feat(amplify): Add support for custom headers in the App

package.json

@@ -81,6 +81,8 @@
       "@aws-cdk/assertions-alpha/string-width/**",
       "@aws-cdk/assertions-alpha/table",
       "@aws-cdk/assertions-alpha/table/**",
+      "@aws-cdk/aws-amplify-alpha/yaml",
+      "@aws-cdk/aws-amplify-alpha/yaml/**",
       "@aws-cdk/assertions/colors",
       "@aws-cdk/assertions/colors/**",
       "@aws-cdk/assertions/diff",
@@ -91,6 +93,8 @@
       "@aws-cdk/assertions/string-width/**",
       "@aws-cdk/assertions/table",
       "@aws-cdk/assertions/table/**",
+      "@aws-cdk/aws-amplify/yaml",
+      "@aws-cdk/aws-amplify/yaml/**",
       "@aws-cdk/aws-codebuild/yaml",
       "@aws-cdk/aws-codebuild/yaml/**",
       "@aws-cdk/aws-codepipeline-actions/case",

packages/@aws-cdk/aws-amplify/NOTICE

@@ -1,2 +1,23 @@
 AWS Cloud Development Kit (AWS CDK)
 Copyright 2018-2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+
+-------------------------------------------------------------------------------
+
+The AWS CDK includes the following third-party software/licensing:
+
+** yaml - https://www.npmjs.com/package/yaml
+Copyright 2018 Eemeli Aro <eemeli@gmail.com>
+
+Permission to use, copy, modify, and/or distribute this software for any purpose
+with or without fee is hereby granted, provided that the above copyright notice
+and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
+THIS SOFTWARE.
+
+----------------

packages/@aws-cdk/aws-amplify/README.md

@@ -178,3 +178,32 @@ const amplifyApp = new amplify.App(this, 'MyApp', {
   autoBranchDeletion: true, // Automatically disconnect a branch when you delete a branch from your repository
 });
 ```
+
+## Adding custom response headers
+
+Use the `customResponseHeaders` prop to configure custom response headers for an Amplify app:
+
+```ts
+const amplifyApp = new amplify.App(stack, 'App', {
+  sourceCodeProvider: new amplify.GitHubSourceCodeProvider({
+    owner: '<user>',
+    repository: '<repo>',
+    oauthToken: cdk.SecretValue.secretsManager('my-github-token')
+  }),
+  customResponseHeaders: [
+    {
+      pattern: '*.json',
+      headers: {
+        'custom-header-name-1': 'custom-header-value-1',
+        'custom-header-name-2': 'custom-header-value-2',
+      },
+    },
+    {
+      pattern: '/path/*',
+      headers: {
+        'custom-header-name-1': 'custom-header-value-2',
+      },
+    },
+  ],
+});
+```

packages/@aws-cdk/aws-amplify/lib/app.ts

@@ -2,6 +2,7 @@ import * as codebuild from '@aws-cdk/aws-codebuild';
 import * as iam from '@aws-cdk/aws-iam';
 import { IResource, Lazy, Resource, SecretValue } from '@aws-cdk/core';
 import { Construct } from 'constructs';
+import * as YAML from 'yaml';
 import { CfnApp } from './amplify.generated';
 import { BasicAuth } from './basic-auth';
 import { Branch, BranchOptions } from './branch';
@@ -118,6 +119,16 @@ export interface AppProps {
    */
   readonly buildSpec?: codebuild.BuildSpec;
 
+
+  /**
+   * The custom HTTP response headers for an Amplify app.
+   *
+   * @see https://docs.aws.amazon.com/amplify/latest/userguide/custom-headers.html
+   *
+   * @default - no custom response headers
+   */
+  readonly customResponseHeaders?: CustomResponseHeader[];
+
   /**
    * Custom rewrite/redirect rules for the application
    *
@@ -238,6 +249,7 @@ export class App extends Resource implements IApp, iam.IGrantable {
       name: props.appName || this.node.id,
       oauthToken: sourceCodeProviderOptions?.oauthToken?.toString(),
       repository: sourceCodeProviderOptions?.repository,
+      customHeaders: props.customResponseHeaders ? renderCustomResponseHeaders(props.customResponseHeaders) : undefined,
     });
 
     this.appId = app.attrAppId;
@@ -486,3 +498,28 @@ export class CustomRule {
     this.condition = options.condition;
   }
 }
+
+/**
+ * Custom response header of an Amplify App.
+ */
+export interface CustomResponseHeader {
+  /**
+   * These custom headers will be applied to all URL file paths that match this pattern.
+   */
+  readonly pattern: string;
+
+  /**
+   * The map of custom headers to be applied.
+   */
+  readonly headers: { [key: string]: string };
+}
+
+function renderCustomResponseHeaders(customHeaders: CustomResponseHeader[]): string {
+  const modifiedHeaders = customHeaders.map(customHeader => ({
+    ...customHeader,
+    headers: Object.entries(customHeader.headers).map(([key, value]) => ({ key, value })),
+  }));
+
+  const customHeadersObject = { customHeaders: modifiedHeaders };
+  return YAML.stringify(customHeadersObject);
+}

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

@@ -79,7 +79,8 @@
     "@aws-cdk/cdk-integ-tools": "0.0.0",
     "@aws-cdk/cfn2ts": "0.0.0",
     "@aws-cdk/pkglint": "0.0.0",
-    "@types/jest": "^26.0.24"
+    "@types/jest": "^26.0.24",
+    "@types/yaml": "1.9.6"
   },
   "dependencies": {
     "@aws-cdk/aws-codebuild": "0.0.0",
@@ -88,8 +89,12 @@
     "@aws-cdk/aws-kms": "0.0.0",
     "@aws-cdk/aws-secretsmanager": "0.0.0",
     "@aws-cdk/core": "0.0.0",
-    "constructs": "^3.3.69"
+    "constructs": "^3.3.69",
+    "yaml": "1.10.2"
   },
+  "bundledDependencies": [
+    "yaml"
+  ],
   "peerDependencies": {
     "@aws-cdk/aws-codebuild": "0.0.0",
     "@aws-cdk/aws-codecommit": "0.0.0",

packages/@aws-cdk/aws-amplify/test/app.test.ts

@@ -394,3 +394,34 @@ test('with auto branch deletion', () => {
     EnableBranchAutoDeletion: true,
   });
 });
+
+test('with custom headers', () => {
+  // WHEN
+  new amplify.App(stack, 'App', {
+    sourceCodeProvider: new amplify.GitHubSourceCodeProvider({
+      owner: 'aws',
+      repository: 'aws-cdk',
+      oauthToken: SecretValue.plainText('secret'),
+    }),
+    customResponseHeaders: [
+      {
+        pattern: '*.json',
+        headers: {
+          'custom-header-name-1': 'custom-header-value-1',
+          'custom-header-name-2': 'custom-header-value-2',
+        },
+      },
+      {
+        pattern: '/path/*',
+        headers: {
+          'custom-header-name-1': 'custom-header-value-2',
+        },
+      },
+    ],
+  });
+
+  // THEN
+  Template.fromStack(stack).hasResourceProperties('AWS::Amplify::App', {
+    CustomHeaders: 'customHeaders:\n  - pattern: "*.json"\n    headers:\n      - key: custom-header-name-1\n        value: custom-header-value-1\n      - key: custom-header-name-2\n        value: custom-header-value-2\n  - pattern: /path/*\n    headers:\n      - key: custom-header-name-1\n        value: custom-header-value-2\n',
+  });
+});

packages/@aws-cdk/aws-amplify/test/integ.app.expected.json

@@ -54,6 +54,7 @@
           },
           "Username": "aws"
         },
+        "CustomHeaders": "customHeaders:\n  - pattern: \"*.json\"\n    headers:\n      - key: custom-header-name-1\n        value: custom-header-value-1\n      - key: custom-header-name-2\n        value: custom-header-value-2\n  - pattern: /path/*\n    headers:\n      - key: custom-header-name-1\n        value: custom-header-value-2\n",
         "CustomRules": [
           {
             "Source": "/source",

packages/@aws-cdk/aws-amplify/test/integ.app.ts

@@ -9,6 +9,21 @@ class TestStack extends Stack {
     const amplifyApp = new amplify.App(this, 'App', {
       basicAuth: amplify.BasicAuth.fromGeneratedPassword('aws'),
       autoBranchCreation: {},
+      customResponseHeaders: [
+        {
+          pattern: '*.json',
+          headers: {
+            'custom-header-name-1': 'custom-header-value-1',
+            'custom-header-name-2': 'custom-header-value-2',
+          },
+        },
+        {
+          pattern: '/path/*',
+          headers: {
+            'custom-header-name-1': 'custom-header-value-2',
+          },
+        },
+      ],
     });
 
     amplifyApp.addCustomRule({