fix(aws-cloudfront): distribution comment length not validated (aws#1…

…4020) (aws#14094)

fixes aws#14020

----

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

packages/@aws-cdk/aws-cloudfront/lib/distribution.ts

@@ -279,6 +279,12 @@ export class Distribution extends Resource implements IDistribution {
     this.certificate = props.certificate;
     this.errorResponses = props.errorResponses ?? [];
 
+    // Comments have an undocumented limit of 128 characters
+    const trimmedComment =
+      props.comment && props.comment.length > 128
+        ? `${props.comment.substr(0, 128 - 3)}...`
+        : props.comment;
+
     const distribution = new CfnDistribution(this, 'Resource', {
       distributionConfig: {
         enabled: props.enabled ?? true,
@@ -287,7 +293,7 @@ export class Distribution extends Resource implements IDistribution {
         defaultCacheBehavior: this.defaultBehavior._renderBehavior(),
         aliases: props.domainNames,
         cacheBehaviors: Lazy.any({ produce: () => this.renderCacheBehaviors() }),
-        comment: props.comment,
+        comment: trimmedComment,
         customErrorResponses: this.renderErrorResponses(),
         defaultRootObject: props.defaultRootObject,
         httpVersion: props.httpVersion ?? HttpVersion.HTTP2,

packages/@aws-cdk/aws-cloudfront/lib/web-distribution.ts

@@ -769,8 +769,14 @@ export class CloudFrontWebDistribution extends cdk.Resource implements IDistribu
   constructor(scope: Construct, id: string, props: CloudFrontWebDistributionProps) {
     super(scope, id);
 
+    // Comments have an undocumented limit of 128 characters
+    const trimmedComment =
+    props.comment && props.comment.length > 128
+      ? `${props.comment.substr(0, 128 - 3)}...`
+      : props.comment;
+
     let distributionConfig: CfnDistribution.DistributionConfigProperty = {
-      comment: props.comment,
+      comment: trimmedComment,
       enabled: true,
       defaultRootObject: props.defaultRootObject ?? 'index.html',
       httpVersion: props.httpVersion || HttpVersion.HTTP2,

packages/@aws-cdk/aws-cloudfront/test/distribution.test.ts

@@ -107,6 +107,40 @@ test('exhaustive example of props renders correctly', () => {
   });
 });
 
+test('ensure comment prop is not greater than max lenght', () => {
+  const origin = defaultOrigin();
+  new Distribution(stack, 'MyDist', {
+    defaultBehavior: { origin },
+    comment: `Adding a comment longer than 128 characters should be trimmed and added the 
+ellipsis so a user would know there was more to read and everything beyond this point should not show up`,
+  });
+
+  expect(stack).toHaveResource('AWS::CloudFront::Distribution', {
+    DistributionConfig: {
+      DefaultCacheBehavior: {
+        CachePolicyId: '658327ea-f89d-4fab-a63d-7e88639e58f6',
+        Compress: true,
+        TargetOriginId: 'StackMyDistOrigin1D6D5E535',
+        ViewerProtocolPolicy: 'allow-all',
+      },
+      Comment: `Adding a comment longer than 128 characters should be trimmed and added the 
+ellipsis so a user would know there was more to ...`,
+      Enabled: true,
+      HttpVersion: 'http2',
+      IPV6Enabled: true,
+      Origins: [
+        {
+          DomainName: 'www.example.com',
+          Id: 'StackMyDistOrigin1D6D5E535',
+          CustomOriginConfig: {
+            OriginProtocolPolicy: 'https-only',
+          },
+        },
+      ],
+    },
+  });
+});
+
 describe('multiple behaviors', () => {
 
   test('a second behavior can\'t be specified with the catch-all path pattern', () => {

packages/@aws-cdk/aws-cloudfront/test/web-distribution.test.ts

@@ -198,6 +198,78 @@ nodeunitShim({
     test.done();
   },
 
+  'ensure long comments will not break the distribution'(test: Test) {
+    const stack = new cdk.Stack();
+    const sourceBucket = new s3.Bucket(stack, 'Bucket');
+
+    new CloudFrontWebDistribution(stack, 'AnAmazingWebsiteProbably', {
+      comment: `Adding a comment longer than 128 characters should be trimmed and 
+added the ellipsis so a user would know there was more to read and everything beyond this point should not show up`,
+      originConfigs: [
+        {
+          s3OriginSource: {
+            s3BucketSource: sourceBucket,
+          },
+          behaviors: [
+            {
+              isDefaultBehavior: true,
+            },
+          ],
+        },
+      ],
+    });
+
+    expect(stack).toMatch({
+      Resources: {
+        Bucket83908E77: {
+          Type: 'AWS::S3::Bucket',
+          DeletionPolicy: 'Retain',
+          UpdateReplacePolicy: 'Retain',
+        },
+        AnAmazingWebsiteProbablyCFDistribution47E3983B: {
+          Type: 'AWS::CloudFront::Distribution',
+          Properties: {
+            DistributionConfig: {
+              DefaultRootObject: 'index.html',
+              Origins: [
+                {
+                  ConnectionAttempts: 3,
+                  ConnectionTimeout: 10,
+                  DomainName: {
+                    'Fn::GetAtt': ['Bucket83908E77', 'RegionalDomainName'],
+                  },
+                  Id: 'origin1',
+                  S3OriginConfig: {},
+                },
+              ],
+              ViewerCertificate: {
+                CloudFrontDefaultCertificate: true,
+              },
+              PriceClass: 'PriceClass_100',
+              DefaultCacheBehavior: {
+                AllowedMethods: ['GET', 'HEAD'],
+                CachedMethods: ['GET', 'HEAD'],
+                TargetOriginId: 'origin1',
+                ViewerProtocolPolicy: 'redirect-to-https',
+                ForwardedValues: {
+                  QueryString: false,
+                  Cookies: { Forward: 'none' },
+                },
+                Compress: true,
+              },
+              Comment: `Adding a comment longer than 128 characters should be trimmed and 
+added the ellipsis so a user would know there was more to ...`,
+              Enabled: true,
+              IPV6Enabled: true,
+              HttpVersion: 'http2',
+            },
+          },
+        },
+      },
+    });
+    test.done();
+  },
+
   'distribution with bucket and OAI'(test: Test) {
     const stack = new cdk.Stack();
     const s3BucketSource = new s3.Bucket(stack, 'Bucket');