AWS SQS with Lambda Terraform Template

# Terraform configuration for AWS SQS with Lambda trigger

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 4.0"
    }
  }
}

provider "aws" {
  region = "us-east-1" # Change to your preferred region
}

# Create SQS queue
resource "aws_sqs_queue" "example_queue" {
  name                      = "example-queue"
  delay_seconds             = 0
  max_message_size          = 262144 # 256 KiB
  message_retention_seconds = 345600 # 4 days
  receive_wait_time_seconds = 10     # Long polling wait time
  visibility_timeout_seconds = 30    # Should be >= Lambda timeout

  tags = {
    Environment = "production"
  }
}

# IAM role for Lambda execution
resource "aws_iam_role" "lambda_exec_role" {
  name = "lambda_exec_role"

  assume_role_policy = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Action = "sts:AssumeRole"
        Effect = "Allow"
        Principal = {
          Service = "lambda.amazonaws.com"
        }
      }
    ]
  })
}

# IAM policy for Lambda to access SQS
resource "aws_iam_policy" "lambda_sqs_policy" {
  name        = "lambda_sqs_policy"
  description = "Policy for Lambda to read from SQS"

  policy = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Effect = "Allow"
        Action = [
          "sqs:ReceiveMessage",
          "sqs:DeleteMessage",
          "sqs:GetQueueAttributes"
        ]
        Resource = aws_sqs_queue.example_queue.arn
      },
      {
        Effect = "Allow"
        Action = [
          "logs:CreateLogGroup",
          "logs:CreateLogStream",
          "logs:PutLogEvents"
        ]
        Resource = "arn:aws:logs:*:*:*"
      }
    ]
  })
}

# Attach policy to Lambda role
resource "aws_iam_role_policy_attachment" "lambda_sqs_attachment" {
  role       = aws_iam_role.lambda_exec_role.name
  policy_arn = aws_iam_policy.lambda_sqs_policy.arn
}

# Lambda function
resource "aws_lambda_function" "sqs_processor" {
  filename      = "lambda_function.zip" # Replace with your Lambda package
  function_name = "sqs_processor"
  role          = aws_iam_role.lambda_exec_role.arn
  handler       = "index.handler"
  runtime       = "nodejs14.x" # Change to your preferred runtime

  source_code_hash = filebase64sha256("lambda_function.zip")

  environment {
    variables = {
      QUEUE_URL = aws_sqs_queue.example_queue.url
    }
  }
}

# Lambda event source mapping
resource "aws_lambda_event_source_mapping" "sqs_trigger" {
  event_source_arn = aws_sqs_queue.example_queue.arn
  function_name    = aws_lambda_function.sqs_processor.arn
  batch_size       = 10 # Number of messages to process at once
}

// Example Lambda function to process SQS messages
exports.handler = async (event) => {
    console.log('Received event:', JSON.stringify(event, null, 2));
    
    for (const record of event.Records) {
        try {
            const message = JSON.parse(record.body);
            console.log('Processing message:', message);
            
            // Your message processing logic here
            // Example: Send to another service, transform data, etc.
            
            console.log('Successfully processed message ID:', record.messageId);
        } catch (error) {
            console.error('Error processing message:', error);
            // You might want to implement dead-letter queue handling here
            throw error; // This will make Lambda retry the batch
        }
    }
    
    return {
        statusCode: 200,
        body: JSON.stringify('Messages processed successfully')
    };
};