feat(cloudfront): add convenience grant methods to IDistribution

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

@@ -590,6 +590,18 @@ const distribution = cloudfront.Distribution.fromDistributionAttributes(this, 'I
 });
 ```
 
+### Permissions
+
+Use the `grant()` method to allow actions on the distribution.
+`grantCreateInvalidation()` is a shorthand to allow `CreateInvalidation`.
+
+```ts
+declare const distribution: cloudfront.Distribution;
+declare const lambdaFn: lambda.Function;
+distribution.grant(lambdaFn, 'cloudfront:ListInvalidations', 'cloudfront:GetInvalidation');
+distribution.grantCreateInvalidation(lambdaFn);
+```
+
 ## Migrating from the original CloudFrontWebDistribution to the newer Distribution construct
 
 It's possible to migrate a distribution from the original to the modern API.

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

@@ -1,4 +1,5 @@
 import * as acm from '@aws-cdk/aws-certificatemanager';
+import * as iam from '@aws-cdk/aws-iam';
 import * as lambda from '@aws-cdk/aws-lambda';
 import * as s3 from '@aws-cdk/aws-s3';
 import { ArnFormat, IResource, Lazy, Resource, Stack, Token, Duration, Names, FeatureFlags } from '@aws-cdk/core';
@@ -12,6 +13,7 @@ import { IKeyGroup } from './key-group';
 import { IOrigin, OriginBindConfig, OriginBindOptions } from './origin';
 import { IOriginRequestPolicy } from './origin-request-policy';
 import { CacheBehavior } from './private/cache-behavior';
+import { formatDistributionArn } from './private/utils';
 import { IResponseHeadersPolicy } from './response-headers-policy';
 
 /**
@@ -39,6 +41,22 @@ export interface IDistribution extends IResource {
    * @attribute
    */
   readonly distributionId: string;
+
+  /**
+   * Adds an IAM policy statement associated with this distribution to an IAM
+   * principal's policy.
+   *
+   * @param identity The principal
+   * @param actions The set of actions to allow (i.e. "cloudfront:ListInvalidations")
+   */
+  grant(identity: iam.IGrantable, ...actions: string[]): iam.Grant;
+
+  /**
+   * Grant to create invalidations for this bucket to an IAM principal (Role/Group/User).
+   *
+   * @param identity The principal
+   */
+  grantCreateInvalidation(identity: iam.IGrantable): iam.Grant;
 }
 
 /**
@@ -257,6 +275,13 @@ export class Distribution extends Resource implements IDistribution {
         this.distributionDomainName = attrs.domainName;
         this.distributionId = attrs.distributionId;
       }
+
+      public grant(grantee: iam.IGrantable, ...actions: string[]): iam.Grant {
+        return iam.Grant.addToPrincipal({ grantee, actions, resourceArns: [formatDistributionArn(this)] });
+      }
+      public grantCreateInvalidation(grantee: iam.IGrantable): iam.Grant {
+        return this.grant(grantee, 'cloudfront:CreateInvalidation');
+      }
     }();
   }
 
@@ -345,6 +370,26 @@ export class Distribution extends Resource implements IDistribution {
     this.additionalBehaviors.push(new CacheBehavior(originId, { pathPattern, ...behaviorOptions }));
   }
 
+  /**
+   * Adds an IAM policy statement associated with this distribution to an IAM
+   * principal's policy.
+   *
+   * @param identity The principal
+   * @param actions The set of actions to allow (i.e. "cloudfront:ListInvalidations")
+   */
+  public grant(identity: iam.IGrantable, ...actions: string[]): iam.Grant {
+    return iam.Grant.addToPrincipal({ grantee: identity, actions, resourceArns: [formatDistributionArn(this)] });
+  }
+
+  /**
+   * Grant to create invalidations for this bucket to an IAM principal (Role/Group/User).
+   *
+   * @param identity The principal
+   */
+  public grantCreateInvalidation(identity: iam.IGrantable): iam.Grant {
+    return this.grant(identity, 'cloudfront:CreateInvalidation');
+  }
+
   private addOrigin(origin: IOrigin, isFailoverOrigin: boolean = false): string {
     const ORIGIN_ID_MAX_LENGTH = 128;
 

packages/@aws-cdk/aws-cloudfront/lib/private/utils.ts

@@ -0,0 +1,14 @@
+import { Stack } from '@aws-cdk/core';
+import { IDistribution } from '..';
+
+/**
+ * Format distribution ARN from stack and distribution ID.
+ */
+export function formatDistributionArn(dist: IDistribution) {
+  return Stack.of(dist).formatArn({
+    service: 'cloudfront',
+    region: '',
+    resource: 'distribution',
+    resourceName: dist.distributionId,
+  });
+}

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

@@ -10,6 +10,7 @@ import { FunctionAssociation } from './function';
 import { GeoRestriction } from './geo-restriction';
 import { IKeyGroup } from './key-group';
 import { IOriginAccessIdentity } from './origin-access-identity';
+import { formatDistributionArn } from './private/utils';
 
 /**
  * HTTP status code to failover to second origin
@@ -758,6 +759,13 @@ export class CloudFrontWebDistribution extends cdk.Resource implements IDistribu
         this.distributionDomainName = attrs.domainName;
         this.distributionId = attrs.distributionId;
       }
+
+      public grant(grantee: iam.IGrantable, ...actions: string[]): iam.Grant {
+        return iam.Grant.addToPrincipal({ grantee, actions, resourceArns: [formatDistributionArn(this)] });
+      }
+      public grantCreateInvalidation(identity: iam.IGrantable): iam.Grant {
+        return this.grant(identity, 'cloudfront:CreateInvalidation');
+      }
     }();
   }
 
@@ -983,6 +991,26 @@ export class CloudFrontWebDistribution extends cdk.Resource implements IDistribu
     this.distributionId = distribution.ref;
   }
 
+  /**
+   * Adds an IAM policy statement associated with this distribution to an IAM
+   * principal's policy.
+   *
+   * @param identity The principal
+   * @param actions The set of actions to allow (i.e. "cloudfront:ListInvalidations")
+   */
+  public grant(identity: iam.IGrantable, ...actions: string[]): iam.Grant {
+    return iam.Grant.addToPrincipal({ grantee: identity, actions, resourceArns: [formatDistributionArn(this)] });
+  }
+
+  /**
+   * Grant to create invalidations for this bucket to an IAM principal (Role/Group/User).
+   *
+   * @param identity The principal
+   */
+  grantCreateInvalidation(identity: iam.IGrantable): iam.Grant {
+    return this.grant(identity, 'cloudfront:CreateInvalidation');
+  }
+
   private toBehavior(input: BehaviorWithOrigin, protoPolicy?: ViewerProtocolPolicy) {
     let toReturn = {
       allowedMethods: this.METHOD_LOOKUP_MAP[input.allowedMethods || CloudFrontAllowedMethods.GET_HEAD],

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

@@ -1,5 +1,6 @@
 import { Match, Template } from '@aws-cdk/assertions';
 import * as acm from '@aws-cdk/aws-certificatemanager';
+import * as iam from '@aws-cdk/aws-iam';
 import * as lambda from '@aws-cdk/aws-lambda';
 import * as s3 from '@aws-cdk/aws-s3';
 import { App, Duration, Stack } from '@aws-cdk/core';
@@ -1025,3 +1026,62 @@ describe('supported HTTP versions', () => {
     });
   });
 });
+
+test('grants custom actions', () => {
+  const distribution = new Distribution(stack, 'Distribution', {
+    defaultBehavior: { origin: defaultOrigin() },
+  });
+  const role = new iam.Role(stack, 'Role', {
+    assumedBy: new iam.AccountRootPrincipal(),
+  });
+  distribution.grant(role, 'cloudfront:ListInvalidations', 'cloudfront:GetInvalidation');
+
+  Template.fromStack(stack).hasResourceProperties('AWS::IAM::Policy', {
+    PolicyDocument: {
+      Statement: [
+        {
+          Action: [
+            'cloudfront:ListInvalidations',
+            'cloudfront:GetInvalidation',
+          ],
+          Resource: {
+            'Fn::Join': [
+              '', [
+                'arn:', { Ref: 'AWS::Partition' }, ':cloudfront::1234:distribution/',
+                { Ref: 'Distribution830FAC52' },
+              ],
+            ],
+          },
+        },
+      ],
+    },
+  });
+});
+
+test('grants createInvalidation', () => {
+  const distribution = new Distribution(stack, 'Distribution', {
+    defaultBehavior: { origin: defaultOrigin() },
+  });
+  const role = new iam.Role(stack, 'Role', {
+    assumedBy: new iam.AccountRootPrincipal(),
+  });
+  distribution.grantCreateInvalidation(role);
+
+  Template.fromStack(stack).hasResourceProperties('AWS::IAM::Policy', {
+    PolicyDocument: {
+      Statement: [
+        {
+          Action: 'cloudfront:CreateInvalidation',
+          Resource: {
+            'Fn::Join': [
+              '', [
+                'arn:', { Ref: 'AWS::Partition' }, ':cloudfront::1234:distribution/',
+                { Ref: 'Distribution830FAC52' },
+              ],
+            ],
+          },
+        },
+      ],
+    },
+  });
+});

packages/@aws-cdk/aws-cloudfront/test/integ.distribution-basic.js.snapshot/cdk.out

@@ -1 +1 @@
-{"version":"20.0.0"}
+{"version":"21.0.0"}

packages/@aws-cdk/aws-cloudfront/test/integ.distribution-basic.js.snapshot/integ-distribution-basic.assets.json

@@ -1,15 +1,15 @@
 {
-  "version": "20.0.0",
+  "version": "21.0.0",
   "files": {
-    "e56a9eb81eb88d748b8062f87488a5f2d9ec1137d330b9d5e0eb33f3ea9de5c7": {
+    "36c6ded30c4c42464c2753c997c004bf740b9311a744c363fda5f951929a9504": {
       "source": {
         "path": "integ-distribution-basic.template.json",
         "packaging": "file"
       },
       "destinations": {
         "current_account-current_region": {
           "bucketName": "cdk-hnb659fds-assets-${AWS::AccountId}-${AWS::Region}",
-          "objectKey": "e56a9eb81eb88d748b8062f87488a5f2d9ec1137d330b9d5e0eb33f3ea9de5c7.json",
+          "objectKey": "36c6ded30c4c42464c2753c997c004bf740b9311a744c363fda5f951929a9504.json",
           "assumeRoleArn": "arn:${AWS::Partition}:iam::${AWS::AccountId}:role/cdk-hnb659fds-file-publishing-role-${AWS::AccountId}-${AWS::Region}"
         }
       }