Logging in AWS Lambda with slf4j

I am using a lambda function and writing it in Java. I was looking up logging for Lambda functions when I read the docs and they support log4j – http://docs.aws.amazon.com/lambda/latest/dg/java-logging.html#java-wt-logging-using-log4j.

I was wondering if we could use logging using the Slf4j annotation as well since Slf4j is only a binding annotation. Has anybody tried using Slf4j before with lambda?

Answer

Yes, you can. Just add the following dependencies to your project:

    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>jcl-over-slf4j</artifactId>
        <version>1.7.25</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>1.7.25</version>
    </dependency>
    <dependency>
        <groupId>com.amazonaws</groupId>
        <artifactId>aws-lambda-java-log4j</artifactId>
        <version>1.0.0</version>
    </dependency>

and create correct log4j.properties in /src/main/resources/ of your project, e.g.

log = .
log4j.rootLogger = DEBUG, LAMBDA

# Define the LAMBDA appender
log4j.appender.LAMBDA=com.amazonaws.services.lambda.runtime.log4j.LambdaAppender
log4j.appender.LAMBDA.layout=org.apache.log4j.PatternLayout
log4j.appender.LAMBDA.layout.conversionPattern=%d{yyyy-MM-dd HH:mm:ss} <%X{AWSRequestId}> %-5p %c{1}:%m%n