AWS Lambda Local Runner (JAVA)

This is a AWS Lambda JAVA simulator that allows running and debugging Lambda functions authored in JAVA locally. You can add this tool to your Lambda project as a provided dependency and enjoy testing locally your Lambda functions in JAVA.

Installation

Add this custom repository to your pom.xml

<repositories>
    <repository>
        <id>cagatay-gurturk</id>
        <url>http://maven.cagataygurturk.com/releases</url>
    </repository>
</repositories>

And add the dependency as a provided dependency:

    <dependency>
        <groupId>com.cagataygurturk</groupId>
        <artifactId>aws-lambda-local-runner</artifactId>
        <version>0.0.1</version>
        <!--
        Scope: provided makes this dependency to be excluded from deployment package
        So it extremely reduces JAR package size
        -->
        <scope>provided</scope>  
    </dependency>

And as a last step add exec-maven plugin to your build plugins:

    <build>
        <plugins>
        ....
                <plugin>
                    <groupId>org.codehaus.mojo</groupId>
                    <artifactId>exec-maven-plugin</artifactId>
                    <version>1.2.1</version>
                    <configuration>
                        <mainClass>com.cagataygurturk.lambda.LocalRunner</mainClass>
                        <arguments>
                            <argument>YOUR_HANDLER_FUNCTION</argument>
                        </arguments>
                    </configuration>
                </plugin>
        .....
        </plugins>
    <build>

Note: With provided option, you ensure that this JAR and its dependencies are not included in the JAR file of your application.

Usage

Your handler function should implement com.amazonaws.services.lambda.runtime.RequestHandler<I, O> interface as it is shown in AWS Lambda documentation.

In case of your handler function implements a public String getExampleEvent() method that returns a valid JSON Script, the return value of this method is injected to your Lambda function as an event. An example implementation would be:

public String getExampleEvent() {
    return "{\"firstName\": \"John Doe\"}";
}

Once you finish the configuration, in the root folder of your application fire this command:

mvn compile exec:java

Your handler is invoked and the result is printed to the screen.

See aws-lambda-java-boilerplate project for a real implementation.

Contribution

Feel free to create an issue and send a pull request.

cagataygurturk/aws-lambda-local-runner

AWS Lambda Local Runner (JAVA)

Installation

Usage

Contribution