feat(cloudfront): add Lambda associations (#2760)

This enables to associate a lambda to a distribution behaviour. The lambda could be associated with the four available event-types.

Author: KnisterPeter

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

@@ -1,3 +1,4 @@
+import lambda = require('@aws-cdk/aws-lambda');
 import s3 = require('@aws-cdk/aws-s3');
 import cdk = require('@aws-cdk/cdk');
 import { CfnDistribution } from './cloudfront.generated';
@@ -344,6 +345,48 @@ export interface Behavior {
    */
   readonly maxTtlSeconds?: number;
 
+  /**
+   * Declares associated lambda@edge functions for this distribution behaviour.
+   *
+   * @default No lambda function associated
+   */
+  readonly lambdaFunctionAssociations?: LambdaFunctionAssociation[];
+
+}
+
+export interface LambdaFunctionAssociation {
+
+  /**
+   * The lambda event type defines at which event the lambda
+   * is called during the request lifecycle
+   */
+  readonly eventType: LambdaEdgeEventType;
+
+  /**
+   * A version of the lambda to associate
+   */
+  readonly lambdaFunction: lambda.IVersion;
+}
+
+export enum LambdaEdgeEventType {
+  /**
+   * The origin-request specifies the request to the
+   * origin location (e.g. S3)
+   */
+  OriginRequest = "origin-request",
+  /**
+   * The origin-response specifies the response from the
+   * origin location (e.g. S3)
+   */
+  OriginResponse = "origin-response",
+  /**
+   * The viewer-request specifies the incoming request
+   */
+  ViewerRequest = "viewer-request",
+  /**
+   * The viewer-response specifies the outgoing reponse
+   */
+  ViewerResponse = "viewer-response",
 }
 
 export interface ErrorConfiguration {
@@ -691,6 +734,15 @@ export class CloudFrontWebDistribution extends cdk.Construct implements IDistrib
     if (!input.isDefaultBehavior) {
       toReturn = Object.assign(toReturn, { pathPattern: input.pathPattern });
     }
+    if (input.lambdaFunctionAssociations) {
+      toReturn = Object.assign(toReturn, {
+        lambdaFunctionAssociations: input.lambdaFunctionAssociations
+          .map(fna => ({
+            eventType: fna.eventType,
+            lambdaFunctionArn: fna.lambdaFunction && fna.lambdaFunction.versionArn,
+          }))
+      });
+    }
     return toReturn;
   }
 }

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

@@ -74,6 +74,7 @@
     "@aws-cdk/aws-certificatemanager": "^0.34.0",
     "@aws-cdk/aws-iam": "^0.34.0",
     "@aws-cdk/aws-kms": "^0.34.0",
+    "@aws-cdk/aws-lambda": "^0.34.0",
     "@aws-cdk/aws-s3": "^0.34.0",
     "@aws-cdk/cdk": "^0.34.0"
   },
@@ -82,11 +83,12 @@
     "@aws-cdk/aws-certificatemanager": "^0.34.0",
     "@aws-cdk/aws-iam": "^0.34.0",
     "@aws-cdk/aws-kms": "^0.34.0",
+    "@aws-cdk/aws-lambda": "^0.34.0",
     "@aws-cdk/aws-s3": "^0.34.0",
     "@aws-cdk/cdk": "^0.34.0"
   },
   "engines": {
     "node": ">= 8.10.0"
   },
   "stability": "experimental"
-}
+}

packages/@aws-cdk/aws-cloudfront/test/integ.cloudfront-lambda-association.expected.json

@@ -0,0 +1,129 @@
+{
+  "Resources": {
+    "Bucket83908E77": {
+      "Type": "AWS::S3::Bucket"
+    },
+    "LambdaServiceRoleA8ED4D3B": {
+      "Type": "AWS::IAM::Role",
+      "Properties": {
+        "AssumeRolePolicyDocument": {
+          "Statement": [
+            {
+              "Action": "sts:AssumeRole",
+              "Effect": "Allow",
+              "Principal": {
+                "Service": {
+                  "Fn::Join": [
+                    "",
+                    [
+                      "lambda.",
+                      {
+                        "Ref": "AWS::URLSuffix"
+                      }
+                    ]
+                  ]
+                }
+              }
+            }
+          ],
+          "Version": "2012-10-17"
+        },
+        "ManagedPolicyArns": [
+          {
+            "Fn::Join": [
+              "",
+              [
+                "arn:",
+                {
+                  "Ref": "AWS::Partition"
+                },
+                ":iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
+              ]
+            ]
+          }
+        ]
+      }
+    },
+    "LambdaD247545B": {
+      "Type": "AWS::Lambda::Function",
+      "Properties": {
+        "Code": {
+          "ZipFile": "foo"
+        },
+        "Handler": "index.handler",
+        "Role": {
+          "Fn::GetAtt": [
+            "LambdaServiceRoleA8ED4D3B",
+            "Arn"
+          ]
+        },
+        "Runtime": "nodejs8.10"
+      },
+      "DependsOn": [
+        "LambdaServiceRoleA8ED4D3B"
+      ]
+    },
+    "LambdaVersionFA49E61E": {
+      "Type": "AWS::Lambda::Version",
+      "Properties": {
+        "FunctionName": {
+          "Ref": "LambdaD247545B"
+        }
+      }
+    },
+    "MyDistributionCFDistributionDE147309": {
+      "Type": "AWS::CloudFront::Distribution",
+      "Properties": {
+        "DistributionConfig": {
+          "CacheBehaviors": [],
+          "DefaultCacheBehavior": {
+            "AllowedMethods": [
+              "GET",
+              "HEAD"
+            ],
+            "CachedMethods": [
+              "GET",
+              "HEAD"
+            ],
+            "ForwardedValues": {
+              "Cookies": {
+                "Forward": "none"
+              },
+              "QueryString": false
+            },
+            "TargetOriginId": "origin1",
+            "ViewerProtocolPolicy": "redirect-to-https",
+            "LambdaFunctionAssociations": [
+              {
+                "EventType": "origin-request",
+                "LambdaFunctionARN": {
+                  "Ref": "LambdaVersionFA49E61E"
+                }
+              }
+            ]
+          },
+          "DefaultRootObject": "index.html",
+          "Enabled": true,
+          "HttpVersion": "http2",
+          "IPV6Enabled": true,
+          "Origins": [
+            {
+              "DomainName": {
+                "Fn::GetAtt": [
+                  "Bucket83908E77",
+                  "RegionalDomainName"
+                ]
+              },
+              "Id": "origin1",
+              "S3OriginConfig": {}
+            }
+          ],
+          "PriceClass": "PriceClass_100",
+          "ViewerCertificate": {
+            "CloudFrontDefaultCertificate": true
+          }
+        }
+      }
+    }
+  }
+}

packages/@aws-cdk/aws-cloudfront/test/integ.cloudfront-lambda-association.ts

@@ -0,0 +1,38 @@
+import lambda = require('@aws-cdk/aws-lambda');
+import s3 = require('@aws-cdk/aws-s3');
+import cdk = require('@aws-cdk/cdk');
+import cloudfront = require('../lib');
+
+const app = new cdk.App();
+
+const stack = new cdk.Stack(app, 'aws-cdk-cloudfront');
+
+const sourceBucket = new s3.Bucket(stack, 'Bucket', {
+  removalPolicy: cdk.RemovalPolicy.Destroy
+});
+
+const lambdaFunction = new lambda.Function(stack, 'Lambda', {
+  code: lambda.Code.inline('foo'),
+  handler: 'index.handler',
+  runtime: lambda.Runtime.NodeJS810
+});
+
+const lambdaVersion = new lambda.Version(stack, 'LambdaVersion', {
+  lambda: lambdaFunction
+});
+
+new cloudfront.CloudFrontWebDistribution(stack, 'MyDistribution', {
+  originConfigs: [
+    {
+      s3OriginSource: {
+        s3BucketSource: sourceBucket
+      },
+      behaviors : [ {isDefaultBehavior: true, lambdaFunctionAssociations: [{
+        eventType: cloudfront.LambdaEdgeEventType.OriginRequest,
+        lambdaFunction: lambdaVersion
+      }]}]
+    }
+  ]
+ });
+
+app.run();

packages/@aws-cdk/aws-lambda/lib/lambda-version.ts

@@ -9,6 +9,12 @@ export interface IVersion extends IResource {
    */
   readonly version: string;
 
+  /**
+   * The ARN of this version.
+   * @attribute
+   */
+  readonly versionArn?: string;
+
   /**
    * The underlying AWS Lambda function.
    */
@@ -47,6 +53,11 @@ export interface VersionAttributes {
    */
   readonly version: string;
 
+  /**
+   * The version arn.
+   */
+  readonly versionArn?: string;
+
   /**
    * The lambda function.
    */
@@ -80,6 +91,7 @@ export class Version extends Resource implements IVersion {
   }
 
   public readonly version: string;
+  public readonly versionArn?: string;
   public readonly lambda: IFunction;
 
   constructor(scope: Construct, id: string, props: VersionProps) {
@@ -92,6 +104,7 @@ export class Version extends Resource implements IVersion {
     });
 
     this.version = version.version;
+    this.versionArn = version.versionArn;
     this.lambda = props.lambda;
   }
 }