awslambdaupdate

AWS Lambda Function Update Java example

This folder contains a Java application example that handles Lambda functions on AWS (Amazon Web Services).

Update an AWS Lambda function.

Requirements

• You must have an Amazon Web Services (AWS) account.

• The code was written for:

  • Java 8
  • Apache Maven 3
  • AWS SDK for Java (SDK V2)

Using the code

• Configure your AWS access keys.

  Important: For security, it is strongly recommend that you use IAM users instead of the root account for AWS access.

  When you initialize a new service client without supplying any arguments, the AWS SDK for Java attempts to find AWS credentials by using the default credential provider chain.

  Setting your credentials for use by the AWS SDK for Java can be done in a number of ways, but here are the recommended approaches:

  • The default credential profiles file.

    Set credentials in the AWS credentials profile file on your local system, located at:

    • ~/.aws/credentials on Linux, macOS, or Unix.

    • C:\Users\USERNAME\.aws\credentials on Windows.

    This file should contain lines in the following format:

    [default]
    aws_access_key_id = <YOUR_ACCESS_KEY_ID>
    aws_secret_access_key = <YOUR_SECRET_ACCESS_KEY>

    Replace the values of <YOUR_ACCESS_KEY_ID> and <YOUR_SECRET_ACCESS_KEY> by your AWS credentials.

  • Environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY.

    Set the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables.

    To set these variables on Linux, macOS, or Unix, use export:

    export AWS_ACCESS_KEY_ID=<YOUR_ACCESS_KEY_ID>
    export AWS_SECRET_ACCESS_KEY=<YOUR_SECRET_ACCESS_KEY>

    To set these variables on Windows, use set:

    set AWS_ACCESS_KEY_ID=<YOUR_ACCESS_KEY_ID>
    set AWS_SECRET_ACCESS_KEY=<YOUR_SECRET_ACCESS_KEY>

    Replace the values of <YOUR_ACCESS_KEY_ID> and <YOUR_SECRET_ACCESS_KEY> by your AWS credentials.

• The AWS Lambda function to update must already exist.

  You can use the AWS Lambda Function Hello World JSON Java example: awslambdahellojson.

• You need a JAR or ZIP file where the code of the Lambda function is located.

  You can use the code obtained from the AWS Lambda Function Hello World JSON Java example: awslambdahellojson.

• You can select the AWS region of the Lambda function changing the value of REGION variable in the code.

• You have to create an AWS role that has Lambda permissions.

• Run the code.

  You must provide 4 parameter, replace the values of:

  • <FUNCTION_NAME> by Lambda function name.
  • <FUNCTION_FILE> by path to the JAR or ZIP file where the code of the Lambda function is located.
  • <FUNCTION_ROLE> by role ARN that has Lambda permissions.
  • <FUNCTION_HANDLER> by fully qualifed method name (Ex: example.Handler::handleRequest).

  Run application:

  java -jar awslambdaupdate.jar <FUNCTION_NAME> <FUNCTION_FILE> <FUNCTION_ROLE> <FUNCTION_HANDLER>

  You must use as a function role the ARN.

  Ex.: arn:aws:iam::123456789012:role/service-role/lambda-basic-execution

• Test the application.

  The Lambda function is updated and you should see the messages:

  • Updating Lambda function ...
  • Updated