lambda handler java 11
Build the project
install maven if not already installed with command sudo apt install maven
run the below command to create jar file
mvn clean package
it will create target directory which will have the jar file with name like my-lambda-function-1.0-SNAPSHOT.jar
Open the AWS Management Console: Go to the AWS Management Console.
Navigate to AWS Lambda: Search for "Lambda" in the services menu and select it.
Create a New Function: Click on the "Create function" button.
Configure the Function:
Function name: Enter a unique name for your function. Runtime: Select "Java 11" (or the appropriate version you're using). Role: Choose "Create a new role with basic Lambda permissions" or "Use an existing role" if you have a predefined role. Click "Create function".
Upload the .jar File: In the function's configuration page, scroll down to the "Function code" section.
Code entry type: Choose "Upload a .zip or .jar file". Runtime: Ensure it's set to "Java 11" (or your version). Handler: Set the handler to the appropriate method in your code. For example:
com.example.LambdaFunctionHandler::handleRequest
Upload: Click "Upload" and select your .jar file.
Add Environment Variables: Scroll down to the "Environment variables" section and add the following variables like database credentials as used in the code MYSQL_URL MYSQL_USER MYSQL_PASSWORD REST_API_URL
IAM Role Permissions: Ensure your Lambda function's IAM role has the necessary permissions to interact with Redis, MySQL, and make HTTP requests. Attach the following managed policies: AmazonRDSFullAccess AWSLambdaBasicExecutionRole
Modify Permissions: If necessary, customize the IAM policy attached to your role to include any specific permissions required by your function.
Configure SnapStart
Enable SnapStart: In the Lambda function's configuration page, go to the "SnapStart" section. Enable SnapStart for your function. This will allow AWS to take a snapshot of your function's state after initialization, leading to faster cold starts.
Test the Function
Create a Test Event: Go to the "Test" tab. Click "Configure test event". Choose "Create new test event". Enter a name for the test event and provide a sample JSON payload if needed. Click "Create".
Run the Test: Click "Test" to invoke your Lambda function. Review the results in the console to ensure the function behaves as expected.