonly migrate?: boolean;
 }
 
 /**
@@ -51,7 +52,7 @@ export async function cliInit(options: CliInitOptions) {
     throw new Error('No language was selected');
   }
 
-  await initializeProject(template, options.language, canUseNetwork, generateOnly, workDir, options.stackName);
+  await initializeProject(template, options.language, canUseNetwork, generateOnly, workDir, options.stackName, options.migrate);
 }
 
 /**
@@ -203,6 +204,21 @@ export class InitTemplate {
 
     await fs.writeJson(cdkJson, config, { spaces: 2 });
   }
+
+  public async addMigrateContext(projectDir: string) {
+    const cdkJson = path.join(projectDir, 'cdk.json');
+    if (!await fs.pathExists(cdkJson)) {
+      return;
+    }
+
+    const config = await fs.readJson(cdkJson);
+    config.context = {
+      ...config.context,
+      'cdk-migrate': true,
+    };
+
+    await fs.writeJson(cdkJson, config, { spaces: 2 });
+  }
 }
 
 interface ProjectInfo {
@@ -271,10 +287,14 @@ async function initializeProject(
   generateOnly: boolean,
   workDir: string,
   stackName?: string,
+  migrate?: boolean,
 ) {
   await assertIsEmptyDirectory(workDir);
   print(`Applying project template ${chalk.green(template.name)} for ${chalk.blue(language)}`);
   await template.install(language, workDir, stackName);
+  if (migrate) {
+    await template.addMigrateContext(workDir);
+  }
   if (await fs.pathExists('README.md')) {
     print(chalk.green(await fs.readFile('README.md', { encoding: 'utf-8' })));
   }

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

@@ -152,6 +152,18 @@ describe('Migrate Function Tests', () => {
     expect(replacedStack).toEqual(fs.readFileSync(path.join(...stackPath, 's3-stack.ts'), 'utf8'));
   });
 
+  cliTest('generateCdkApp adds cdk-migrate key in context', async (workDir) => {
+    const stack = generateStack(validTemplate, 'GoodTypeScript', 'typescript');
+    await generateCdkApp('GoodTypeScript', stack, 'typescript', workDir);
+
+    // cdk.json exist in the correct spot
+    expect(fs.pathExistsSync(path.join(workDir, 'GoodTypeScript', 'cdk.json'))).toBeTruthy();
+
+    // cdk.json has "cdk-migrate" : true in context
+    const cdkJson = fs.readJsonSync(path.join(workDir, 'GoodTypeScript', 'cdk.json'), 'utf8');
+    expect(cdkJson.context['cdk-migrate']).toBeTruthy();
+  });
+
   cliTest('generateCdkApp generates the expected cdk app when called for python', async (workDir) => {
     const stack = generateStack(validTemplate, 'GoodPython', 'python');
     await generateCdkApp('GoodPython', stack, 'python', workDir);