Follow these steps to deploy and invoke the Lambda. You may follow Chapter 1, Getting Started with Serverless Computing on AWS and use CloudFormation for Lambda provisioning:

1. Run mvn clean package from inside the Lambda project root folder to create the Uber JAR
2. Upload the Uber JAR to S3:

aws s3 cp 
    target/lambda-invoke-sqs-event-0.0.1-SNAPSHOT.jar 
    s3://serverless-cookbook/lambda-invoke-sqs-event-0.0.1-SNAPSHOT.jar 
    --profile admin

3. Create a role for the Lambda with an appropriate trust relationship definition:

aws iam create-role 
    --role-name lambda-invoke-sqs-event-role 
    --assume-role-policy-document file://iam-role-trust-relationship.txt 
    --profile admin

The trust document, iam-role-trust-relationship.txt, is defined as follows:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "lambda.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}

4. Create a policy for basic logging permissions and attach it to the role
5. Create a policy for required SQS permissions and attach it to the role

The policy document with required SQS permissions is shown here:

{
   "Version":"2012-10-17",
   "Statement":[
      {
         "Effect":"Allow",
         "Action":[
            "sqs:GetQueueAttributes",
            "sqs:ReceiveMessage",
            "sqs:DeleteMessage",
            "sqs:SendMessage",
            "sqs:SendMessageBatch"
         ],
         "Resource":[
            "arn:aws:sqs:*:*:*"
         ]
      }
   ]
}

A Lambda configured to be invoked by an SQS even source should have the following permissions:

• sqs:GetQueueAttributes
• sqs:ReceiveMessage
• sqs:DeleteMessage

 I have also added the send message permissions, as we will be forwarding the messages to another queue

6. Create the Lambda function, as shown here:

aws lambda create-function 
    --function-name lambda-invoke-sqs-event 
    --runtime java8 
    --role arn:aws:iam::855923912133:role/lambda-invoke-sqs-event-role 
    --handler tech.heartin.books.serverlesscookbook.LambdaSqsEventHandler::handleRequest 
    --code S3Bucket=serverless-cookbook,S3Key=lambda-invoke-sqs-event-0.0.1-SNAPSHOT.jar 
    --environment Variables={SPC_OUTPUT_QUEUE_URL='https://queue.amazonaws.com/855923912133/my-output-queue'} 
    --timeout 15 
    --memory-size 512 
    --region us-east-1 
    --profile admin

7. Configure an SQS event source for the Lambda:

aws lambda create-event-source-mapping 
    --event-source-arn arn:aws:sqs:us-east-1:855923912133:my-input-queue 
    --function-name lambda-invoke-sqs-event 
    --batch-size 4 
    --profile admin

The batch-size parameter specifies the maximum number of messages to be retrieved from the queue together