APIGW + Lambda sample app (#961)

sample-apps/apigateway-lambda/README.md

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+## API Gateway + Lambda Sample Application
+
+The directory contains the source code and the Infrastructure as Code (IaC) to create the sample app in your AWS account.
+
+### Prerequisite
+Before you begin, ensure you have the following installed:
+- Java 17
+- Gradle
+- Terraform
+- AWS CLI configured with appropriate credentials
+
+### Getting Started
+
+#### 1. Build the application
+```bash
+# Change to the project directory
+cd sample-apps/apigateway-lambda
+
+# Build the application using Gradle
+gradle clean build
+
+# Prepare the Lambda deployment package
+gradle createLambdaZip
+```
+
+#### 2. Deploy the application
+```bash
+# Change to the terraform directory
+cd terraform
+
+# Initialize Terraform
+terraform init
+
+# (Optional) Review the deployment plan for better understanding of the components
+terraform plan
+
+# Deploy
+terraform apply
+```
+
+#### 3. Testing the applicating
+After successful deployment, Terraform will output the API Gateway endpoint URL. You can test the application using:
+```bash
+curl <API_Gateway_URL>
+```
+
+#### 4. Clean Up
+To avoid incurring unnecessary charges, remember to destroy the resources when you are done:
+```bash
+terraform destroy
+```
+
+#### (Optional) Instrumenting with Application Signals Lambda Layer
+You can choose to instrument the Lambda function with Application Signals Lambda Layer upon deployment by passing in the layer ARN to the `adot_layer_arn` variable.
+You must have the layer already published to your account before executing the following command.
+```bash
+terraform apply -var "adot_layer_arn=<APPLICATION_SIGNALS_LAYER_FULL_ARN_WITH_VERSION>"
+```

sample-apps/apigateway-lambda/build.gradle.kts

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+plugins {
+  java
+  application
+}
+
+application {
+  mainClass.set("com.amazon.sampleapp.LambdaHandler")
+}
+
+java {
+  toolchain {
+    languageVersion.set(JavaLanguageVersion.of(17))
+  }
+}
+
+dependencies {
+  implementation("com.amazonaws:aws-lambda-java-core:1.2.2")
+  implementation("com.squareup.okhttp3:okhttp:4.11.0")
+  implementation("software.amazon.awssdk:s3:2.29.23")
+  implementation("org.json:json:20240303")
+  implementation("org.slf4j:jcl-over-slf4j:2.0.16")
+  testImplementation("org.junit.jupiter:junit-jupiter:5.10.0")
+}
+
+tasks.jar {
+  manifest {
+    attributes["Main-Class"] = "com.amazon.sampleapp.LambdaHandler"
+  }
+}
+
+tasks.register<Zip>("createLambdaZip") {
+  dependsOn("build")
+  from(tasks.compileJava.get())
+  from(tasks.processResources.get())
+  into("lib") {
+    from(configurations.runtimeClasspath.get())
+  }
+  archiveFileName.set("lambda-function.zip")
+  destinationDirectory.set(layout.buildDirectory.dir("distributions"))
+}

sample-apps/apigateway-lambda/src/main/java/com/amazon/sampleapp/LambdaHandler.java

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+package com.amazon.sampleapp;
+
+import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.RequestHandler;
+import java.io.IOException;
+import java.util.Map;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.Response;
+import org.json.JSONObject;
+import software.amazon.awssdk.services.s3.S3Client;
+import software.amazon.awssdk.services.s3.model.HeadBucketRequest;
+import software.amazon.awssdk.services.s3.model.S3Exception;
+
+public class LambdaHandler implements RequestHandler<Object, Map<String, Object>> {
+
+  private final OkHttpClient client = new OkHttpClient();
+  private final S3Client s3Client = S3Client.create();
+
+  @Override
+  public Map<String, Object> handleRequest(Object input, Context context) {
+    System.out.println("Executing LambdaHandler");
+
+    // https://docs.aws.amazon.com/lambda/latest/dg/configuration-envvars.html#configuration-envvars-runtime
+    // try and get the trace id from environment variable _X_AMZN_TRACE_ID. If it's not present
+    // there
+    // then try the system property.
+    String traceId =
+        System.getenv("_X_AMZN_TRACE_ID") != null
+            ? System.getenv("_X_AMZN_TRACE_ID")
+            : System.getProperty("com.amazonaws.xray.traceHeader");
+
+    System.out.println("Trace ID: " + traceId);
+
+    JSONObject responseBody = new JSONObject();
+    responseBody.put("traceId", traceId);
+
+    // Make a remote call using OkHttp
+    System.out.println("Making a remote call using OkHttp");
+    String url = "https://www.amazon.com";
+    Request request = new Request.Builder().url(url).build();
+
+    try (Response response = client.newCall(request).execute()) {
+      responseBody.put("httpRequest", "Request successful");
+    } catch (IOException e) {
+      context.getLogger().log("Error: " + e.getMessage());
+      responseBody.put("httpRequest", "Request failed");
+    }
+    System.out.println("Remote call done");
+
+    // Make a S3 HeadBucket call to check whether the bucket exists
+    System.out.println("Making a S3 HeadBucket call");
+    String bucketName = "SomeDummyBucket";
+    try {
+      HeadBucketRequest headBucketRequest = HeadBucketRequest.builder().bucket(bucketName).build();
+      s3Client.headBucket(headBucketRequest);
+      responseBody.put("s3Request", "Bucket exists and is accessible: " + bucketName);
+    } catch (S3Exception e) {
+      if (e.statusCode() == 403) {
+        responseBody.put("s3Request", "Access denied to bucket: " + bucketName);
+      } else if (e.statusCode() == 404) {
+        responseBody.put("s3Request", "Bucket does not exist: " + bucketName);
+      } else {
+        System.err.println("Error checking bucket: " + e.awsErrorDetails().errorMessage());
+        responseBody.put(
+            "s3Request", "Error checking bucket: " + e.awsErrorDetails().errorMessage());
+      }
+    }
+    System.out.println("S3 HeadBucket call done");
+
+    // return a response in the ApiGateway proxy format
+    return Map.of(
+        "isBase64Encoded",
+        false,
+        "statusCode",
+        200,
+        "body",
+        responseBody.toString(),
+        "headers",
+        Map.of("Content-Type", "application/json"));
+  }
+}

sample-apps/apigateway-lambda/terraform/main.tf

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+### Lambda function
+locals {
+  architecture = var.architecture == "x86_64" ? "amd64" : "arm64"
+}
+
+resource "aws_iam_role" "lambda_role" {
+  name               = "lambda_execution_role"
+  assume_role_policy = jsonencode({
+    Version = "2012-10-17",
+    Statement = [{
+      Action    = "sts:AssumeRole",
+      Effect    = "Allow",
+      Principal = { Service = "lambda.amazonaws.com" }
+    }]
+  })
+}
+
+resource "aws_iam_policy" "s3_access" {
+  name        = "S3ListBucketPolicy"
+  description = "Allow Lambda to check a given S3 bucket exists"
+  policy      = jsonencode({
+    Version = "2012-10-17",
+    Statement = [{
+      Effect   = "Allow",
+      Action   = ["s3:ListBucket"],
+      Resource = "*"
+    }]
+  })
+}
+
+resource "aws_iam_role_policy_attachment" "attach_execution_role_policy" {
+  role       = aws_iam_role.lambda_role.name
+  policy_arn = "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
+}
+
+resource "aws_iam_role_policy_attachment" "attach_s3_policy" {
+  role       = aws_iam_role.lambda_role.name
+  policy_arn = aws_iam_policy.s3_access.arn
+}
+
+resource "aws_iam_role_policy_attachment" "attach_xray_policy" {
+  role       = aws_iam_role.lambda_role.name
+  policy_arn = "arn:aws:iam::aws:policy/AWSXRayDaemonWriteAccess"
+}
+
+resource "aws_lambda_function" "sampleLambdaFunction" {
+  function_name    = var.function_name
+  runtime          = var.runtime
+  timeout          = 300
+  handler          = "com.amazon.sampleapp.LambdaHandler::handleRequest"
+  role             = aws_iam_role.lambda_role.arn
+  filename         = "${path.module}/../build/distributions/lambda-function.zip"
+  source_code_hash = filebase64sha256("${path.module}/../build/distributions/lambda-function.zip")
+  architectures    = [var.architecture]
+  memory_size      = 512
+  tracing_config {
+    mode = var.lambda_tracing_mode
+  }
+  layers = var.adot_layer_arn != null && var.adot_layer_arn != "" ? [var.adot_layer_arn] : []
+  environment {
+    variables = var.adot_layer_arn != null && var.adot_layer_arn != "" ? {
+      AWS_LAMBDA_EXEC_WRAPPER = "/opt/otel-instrument"
+    } : {}
+  }
+}
+
+### API Gateway proxy to Lambda function
+resource "aws_api_gateway_rest_api" "apigw_lambda_api" {
+  name = var.api_gateway_name
+}
+
+resource "aws_api_gateway_resource" "apigw_lambda_resource" {
+  rest_api_id = aws_api_gateway_rest_api.apigw_lambda_api.id
+  parent_id   = aws_api_gateway_rest_api.apigw_lambda_api.root_resource_id
+  path_part   = "lambda"
+}
+
+resource "aws_api_gateway_method" "apigw_lambda_method" {
+  rest_api_id   = aws_api_gateway_rest_api.apigw_lambda_api.id
+  resource_id   = aws_api_gateway_resource.apigw_lambda_resource.id
+  http_method   = "ANY"
+  authorization = "NONE"
+}
+
+resource "aws_api_gateway_integration" "apigw_lambda_integration" {
+  rest_api_id = aws_api_gateway_rest_api.apigw_lambda_api.id
+  resource_id = aws_api_gateway_resource.apigw_lambda_resource.id
+  http_method = aws_api_gateway_method.apigw_lambda_method.http_method
+  integration_http_method = "POST"
+  type                    = "AWS_PROXY"
+  uri                     = aws_lambda_function.sampleLambdaFunction.invoke_arn
+}
+
+resource "aws_api_gateway_deployment" "apigw_lambda_deployment" {
+  depends_on = [
+    aws_api_gateway_integration.apigw_lambda_integration
+  ]
+  rest_api_id = aws_api_gateway_rest_api.apigw_lambda_api.id
+}
+
+resource "aws_api_gateway_stage" "test" {
+  stage_name           = "default"
+  rest_api_id          = aws_api_gateway_rest_api.apigw_lambda_api.id
+  deployment_id        = aws_api_gateway_deployment.apigw_lambda_deployment.id
+  xray_tracing_enabled = var.apigw_tracing_enabled
+}
+
+resource "aws_lambda_permission" "apigw_lambda_invoke" {
+  statement_id  = "AllowAPIGatewayInvoke"
+  action        = "lambda:InvokeFunction"
+  function_name = aws_lambda_function.sampleLambdaFunction.function_name
+  principal     = "apigateway.amazonaws.com"
+  source_arn    = "${aws_api_gateway_rest_api.apigw_lambda_api.execution_arn}/*/*"
+}
+
+# Output the API Gateway URL
+output "invoke_url" {
+  value = "${aws_api_gateway_stage.test.invoke_url}/lambda"
+}

sample-apps/apigateway-lambda/terraform/variables.tf

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+## Lambda function related configurations
+variable "function_name" {
+  type        = string
+  description = "Name of sample app function"
+  default     = "aws-opentelemetry-distro-java"
+}
+
+variable "architecture" {
+  type        = string
+  description = "Lambda function architecture, either arm64 or x86_64"
+  default     = "x86_64"
+}
+
+variable "runtime" {
+  type        = string
+  description = "Java runtime version used for Lambda Function"
+  default     = "java17"
+}
+
+variable "lambda_tracing_mode" {
+  type        = string
+  description = "Lambda function tracing mode"
+  default     = "Active"
+}
+
+variable "adot_layer_arn" {
+  type        = string
+  description = "ARN of the ADOT JAVA layer"
+  default     = null
+}
+
+## API Gateway related configurations
+variable "api_gateway_name" {
+  type        = string
+  description = "Name of API gateway to create"
+  default     = "aws-opentelemetry-distro-java"
+}
+
+variable "apigw_tracing_enabled" {
+  type        = string
+  description = "API Gateway REST API tracing enabled or not"
+  default     = "true"
+}

settings.gradle.kts

@@ -51,6 +51,7 @@ include(":smoke-tests:spring-boot")
 include(":sample-apps:springboot")
 include(":sample-apps:spark")
 include(":sample-apps:spark-awssdkv1")
+include(":sample-apps:apigateway-lambda")
 
 // Used for contract tests
 include("appsignals-tests:images:mock-collector")