feat(cloudfront): allow to specify stack ID for Lambda@Edge (#12163)

Closes #12136

----

*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/README.md

@@ -286,6 +286,25 @@ const myFunc = new lambda.Function(this, 'MyFunction', {
 });
 ```
 
+If the stack is not in `us-east-1`, and you need references from different applications on the same account,
+you can also set a specific stack ID for each Lamba@Edge.
+
+```ts
+const myFunc1 = new cloudfront.experimental.EdgeFunction(this, 'MyFunction1', {
+  runtime: lambda.Runtime.NODEJS_10_X,
+  handler: 'index.handler',
+  code: lambda.Code.fromAsset(path.join(__dirname, 'lambda-handler1')),
+  stackId: 'edge-lambda-stack-id-1'
+});
+
+const myFunc2 = new cloudfront.experimental.EdgeFunction(this, 'MyFunction2', {
+  runtime: lambda.Runtime.NODEJS_10_X,
+  handler: 'index.handler',
+  code: lambda.Code.fromAsset(path.join(__dirname, 'lambda-handler2')),
+  stackId: 'edge-lambda-stack-id-2'
+});
+```
+
 Lambda@Edge functions can also be associated with additional behaviors,
 either at or after Distribution creation time.
 

packages/@aws-cdk/aws-cloudfront/lib/experimental/edge-function.ts

@@ -16,7 +16,14 @@ import { Construct } from 'constructs';
  * Properties for creating a Lambda@Edge function
  * @experimental
  */
-export interface EdgeFunctionProps extends lambda.FunctionProps { }
+export interface EdgeFunctionProps extends lambda.FunctionProps {
+  /**
+   * The stack ID of Lambda@Edge function.
+   *
+   * @default - `edge-lambda-stack-${region}`
+   */
+  readonly stackId?: string;
+}
 
 /**
  * A Lambda@Edge function.
@@ -139,10 +146,10 @@ export class EdgeFunction extends Resource implements lambda.IVersion {
   }
 
   /** Create a support stack and function in us-east-1, and a SSM reader in-region */
-  private createCrossRegionFunction(id: string, props: lambda.FunctionProps): FunctionConfig {
+  private createCrossRegionFunction(id: string, props: EdgeFunctionProps): FunctionConfig {
     const parameterNamePrefix = 'EdgeFunctionArn';
     const parameterName = `${parameterNamePrefix}${id}`;
-    const functionStack = this.edgeStack();
+    const functionStack = this.edgeStack(props.stackId);
 
     const edgeFunction = new lambda.Function(functionStack, id, props);
     addEdgeLambdaToRoleTrustStatement(edgeFunction.role!);
@@ -193,7 +200,7 @@ export class EdgeFunction extends Resource implements lambda.IVersion {
     return resource.getAttString('FunctionArn');
   }
 
-  private edgeStack(): Stack {
+  private edgeStack(stackId?: string): Stack {
     const stage = this.node.root;
     if (!stage || !Stage.isStage(stage)) {
       throw new Error('stacks which use EdgeFunctions must be part of a CDK app or stage');
@@ -203,7 +210,7 @@ export class EdgeFunction extends Resource implements lambda.IVersion {
       throw new Error('stacks which use EdgeFunctions must have an explicitly set region');
     }
 
-    const edgeStackId = `edge-lambda-stack-${region}`;
+    const edgeStackId = stackId ?? `edge-lambda-stack-${region}`;
     let edgeStack = stage.node.tryFindChild(edgeStackId) as Stack;
     if (!edgeStack) {
       edgeStack = new Stack(stage, edgeStackId, {

packages/@aws-cdk/aws-cloudfront/test/experimental/edge-function.test.ts

@@ -146,6 +146,18 @@ describe('stacks', () => {
     const fnStack = getFnStack();
     expect(fnStack).toCountResources('AWS::Lambda::Function', 2);
   });
+
+  test('can set the stack id for each function', () => {
+    const fn1StackId = 'edge-lambda-stack-testregion-1';
+    new cloudfront.experimental.EdgeFunction(stack, 'MyFn1', defaultEdgeFunctionProps(fn1StackId));
+    const fn2StackId = 'edge-lambda-stack-testregion-2';
+    new cloudfront.experimental.EdgeFunction(stack, 'MyFn2', defaultEdgeFunctionProps(fn2StackId));
+
+    const fn1Stack = app.node.findChild(fn1StackId) as cdk.Stack;
+    expect(fn1Stack).toCountResources('AWS::Lambda::Function', 1);
+    const fn2Stack = app.node.findChild(fn2StackId) as cdk.Stack;
+    expect(fn2Stack).toCountResources('AWS::Lambda::Function', 1);
+  });
 });
 
 test('addAlias() creates alias in function stack', () => {
@@ -189,11 +201,12 @@ test('metric methods', () => {
   }
 });
 
-function defaultEdgeFunctionProps() {
+function defaultEdgeFunctionProps(stackId?: string) {
   return {
     code: lambda.Code.fromInline('foo'),
     handler: 'index.handler',
     runtime: lambda.Runtime.NODEJS_12_X,
+    stackId: stackId ?? 'edge-lambda-stack-testregion',
   };
 }
 

packages/@aws-cdk/aws-cloudfront/test/integ.distribution-lambda-cross-region.expected.json

@@ -127,6 +127,22 @@
           "CustomCrossRegionStringParameterReaderCustomResourceProviderRole71CD6825"
         ]
       },
+      "Lambda2ArnReader5ACFBE1F": {
+        "Type": "Custom::CrossRegionStringParameterReader",
+        "Properties": {
+          "ServiceToken": {
+            "Fn::GetAtt": [
+              "CustomCrossRegionStringParameterReaderCustomResourceProviderHandler65B5F33A",
+              "Arn"
+            ]
+          },
+          "Region": "us-east-1",
+          "ParameterName": "EdgeFunctionArnLambda2",
+          "RefreshToken": "8f81ceb404ac454f09648e62822d9ca9"
+        },
+        "UpdateReplacePolicy": "Delete",
+        "DeletionPolicy": "Delete"
+      },
       "DistB3B78991": {
         "Type": "AWS::CloudFront::Distribution",
         "Properties": {
@@ -162,6 +178,42 @@
             ]
           }
         }
+      },
+      "Dist286EC08DF": {
+        "Type": "AWS::CloudFront::Distribution",
+        "Properties": {
+          "DistributionConfig": {
+            "DefaultCacheBehavior": {
+              "CachePolicyId": "4135ea2d-6df8-44a3-9df3-4b5a84be39ad",
+              "Compress": true,
+              "LambdaFunctionAssociations": [
+                {
+                  "EventType": "origin-request",
+                  "LambdaFunctionARN": {
+                    "Fn::GetAtt": [
+                      "Lambda2ArnReader5ACFBE1F",
+                      "FunctionArn"
+                    ]
+                  }
+                }
+              ],
+              "TargetOriginId": "integdistributionlambdacrossregionDist2Origin14F08376D",
+              "ViewerProtocolPolicy": "allow-all"
+            },
+            "Enabled": true,
+            "HttpVersion": "http2",
+            "IPV6Enabled": true,
+            "Origins": [
+              {
+                "CustomOriginConfig": {
+                  "OriginProtocolPolicy": "https-only"
+                },
+                "DomainName": "www.example2.com",
+                "Id": "integdistributionlambdacrossregionDist2Origin14F08376D"
+              }
+            ]
+          }
+        }
       }
     },
     "Parameters": {
@@ -257,5 +309,84 @@
         }
       }
     }
+  },
+  {
+    "Resources": {
+      "Lambda2ServiceRole31A072E1": {
+        "Type": "AWS::IAM::Role",
+        "Properties": {
+          "AssumeRolePolicyDocument": {
+            "Statement": [
+              {
+                "Action": "sts:AssumeRole",
+                "Effect": "Allow",
+                "Principal": {
+                  "Service": "lambda.amazonaws.com"
+                }
+              },
+              {
+                "Action": "sts:AssumeRole",
+                "Effect": "Allow",
+                "Principal": {
+                  "Service": "edgelambda.amazonaws.com"
+                }
+              }
+            ],
+            "Version": "2012-10-17"
+          },
+          "ManagedPolicyArns": [
+            {
+              "Fn::Join": [
+                "",
+                [
+                  "arn:",
+                  {
+                    "Ref": "AWS::Partition"
+                  },
+                  ":iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
+                ]
+              ]
+            }
+          ]
+        }
+      },
+      "Lambda217CFB423": {
+        "Type": "AWS::Lambda::Function",
+        "Properties": {
+          "Code": {
+            "ZipFile": "foo"
+          },
+          "Handler": "index.handler",
+          "Role": {
+            "Fn::GetAtt": [
+              "Lambda2ServiceRole31A072E1",
+              "Arn"
+            ]
+          },
+          "Runtime": "nodejs10.x"
+        },
+        "DependsOn": [
+          "Lambda2ServiceRole31A072E1"
+        ]
+      },
+      "Lambda2CurrentVersion72012B74b9eef8becb98501bc795baca3c6169c4": {
+        "Type": "AWS::Lambda::Version",
+        "Properties": {
+          "FunctionName": {
+            "Ref": "Lambda217CFB423"
+          }
+        }
+      },
+      "Lambda2Parameter3444E17A": {
+        "Type": "AWS::SSM::Parameter",
+        "Properties": {
+          "Type": "String",
+          "Value": {
+            "Ref": "Lambda2CurrentVersion72012B74b9eef8becb98501bc795baca3c6169c4"
+          },
+          "Name": "EdgeFunctionArnLambda2"
+        }
+      }
+    }
   }
 ]

packages/@aws-cdk/aws-cloudfront/test/integ.distribution-lambda-cross-region.ts

@@ -5,14 +5,23 @@ import * as cloudfront from '../lib';
 import { TestOrigin } from './test-origin';
 
 const app = new cdk.App();
-const stack = new cdk.Stack(app, 'integ-distribution-lambda-cross-region', { env: { region: 'eu-west-1' } });
+
+const region = 'eu-west-1';
+const stack = new cdk.Stack(app, 'integ-distribution-lambda-cross-region', { env: { region: region } });
 
 const lambdaFunction = new cloudfront.experimental.EdgeFunction(stack, 'Lambda', {
   code: lambda.Code.fromInline('foo'),
   handler: 'index.handler',
   runtime: lambda.Runtime.NODEJS_10_X,
 });
 
+const lambdaFunction2 = new cloudfront.experimental.EdgeFunction(stack, 'Lambda2', {
+  code: lambda.Code.fromInline('foo'),
+  handler: 'index.handler',
+  runtime: lambda.Runtime.NODEJS_10_X,
+  stackId: `edge-lambda-stack-${region}-2`,
+});
+
 new cloudfront.Distribution(stack, 'Dist', {
   defaultBehavior: {
     origin: new TestOrigin('www.example.com'),
@@ -24,4 +33,15 @@ new cloudfront.Distribution(stack, 'Dist', {
   },
 });
 
+new cloudfront.Distribution(stack, 'Dist2', {
+  defaultBehavior: {
+    origin: new TestOrigin('www.example2.com'),
+    cachePolicy: cloudfront.CachePolicy.CACHING_DISABLED,
+    edgeLambdas: [{
+      functionVersion: lambdaFunction2.currentVersion,
+      eventType: cloudfront.LambdaEdgeEventType.ORIGIN_REQUEST,
+    }],
+  },
+});
+
 app.synth();