How to link AWS Lambda function to Amazon CloudWatch

Question

I have set up a Lambda function which will process a file as soon as it is uploaded to an S3 bucket. I need a way to see the output of console.log when I upload a file, but I can't figure out how to link my Lambda function to CloudWatch.

By looking at the context object i figured out my log group is /aws/lambda/wavToMp3 and the log stream is 2018/05/23/[$LATEST]hex_code_redacted. So I created that group and stream in CloudWatch, yet nothing is being logged to it.

I don’t know what the error is.

Answer 1

In order to create Log Group and Log Stream Lambda execution role needs to have set of permissions enabled.

{
    "Statement": [
        {
            "Action": [
                "logs:CreateLogGroup",
                 "logs:CreateLogStream",
                 "logs:PutLogEvents"
            ],
            "Effect": "Allow",
            "Resource": "arn:aws:logs:*:*:*"
        }
    ]
} 

Once the necessary permissions are set it should work properly. You can check out AWS Documentation on Lambda function for more details.