Add AWS Lambda CloudFront Event origin fields. (#28675)

* Add AWS Lambda CloudFront Event origin fields.

* Add tests for the different kinds of Lambda CloudFrontRequests.

types/aws-lambda/aws-lambda-tests.ts

@@ -581,7 +581,7 @@ const CodePipelineEvent: AWSLambda.CodePipelineEvent = {
 CodePipelineEvent["CodePipeline.job"].data.encryptionKey = { type: 'KMS', id: 'key' };
 
 /* CloudFront events, see http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/lambda-event-structure.html */
-const CloudFrontRequestEvent: AWSLambda.CloudFrontRequestEvent = {
+const CloudFrontRequestWithCustomOriginEvent: AWSLambda.CloudFrontRequestEvent = {
   Records: [
     {
       cf: {
@@ -630,7 +630,44 @@ const CloudFrontRequestEvent: AWSLambda.CloudFrontRequestEvent = {
                 "TLSv1",
                 "TLSv1.1"
               ]
-            },
+            }
+          }
+        }
+      }
+    }
+  ]
+};
+
+const CloudFrontRequestWithS3OriginEvent: AWSLambda.CloudFrontRequestEvent = {
+  Records: [
+    {
+      cf: {
+        config: {
+          distributionDomainName: "d123.cloudfront.net",
+          distributionId: "EDFDVBD6EXAMPLE",
+          eventType: "viewer-request",
+          requestId: "MRVMF7KydIvxMWfJIglgwHQwZsbG2IhRJ07sn9AkKUFSHS9EXAMPLE=="
+        },
+        request: {
+          clientIp: "2001:0db8:85a3:0:0:8a2e:0370:7334",
+          method: "GET",
+          uri: "/picture.jpg",
+          querystring: "size=large",
+          headers: {
+            host: [
+              {
+                key: "Host",
+                value: "d111111abcdef8.cloudfront.net"
+              }
+            ],
+            "user-agent": [
+              {
+                key: "User-Agent",
+                value: "curl/7.51.0"
+              }
+            ]
+          },
+          origin: {
             s3: {
               authMethod: "origin-access-identity",
               customHeaders: {
@@ -812,6 +849,56 @@ apiGtwProxyHandler = proxyHandler;
 const codePipelineHandler: AWSLambda.CodePipelineHandler = (event: AWSLambda.CodePipelineEvent, context: AWSLambda.Context, cb: AWSLambda.Callback<void>) => {};
 
 const cloudFrontRequestHandler: AWSLambda.CloudFrontRequestHandler = (event: AWSLambda.CloudFrontRequestEvent, context: AWSLambda.Context, cb: AWSLambda.CloudFrontRequestCallback) => {
+    event = CloudFrontRequestWithCustomOriginEvent;
+    // $ExpectType CloudFrontRequestEvent
+    event;
+    let request = event.Records[0].cf.request;
+
+    let s3Origin: AWSLambda.CloudFrontS3Origin = {
+        authMethod: 'none',
+        customHeaders: {},
+        domainName: 'example.com',
+        path: '/',
+        region: 'us-east-1'
+    };
+
+    if (request.origin && request.origin.custom) {
+        request.origin.custom.domainName;
+        request.origin.custom.domainName = "example2.com";
+
+        // $ExpectError
+        s3Origin = request.origin.s3;
+
+        // $ExpectError
+        request.origin.s3.path = '/';
+    }
+
+    let customOrigin: AWSLambda.CloudFrontCustomOrigin = {
+        customHeaders: {},
+        domainName: 'example.com',
+        keepaliveTimeout: 60,
+        path: '/',
+        port: 80,
+        protocol: 'http',
+        readTimeout: 30,
+        sslProtocols: []
+    };
+
+    event = CloudFrontRequestWithS3OriginEvent;
+    // $ExpectType CloudFrontRequestEvent
+    event;
+    request = event.Records[0].cf.request;
+    if (request.origin && request.origin.s3) {
+        request.origin.s3.path;
+        request.origin.s3.path = "/new_path";
+
+        // $ExpectError
+        customOrigin = request.origin.custom;
+
+        // $ExpectError
+        request.origin.custom.path = '/';
+    }
+
     cb();
     cb(null);
     cb(new Error(''));

types/aws-lambda/index.d.ts

@@ -21,6 +21,7 @@
 //                 Jeremy Nagel <https://github.com/jeznag>
 //                 Louis Larry <https://github.com/louislarry>
 //                 Daniel Papukchiev <https://github.com/dpapukchiev>
+//                 Oliver Hookins <https://github.com/ohookins>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.3
 
@@ -561,6 +562,9 @@ export interface CodePipelineEvent {
 /**
  * CloudFront events
  * http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/lambda-event-structure.html
+ * Bear in mind that the "example" event structure in the page above includes
+ * both an S3 and a Custom origin, which is not strictly allowed. Only one
+ * of these per event may be present.
  */
 export interface CloudFrontHeaders {
     [name: string]: Array<{
@@ -569,6 +573,29 @@ export interface CloudFrontHeaders {
     }>;
 }
 
+export type CloudFrontOrigin =
+    | { s3: CloudFrontS3Origin, custom?: never }
+    | { custom: CloudFrontCustomOrigin, s3?: never };
+
+export interface CloudFrontCustomOrigin {
+    customHeaders: CloudFrontHeaders;
+    domainName: string;
+    keepaliveTimeout: number;
+    path: string;
+    port: number;
+    protocol: 'http' | 'https';
+    readTimeout: number;
+    sslProtocols: string[];
+}
+
+export interface CloudFrontS3Origin {
+    authMethod: 'origin-access-identity' | 'none';
+    customHeaders: CloudFrontHeaders;
+    domainName: string;
+    path: string;
+    region: string;
+}
+
 export interface CloudFrontResponse {
     status: string;
     statusDescription: string;
@@ -581,6 +608,7 @@ export interface CloudFrontRequest {
     uri: string;
     querystring: string;
     headers: CloudFrontHeaders;
+    origin?: CloudFrontOrigin;
 }
 
 export interface CloudFrontEvent {