Tech-Notes

Load Balancer

simple load balancing and routing are your primary needs, an AWS Load Balancer with an Ingress Controller is typically sufficient.

S3 Bucket

S3 (Simple Storage Service) is an object storage service

Advantages: designed for scalability, data availability, security, and performance.

• Each object/Bucket has a key (unique identifier), metadata, and data (file content). Global Unique Name: Each bucket name must be unique across all AWS accounts globally.

aws.accessKeyId=YOUR_ACCESS_KEY
aws.secretKey=YOUR_SECRET_KEY
aws.region=YOUR_REGION

API Gateway

API-specific features like rate limiting, access control, and request transformations, API Gateway can add value, especially for public APIs.

StreamHandler.java

public class StreamHandler implements RequestStreamHandler{
    public void handleRequest(InputStream inputStream, OutputStream outputStream, Context context) throws IOException {
        int letter;
        while((letter = inputStream.read()) != -1)
        {	
        	System.out.println(letter);
            outputStream.write(Character.toUpperCase(letter));
        }
    }
}

---

ApiGatewayProxy.java

public class ApiGatewayProxy implements RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> {
	public APIGatewayProxyResponseEvent handleRequest(APIGatewayProxyRequestEvent requestEvent, Context context) {
		APIGatewayProxyResponseEvent responseEvent = new APIGatewayProxyResponseEvent();
		try {
			LambdaLogger logger = context.getLogger();
			logger.log("requestEventString:" + requestEvent.toString());
			logger.log("query string param:" + requestEvent.getQueryStringParameters());
			logger.log("headers:" + requestEvent.getHeaders());
			// fetching the value send in the request body
			String message = requestEvent.getBody();
			// Request request = gson.fromJson(message, Request.class);
			logger.log("message body:" + message);
			// setting up the response message
			responseEvent.setBody("Hello from Lambda!");
			responseEvent.setStatusCode(200);

			return responseEvent;

		} catch (Exception ex) {
			responseEvent.setBody("Invalid Response");
			responseEvent.setStatusCode(500);
			return responseEvent;
		}
	}
}

---

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>sample-lamda</groupId>
	<artifactId>samplLam</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<properties>
		<maven.compiler.source>1.8</maven.compiler.source>
		<maven.compiler.target>1.8</maven.compiler.target>
		<aws.java.sdk.version>2.14.11</aws.java.sdk.version>
	</properties>
	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>software.amazon.awssdk</groupId>
				<artifactId>bom</artifactId>
				<version>${aws.java.sdk.version}</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>
	<dependencies>
		<!-- https://mvnrepository.com/artifact/com.amazonaws/aws-lambda-java-events -->
		<dependency>
			<groupId>com.amazonaws</groupId>
			<artifactId>aws-lambda-java-events</artifactId>
			<version>3.2.0</version>
		</dependency>
		<dependency>
			<groupId>com.amazonaws</groupId>
			<artifactId>aws-lambda-java-core</artifactId>
			<version>1.2.0</version>
		</dependency>
	</dependencies>
	<build>
		<plugins>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<configuration>
					<source>${maven.compiler.source}</source>
					<target>${maven.compiler.target}</target>
				</configuration>
			</plugin>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-shade-plugin</artifactId>
				<version>3.2.4</version>
				<executions>
					<execution>
						<phase>package</phase>
						<goals>
							<goal>shade</goal>
						</goals>
					</execution>
				</executions>
			</plugin>
		</plugins>
	</build>
</project>

###API GATEWAY configuration
create api, point the lamda-> Deploy api->
Usage plans need to give api key