Implemented feature

source/patterns/@aws-solutions-constructs/aws-openapigateway-lambda/lib/index.ts

@@ -126,14 +126,15 @@ export class OpenApiGatewayToLambda extends Construct {
           lambdaFunction: defaults.buildLambdaFunction(this, {
             existingLambdaObj: apiIntegration.existingLambdaObj,
             lambdaFunctionProps: apiIntegration.lambdaFunctionProps
-          }, `${apiIntegration.id}ApiFunction${lambdaCounter++}`)
+          }, `${apiIntegration.id}ApiFunction${lambdaCounter++}`),
+          functionAlias: apiIntegration.existingFunctionAlias
         };
       } else {
         throw new Error(`One of existingLambdaObj or lambdaFunctionProps must be specified for the api integration with id: ${apiIntegration.id}`);
       }
     });
 
-    const definition = ObtainApiDefinition(this,  {
+    const definition = ObtainApiDefinition(this, {
       tokenToFunctionMap: this.apiLambdaFunctions,
       apiDefinitionBucket: props.apiDefinitionBucket,
       apiDefinitionKey: props.apiDefinitionKey,
@@ -157,11 +158,19 @@ export class OpenApiGatewayToLambda extends Construct {
     this.apiLambdaFunctions.forEach(apiLambdaFunction => {
       // Redeploy the API any time one of the lambda functions changes
       this.apiGateway.latestDeployment?.addToLogicalId(apiLambdaFunction.lambdaFunction.functionArn);
-      // Grant APIGW invocation rights for each lambda function
-      apiLambdaFunction.lambdaFunction.addPermission(`${id}PermitAPIGInvocation`, {
-        principal: new iam.ServicePrincipal('apigateway.amazonaws.com'),
-        sourceArn: this.apiGateway.arnForExecuteApi('*')
-      });
+      if (apiLambdaFunction.functionAlias) {
+        // Grant APIGW invocation rights for each lambda function
+        apiLambdaFunction.functionAlias.addPermission(`${id}PermitAPIGInvocation`, {
+          principal: new iam.ServicePrincipal('apigateway.amazonaws.com'),
+          sourceArn: this.apiGateway.arnForExecuteApi('*')
+        });
+      } else {
+        // Grant APIGW invocation rights for each lambda function
+        apiLambdaFunction.lambdaFunction.addPermission(`${id}PermitAPIGInvocation`, {
+          principal: new iam.ServicePrincipal('apigateway.amazonaws.com'),
+          sourceArn: this.apiGateway.arnForExecuteApi('*')
+        });
+      }
     });
   }
 }

source/patterns/@aws-solutions-constructs/aws-openapigateway-lambda/lib/openapi-helper.ts

@@ -48,6 +48,12 @@ export interface ApiIntegration {
    * One and only one of existingLambdaObj or lambdaFunctionProps must be specified, any other combination will cause an error.
    */
   readonly existingLambdaObj?: lambda.Function;
+  /**
+   * An Alias to the provided existingLambdbaObj that should be used in the integration with the API
+   *
+   * This is only valid if and existingLambdaObj is specified
+   */
+  readonly existingFunctionAlias?: lambda.Alias;
   /**
    * Properties for the Lambda function to create and associate with the API method in the OpenAPI file matched by id.
    *
@@ -68,6 +74,10 @@ export interface ApiLambdaFunction {
    * The instantiated lambda.Function.
    */
   readonly lambdaFunction: lambda.Function;
+  /**
+   * Optional Alias to the function - if provided, it will be used instead of the function whereever possible.
+   */
+  readonly functionAlias?: lambda.Alias;
 }
 
 export interface OpenApiProps {
@@ -136,7 +146,8 @@ export function ObtainApiDefinition(scope: Construct, props: ObtainApiDefinition
     const uriPlaceholderString = apiLambdaFunction.id;
     // the endpoint URI of the backing lambda function, as defined in the API Gateway extensions for OpenAPI here:
     // https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-swagger-extensions-integration.html
-    const uriResolvedValue = `arn:${Aws.PARTITION}:apigateway:${Aws.REGION}:lambda:path/2015-03-31/functions/${apiLambdaFunction.lambdaFunction.functionArn}/invocations`;
+    const targetArn = apiLambdaFunction.functionAlias ? apiLambdaFunction.functionAlias.functionArn : apiLambdaFunction.lambdaFunction.functionArn;
+    const uriResolvedValue = `arn:${Aws.PARTITION}:apigateway:${Aws.REGION}:lambda:path/2015-03-31/functions/${targetArn}/invocations`;
 
     return {
       id: uriPlaceholderString,

source/patterns/@aws-solutions-constructs/aws-openapigateway-lambda/test/integ.opilam-apiFromAssetLambdaFunctionAliases.js.snapshot/asset.0ac0535f48d1ada09cde7f11fc72195d9d32da75a2719aeb20c4e5c45b28e62e/index.mjs

@@ -0,0 +1,16 @@
+export const handler = async (event) => {
+  switch (event.httpMethod) {
+    case 'POST':
+      return {
+        statusCode: 200,
+        body: JSON.stringify({"message": "NEW - successfully handled POST from messages lambda"})
+      };
+    case 'GET':
+      return {
+        statusCode: 200,
+        body: JSON.stringify({"message": "NEW - successfully handled GET from messages lambda"})
+      };
+    default:
+      throw new Error(`cannot handle httpMethod: ${event.httpMethod}`);
+  }
+};

source/patterns/@aws-solutions-constructs/aws-openapigateway-lambda/test/integ.opilam-apiFromAssetLambdaFunctionAliases.js.snapshot/asset.37a6f0964e9c5c4133e01db00bbcaebc6da2a25a21e27aa0f87add1eb65546e7/index.ts

@@ -0,0 +1,73 @@
+/**
+ *  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file except in compliance
+ *  with the License. A copy of the License is located at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  or in the 'license' file accompanying this file. This file is distributed on an 'AS IS' BASIS, WITHOUT WARRANTIES
+ *  OR CONDITIONS OF ANY KIND, express or implied. See the License for the specific language governing permissions
+ *  and limitations under the License.
+ */
+
+import { S3Client, GetObjectCommand, PutObjectCommand } from "@aws-sdk/client-s3";
+import * as crypto from 'crypto';
+
+const s3Client = new S3Client({ region: process.env.REGION });
+
+export const handler = async (event: any, context: any) => {
+  let status = 'SUCCESS';
+  let responseData = {};
+
+  // These are the standard Create/Update/Delete custom resource request types defined here:
+  // https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/crpg-ref-requesttypes.html
+  if (event.RequestType === 'Create' || event.RequestType === 'Update') {
+    try {
+      const templateValues = JSON.parse(event.ResourceProperties.TemplateValues).templateValues;
+      const templateInputBucket = event.ResourceProperties.TemplateInputBucket;
+      const templateInputKey = event.ResourceProperties.TemplateInputKey;
+      const templateOutputBucket = event.ResourceProperties.TemplateOutputBucket;
+      const templateOutputKey = crypto.randomBytes(32).toString('hex');
+
+      const getObjectResponse = await s3Client.send(new GetObjectCommand({
+        Bucket: templateInputBucket,
+        Key: templateInputKey
+      }));
+
+      let template = await getObjectResponse.Body?.transformToString();
+
+      templateValues.forEach((templateValue: any) => {
+        template = template?.replace(
+          new RegExp(templateValue.id, 'g'),
+          templateValue.value
+        );
+      });
+
+      await s3Client.send(new PutObjectCommand({
+        Bucket: templateOutputBucket,
+        Key: templateOutputKey,
+        Body: template
+      }));
+
+      responseData = {
+        TemplateOutputKey: templateOutputKey
+      };
+    } catch (err) {
+      status = 'FAILED';
+      responseData = {
+        Error: err
+      };
+    }
+  }
+
+  return {
+    Status: status,
+    Reason: JSON.stringify(responseData),
+    PhysicalResourceId: event.PhysicalResourceId ?? context.logStreamName,
+    StackId: event.StackId,
+    RequestId: event.RequestId,
+    LogicalResourceId: event.LogicalResourceId,
+    Data: responseData,
+  };
+};

source/patterns/@aws-solutions-constructs/aws-openapigateway-lambda/test/integ.opilam-apiFromAssetLambdaFunctionAliases.js.snapshot/asset.654d49d4ea47a6be417d57b94dc0310933d0e971a3e48a3080c3e48487af3e50/index.mjs

@@ -0,0 +1,16 @@
+export const handler = async (event) => {
+  switch (event.httpMethod) {
+    case 'POST':
+      return {
+        statusCode: 200,
+        body: JSON.stringify({"message": "successfully handled POST from photos lambda"})
+      };
+    case 'GET':
+      return {
+        statusCode: 200,
+        body: JSON.stringify({"message": "successfully handled GET from photos lambda"})
+      };
+    default:
+      throw new Error(`cannot handle httpMethod: ${event.httpMethod}`);
+  }
+};

source/patterns/@aws-solutions-constructs/aws-openapigateway-lambda/test/integ.opilam-apiFromAssetLambdaFunctionAliases.js.snapshot/asset.7dbcd6245c5c6f70da313d31e9bd533af2214c565d855fb2f669666e927c125e

@@ -0,0 +1,3 @@
+DO-NOT-DELETE
+
+This file is used to create an aws_s3_assets.Asset that will be referenced when writing the transformed asset.