some changes to make this example independent of preexisting external APIs

Author: sobrab

java/http-proxy-apigateway/README.md

@@ -12,14 +12,15 @@
 <!--END STABILITY BANNER-->
 
 This example creates an API Gateway with proxy resources for 2 HTTP backends.
-More HTTP backend APIs can be easily added.
 This is useful for scenarios when incoming requests must be routed to one or more backend API hosts.
-An HTTP proxy integration enables direct interactions between clients and backends without any intervention from API Gateway after the API method is set up.
+An HTTP proxy integration enables direct interactions between clients and backends without any intervention from the API Gateway after the API method is set up.
 
 > For more information on using HTTP proxy integrations with the APIGateway check out this [AWS tutorial](https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-create-api-as-simple-proxy-for-http.html).
 
-> For demonstration purposes this CDK example deploys a solution that routes to the [PetsStore API](http://petstore-demo-endpoint.execute-api.com/) (from this [AWS tutorial](https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-create-api-as-simple-proxy-for-http.html)) and to the [OpenTrivia API](https://opentdb.com).
-> If you prefer to use your own HTTP backend APIs modify the argument used to call the [`HttpProxyApiGatewayStack`](src/main/java/com/myorg/HttpProxyApiGatewayStack.java) constructor in the [`HttpProxyApiGatewayApp`](src/main/java/com/myorg/HttpProxyApiGatewayApp.java) class.
+> For demonstration purposes this CDK example deploys a solution that routes to a couple of test HTTP APIs.
+> The 2 test HTTP APIs are implemented using lambdas exposed through function URLs.
+> This example can be modified though, if you prefer to use your own HTTP backend APIs.
+> To do that you can modify the `createHTTPTestAPIs` method in the [`HttpProxyApiGatewayStack`](src/main/java/com/myorg/HttpProxyApiGatewayStack.java) class to return a list of `ProxyResourceParameters` corresponding to your own resources.
 
 ## Build
 
@@ -37,12 +38,13 @@ This will install the necessary CDK, then this example's dependencies, and then
 
 Run `cdk deploy`.
 This will deploy / redeploy the Stack to AWS.
-After the CDK deployment is successful, 2 URL examples will be available in the terminal console output:
+After the CDK deployment is successful, 2 URL examples will be available in the terminal console:
 
-- One for the `PetStoreProxyEndPointGetRequestExample` stack output
-- One for the `OpenTriviaProxyEndPointGetRequestExample` stack output
+- One for the `HttpProxyApiGatewayStack.HelloFunctionResourceExample` output
+- One for the `HttpProxyApiGatewayStack.ByeFunctionResourceExample` output
 
 At this point, you can copy each of the 2 URLs and paste them in the address bar of a browser to invoke the 2 APIs.
+Also note that both URLs have the same host (the DNS of the new API Gateway created).
 
 ## Useful commands
 

java/http-proxy-apigateway/pom.xml

@@ -9,7 +9,7 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <cdk.version>2.167.1</cdk.version>
+        <cdk.version>2.171.1</cdk.version>
         <constructs.version>[10.0.0,11.0.0)</constructs.version>
         <junit.version>5.7.1</junit.version>
         <maven.compiler.target>22</maven.compiler.target>

java/http-proxy-apigateway/src/main/java/com/myorg/HttpProxyApiGatewayApp.java

@@ -2,28 +2,14 @@
 
 import software.amazon.awscdk.App;
 import software.amazon.awscdk.StackProps;
-import software.amazon.awscdk.services.apigatewayv2.HttpMethod;
-
-import java.util.List;
-
-import static com.myorg.HttpProxyApiGatewayStack.*;
 
 public class HttpProxyApiGatewayApp {
   public static void main(final String[] args) {
     var app = new App();
-    new HttpProxyApiGatewayStack(
-      app,
-      "HttpProxyApiGatewayStack",
-      StackProps.builder()
-        .stackName("HttpProxyApiGatewayStack")
-        .build(),
-      List.of(
-        // Replace with resources corresponding to your own HTTP backend APIs if you want to.
-        // Add more resources if you need to.
-        new ProxyResourceParameters("PetStore", "http://petstore-demo-endpoint.execute-api.com", HttpMethod.ANY.name(), "/petstore/pets?type=fish"),
-        new ProxyResourceParameters("OpenTrivia", "https://opentdb.com", HttpMethod.ANY.name(), "/api.php?amount=10")
-      )
-    );
+    var stackProps = StackProps.builder()
+      .stackName("HttpProxyApiGatewayStack")
+      .build();
+    new HttpProxyApiGatewayStack(app, "HttpProxyApiGatewayStack", stackProps);
     app.synth();
   }
 }

java/http-proxy-apigateway/src/main/java/com/myorg/HttpProxyApiGatewayStack.java

@@ -5,11 +5,19 @@
 import software.amazon.awscdk.Stack;
 import software.amazon.awscdk.StackProps;
 import software.amazon.awscdk.services.apigateway.*;
+import software.amazon.awscdk.services.lambda.*;
 import software.constructs.Construct;
 
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 
+import static software.amazon.awscdk.services.apigatewayv2.HttpMethod.ANY;
+import static software.amazon.awscdk.services.lambda.Runtime.PYTHON_3_12;
+
 public class HttpProxyApiGatewayStack extends Stack {
 
   public record ProxyResourceParameters(String resourceId, String baseUrl, String httpMethod, String exampleRequest) {
@@ -18,15 +26,49 @@ public record ProxyResourceParameters(String resourceId, String baseUrl, String
 
   private final RestApi restApi;
 
-  public HttpProxyApiGatewayStack(final Construct scope, final String id, final StackProps props, List<ProxyResourceParameters> proxyResourceParameters) {
+  public HttpProxyApiGatewayStack(final Construct scope, final String id, final StackProps props) {
     super(scope, id, props);
     restApi = RestApi.Builder.create(this, "RestApi")
       .restApiName("RestApi")
       .cloudWatchRole(true)
       .cloudWatchRoleRemovalPolicy(RemovalPolicy.DESTROY)
       .endpointTypes(List.of(EndpointType.EDGE))
       .build();
-    proxyResourceParameters.forEach(this::createProxyResource);
+    createHTTPTestAPIs().forEach(this::createProxyResource);
+  }
+
+  private List<ProxyResourceParameters> createHTTPTestAPIs() {
+    return Map.of(
+        "HelloFunction", "/hello?from=AWS",
+        "ByeFunction", "/bye?from=AWS"
+      ).entrySet().stream()
+      .map(functionEntry -> {
+        var functionName = functionEntry.getKey();
+        var parameters = functionEntry.getValue();
+        var function = Function.Builder.create(this, functionName)
+          .functionName(functionName)
+          .code(InlineCode.fromInline(getInlineCode("src/main/resources/lambdas/" + functionName + ".py")))
+          .handler("index.handler")
+          .runtime(PYTHON_3_12)
+          .build();
+        var lambdaFunctionAlias = Alias.Builder.create(this, functionName + "ProdAlias")
+          .aliasName("Prod")
+          .version(function.getCurrentVersion())
+          .build();
+        var functionURL = FunctionUrl.Builder.create(this, functionName + "Url")
+          .function(lambdaFunctionAlias)
+          .authType(FunctionUrlAuthType.NONE)
+          .invokeMode(InvokeMode.BUFFERED)
+          .cors(
+            FunctionUrlCorsOptions.builder()
+              .allowedOrigins(List.of("*"))
+              .allowedMethods(List.of(HttpMethod.GET))
+              .allowedHeaders(List.of("*"))
+              .build()
+          )
+          .build();
+        return new ProxyResourceParameters(functionName + "Resource", functionURL.getUrl(), ANY.name(), parameters);
+      }).collect(ArrayList::new, List::add, List::addAll);
   }
 
   private void createProxyResource(ProxyResourceParameters proxyResourceParameters) {
@@ -54,14 +96,22 @@ private void createProxyResource(ProxyResourceParameters proxyResourceParameters
         )
       )
       .build();
-    var httpIntegration = new HttpIntegration(proxyResourceParameters.baseUrl + "/{proxy}", httpIntegrationProps);
+    var httpIntegration = new HttpIntegration(proxyResourceParameters.baseUrl + "{proxy}", httpIntegrationProps);
     proxyResource.addMethod(proxyResourceParameters.httpMethod, httpIntegration, methodOptions);
     var proxyResourceUrl = restApi.urlForPath(proxyResource.getPath());
-    CfnOutput.Builder.create(this, proxyResourceParameters.resourceId + "ProxyEndPointAnyRequestTemplate")
+    CfnOutput.Builder.create(this, proxyResourceParameters.resourceId + "ProxyUrl")
       .value(proxyResourceUrl)
       .build();
-    CfnOutput.Builder.create(this, proxyResourceParameters.resourceId + "ProxyEndPointGetRequestExample")
+    CfnOutput.Builder.create(this, proxyResourceParameters.resourceId + "Example")
       .value(proxyResourceUrl.replace("/{proxy+}", proxyResourceParameters.exampleRequest))
       .build();
   }
+
+  private String getInlineCode(String path) {
+    try {
+      return new String(Files.readAllBytes(Path.of(path)));
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+  }
 }

java/http-proxy-apigateway/src/main/resources/lambdas/ByeFunction.py

@@ -0,0 +1,7 @@
+import json
+def handler(event, context):
+    fromValue = event.get('queryStringParameters', {}).get('from', 'Lambda')
+    return {
+        'statusCode': 200,
+        'body': json.dumps('Bye from ' + fromValue + '!')
+    }

java/http-proxy-apigateway/src/main/resources/lambdas/HelloFunction.py

@@ -0,0 +1,7 @@
+import json
+def handler(event, context):
+    fromValue = event.get('queryStringParameters', {}).get('from', 'Lambda')
+    return {
+        'statusCode': 200,
+        'body': json.dumps('Hello from ' + fromValue + '!')
+    }

java/http-proxy-apigateway/src/test/java/com/myorg/HttpProxyApiGatewayTest.java

@@ -10,12 +10,10 @@
 import software.amazon.awscdk.App;
 import software.amazon.awscdk.StackProps;
 import software.amazon.awscdk.cxapi.CloudFormationStackArtifact;
-import software.amazon.awscdk.services.apigatewayv2.HttpMethod;
 
 import java.util.*;
 import java.util.stream.Stream;
 
-import static com.myorg.HttpProxyApiGatewayStack.*;
 import static com.myorg.TestUtils.*;
 
 public class HttpProxyApiGatewayTest {
@@ -25,17 +23,10 @@ public class HttpProxyApiGatewayTest {
   @BeforeAll
   public static void setUp() {
     var app = App.Builder.create().build();
-    var httpProxyApiGatewayStack = new HttpProxyApiGatewayStack(
-      app,
-      "HttpProxyApiGatewayStack",
-      StackProps.builder()
-        .stackName("HttpProxyApiGatewayStack")
-        .build(),
-      List.of(
-        new ProxyResourceParameters("PetStore", "http://petstore-demo-endpoint.execute-api.com", HttpMethod.ANY.name(), "/petstore/pets?type=fish"),
-        new ProxyResourceParameters("OpenTrivia", "https://opentdb.com", HttpMethod.ANY.name(), "/api.php?amount=10")
-      )
-    );
+    var stackProps = StackProps.builder()
+      .stackName("HttpProxyApiGatewayStack")
+      .build();
+    var httpProxyApiGatewayStack = new HttpProxyApiGatewayStack(app, "HttpProxyApiGatewayStack", stackProps);
     Optional.of(app)
       .map(App::synth)
       .flatMap(
@@ -74,7 +65,7 @@ public void testRestApi() {
 
   @Test
   @DisplayName("Test if the expected IAM role for the REST API is present in the resources of the stack.")
-  public void testIamRole() {
+  public void testRestAPIIamRole() {
     var iamRoleMatchMap = Map.of(
       "/Type", "AWS::IAM::Role",
       "/Properties/AssumeRolePolicyDocument/Statement/0/Action", "sts:AssumeRole",
@@ -98,7 +89,16 @@ public void testApiGatewayAccount() {
     );
     var restApiId = findResourceId(stackResourcesMap, restApiMatchMap);
     var iamRoleMatchMap = Map.of(
-      "/Type", "AWS::IAM::Role"
+      "/Type", "AWS::IAM::Role",
+      "/Properties/AssumeRolePolicyDocument/Statement/0/Action", "sts:AssumeRole",
+      "/Properties/AssumeRolePolicyDocument/Statement/0/Effect", "Allow",
+      "/Properties/AssumeRolePolicyDocument/Statement/0/Principal/Service", "apigateway.amazonaws.com",
+      "/Properties/AssumeRolePolicyDocument/Version", "2012-10-17",
+      "/Properties/ManagedPolicyArns/0/Fn::Join/0", "",
+      "/Properties/ManagedPolicyArns/0/Fn::Join/1/0", "arn:",
+      "/Properties/ManagedPolicyArns/0/Fn::Join/1/1/Ref", "AWS::Partition",
+      "/Properties/ManagedPolicyArns/0/Fn::Join/1/2", ":iam::aws:policy/service-role/AmazonAPIGatewayPushToCloudWatchLogs",
+      "/DeletionPolicy", "Delete"
     );
     var iamRoleId = findResourceId(stackResourcesMap, iamRoleMatchMap);
     var apiGatewayAccountMatchMap = Map.of(
@@ -199,13 +199,134 @@ public void testApiGatewayMethods() {
       "/Properties/RequestParameters/method.request.path.proxy", "true",
       "/Properties/RestApiId/Ref", restApiId
     );
-    Long expectedPermissionsCount = 2L;
+    Long expectedApiGatewayMethodsCount = 2L;
     Assertions.assertTrue(
       Optional.ofNullable(findResources(stackResourcesMap, apiGatewayMethodsMatchMap))
         .map(Map::entrySet)
         .map(Set::stream)
         .map(Stream::count)
-        .filter(methodsCont -> methodsCont.equals(expectedPermissionsCount))
+        .filter(methodsCont -> methodsCont.equals(expectedApiGatewayMethodsCount))
+        .isPresent()
+    );
+  }
+
+  @Test
+  @DisplayName("Test if the expected IAM roles for the test lambdas are present in the resources of the stack.")
+  public void testLambdaFunctionsIAMRoles() {
+    var lambdaFunctionsIAMRolesMatchMap = Map.of(
+      "/Type", "AWS::IAM::Role",
+      "/Properties/AssumeRolePolicyDocument/Statement/0/Action", "sts:AssumeRole",
+      "/Properties/AssumeRolePolicyDocument/Statement/0/Effect", "Allow",
+      "/Properties/AssumeRolePolicyDocument/Statement/0/Principal/Service", "lambda.amazonaws.com",
+      "/Properties/AssumeRolePolicyDocument/Version", "2012-10-17",
+      "/Properties/ManagedPolicyArns/0/Fn::Join/0", "",
+      "/Properties/ManagedPolicyArns/0/Fn::Join/1/0", "arn:",
+      "/Properties/ManagedPolicyArns/0/Fn::Join/1/1/Ref", "AWS::Partition",
+      "/Properties/ManagedPolicyArns/0/Fn::Join/1/2", ":iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
+    );
+    Long expectedLambdaFunctionsIAMRolesCount = 2L;
+    Assertions.assertTrue(
+      Optional.ofNullable(findResources(stackResourcesMap, lambdaFunctionsIAMRolesMatchMap))
+        .map(Map::entrySet)
+        .map(Set::stream)
+        .map(Stream::count)
+        .filter(methodsCont -> methodsCont.equals(expectedLambdaFunctionsIAMRolesCount))
+        .isPresent()
+    );
+  }
+
+  @Test
+  @DisplayName("Test if the expected lambda functions are present in the resources of the stack.")
+  public void testLambdaFunctions() {
+    var lambdaFunctionsMatchMap = Map.of(
+      "/Type", "AWS::Lambda::Function",
+      "/Properties/Runtime", "python3.12"
+    );
+    Long expectedLambdaFunctionsCount = 2L;
+    Assertions.assertTrue(
+      Optional.ofNullable(findResources(stackResourcesMap, lambdaFunctionsMatchMap))
+        .map(Map::entrySet)
+        .map(Set::stream)
+        .map(Stream::count)
+        .filter(methodsCont -> methodsCont.equals(expectedLambdaFunctionsCount))
+        .isPresent()
+    );
+  }
+
+  @Test
+  @DisplayName("Test if the expected lambda versions are present in the resources of the stack.")
+  public void testLambdaVersions() {
+    var lambdaVersionsMatchMap = Map.of(
+      "/Type", "AWS::Lambda::Version"
+    );
+    Long expectedLambdaVersionsCount = 2L;
+    Assertions.assertTrue(
+      Optional.ofNullable(findResources(stackResourcesMap, lambdaVersionsMatchMap))
+        .map(Map::entrySet)
+        .map(Set::stream)
+        .map(Stream::count)
+        .filter(methodsCont -> methodsCont.equals(expectedLambdaVersionsCount))
+        .isPresent()
+    );
+  }
+
+  @Test
+  @DisplayName("Test if the expected lambda aliases are present in the resources of the stack.")
+  public void testLambdaAliases() {
+    var lambdaAliasesMatchMap = Map.of(
+      "/Type", "AWS::Lambda::Alias",
+      "/Properties/Name", "Prod"
+    );
+    Long expectedLambdaAliasesCount = 2L;
+    Assertions.assertTrue(
+      Optional.ofNullable(findResources(stackResourcesMap, lambdaAliasesMatchMap))
+        .map(Map::entrySet)
+        .map(Set::stream)
+        .map(Stream::count)
+        .filter(methodsCont -> methodsCont.equals(expectedLambdaAliasesCount))
+        .isPresent()
+    );
+  }
+
+  @Test
+  @DisplayName("Test if the expected lambda permissions are present in the resources of the stack.")
+  public void testLambdaPermissions() {
+    var lambdaPermissionsMatchMap = Map.of(
+      "/Type", "AWS::Lambda::Permission",
+      "/Properties/Action", "lambda:InvokeFunctionUrl",
+      "/Properties/FunctionUrlAuthType", "NONE",
+      "/Properties/Principal", "*"
+    );
+    Long expectedLambdaPermissionsCount = 2L;
+    Assertions.assertTrue(
+      Optional.ofNullable(findResources(stackResourcesMap, lambdaPermissionsMatchMap))
+        .map(Map::entrySet)
+        .map(Set::stream)
+        .map(Stream::count)
+        .filter(methodsCont -> methodsCont.equals(expectedLambdaPermissionsCount))
+        .isPresent()
+    );
+  }
+
+  @Test
+  @DisplayName("Test if the expected lambda function URLs are present in the resources of the stack.")
+  public void testLambdaFunctionURLs() {
+    var lambdaFunctionsURLsMatchMap = Map.of(
+      "/Type", "AWS::Lambda::Url",
+      "/Properties/AuthType", "NONE",
+      "/Properties/InvokeMode", "BUFFERED",
+      "/Properties/Qualifier", "Prod",
+      "/Properties/Cors/AllowHeaders/0", "*",
+      "/Properties/Cors/AllowMethods/0", "GET",
+      "/Properties/Cors/AllowOrigins/0", "*"
+    );
+    Long expectedLambdaFunctionsURLsCount = 2L;
+    Assertions.assertTrue(
+      Optional.ofNullable(findResources(stackResourcesMap, lambdaFunctionsURLsMatchMap))
+        .map(Map::entrySet)
+        .map(Set::stream)
+        .map(Stream::count)
+        .filter(methodsCont -> methodsCont.equals(expectedLambdaFunctionsURLsCount))
         .isPresent()
     );
   }