feat(docdb): add the ability to exclude characters when generating passwords (aws#17262)

Add property `excludeCharaters` to provide the ability to exclude characters when generating passwords in DocumentDB.

Requested in aws#15732.

----

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

Author: jumic

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

@@ -21,6 +21,7 @@ your instances will be launched privately or publicly:
 const cluster = new DatabaseCluster(this, 'Database', {
     masterUser: {
         username: 'myuser' // NOTE: 'admin' is reserved by DocumentDB
+        excludeCharacters: '\"@/:', // optional, defaults to the set "\"@/"
     },
     instanceType: ec2.InstanceType.of(ec2.InstanceClass.R5, ec2.InstanceSize.LARGE),
     vpcSubnets: {

packages/@aws-cdk/aws-docdb/lib/cluster.ts

@@ -352,6 +352,7 @@ export class DatabaseCluster extends DatabaseClusterBase {
       secret = new DatabaseSecret(this, 'Secret', {
         username: props.masterUser.username,
         encryptionKey: props.masterUser.kmsKey,
+        excludeCharacters: props.masterUser.excludeCharacters,
       });
     }
 

packages/@aws-cdk/aws-docdb/lib/database-secret.ts

@@ -32,6 +32,13 @@ export interface DatabaseSecretProps {
    * @default - no master secret information will be included
    */
   readonly masterSecret?: ISecret;
+
+  /**
+   * Characters to not include in the generated password.
+   *
+   * @default "\"@/"
+   */
+  readonly excludeCharacters?: string;
 }
 
 /**
@@ -61,7 +68,7 @@ export class DatabaseSecret extends Secret {
           masterarn: props.masterSecret?.secretArn,
         }),
         generateStringKey: 'password',
-        excludeCharacters: '"@/',
+        excludeCharacters: props.excludeCharacters ?? '"@/',
       },
     });
   }

packages/@aws-cdk/aws-docdb/lib/props.ts

@@ -53,6 +53,13 @@ export interface Login {
    * @default default master key
    */
   readonly kmsKey?: kms.IKey;
+
+  /**
+   * Specifies characters to not include in generated passwords.
+   *
+   * @default "\"@/"
+   */
+  readonly excludeCharacters?: string;
 }
 
 /**

packages/@aws-cdk/aws-docdb/test/cluster.test.ts

@@ -1,4 +1,4 @@
-import { expect as expectCDK, haveResource, ResourcePart, arrayWith } from '@aws-cdk/assert-internal';
+import { expect as expectCDK, haveResource, ResourcePart, arrayWith, haveResourceLike, objectLike } from '@aws-cdk/assert-internal';
 import * as ec2 from '@aws-cdk/aws-ec2';
 import * as kms from '@aws-cdk/aws-kms';
 import * as cdk from '@aws-cdk/core';
@@ -293,6 +293,29 @@ describe('DatabaseCluster', () => {
     }));
   });
 
+  test('creates a secret with excludeCharacters', () => {
+    // GIVEN
+    const stack = testStack();
+    const vpc = new ec2.Vpc(stack, 'VPC');
+
+    // WHEN
+    new DatabaseCluster(stack, 'Database', {
+      masterUser: {
+        username: 'admin',
+        excludeCharacters: '"@/()[]',
+      },
+      instanceType: ec2.InstanceType.of(ec2.InstanceClass.BURSTABLE2, ec2.InstanceSize.SMALL),
+      vpc,
+    });
+
+    // THEN
+    expectCDK(stack).to(haveResourceLike('AWS::SecretsManager::Secret', {
+      GenerateSecretString: objectLike({
+        ExcludeCharacters: '\"@/()[]',
+      }),
+    }));
+  });
+
   test('create an encrypted cluster with custom KMS key', () => {
     // GIVEN
     const stack = testStack();