Aws serverless

--- name: aws-serverless description: Specialized skill for building production-ready serverless applications on AWS. Covers Lambda functions, API Gateway, DynamoDB, SQS/SNS event-driven patterns, SAM/CDK deployment, and cold start optimization. risk: unknown source: vibeship-spawner-skills (Apache 2.0) date_added: 2026-02-27 --- # AWS Serverless Specialized skill for building production-ready serverless applications on AWS. Covers Lambda functions, API Gateway, DynamoDB, SQS/SNS event-driven patterns, SAM/CDK deployment, and cold start optimization. ## Principles - Right-size memory and timeout (measure before optimizing) - Minimize cold starts for latency-sensitive workloads - Use SnapStart for Java/.NET functions - Prefer HTTP API over REST API for simple use cases - Design for failure with DLQs and retries - Keep deployment packages small - Use environment variables for configuration - Implement structured logging with correlation IDs ## Patterns ### Lambda Handler Pattern Proper Lambda function structure with error handling When to use: Any Lambda function implementation,API handlers, event processors, scheduled tasks ``javascript // Node.js Lambda Handler // handler.js // Initialize outside handler (reused across invocations) const { DynamoDBClient } = require('@aws-sdk/client-dynamodb'); const { DynamoDBDocumentClient, GetCommand } = require('@aws-sdk/lib-dynamodb'); const client = new DynamoDBClient({}); const docClient = DynamoDBDocumentClient.from(client); // Handler function exports.handler = async (event, context) => { // Optional: Don't wait for event loop to clear (Node.js) context.callbackWaitsForEmptyEventLoop = false; try { // Parse input based on event source const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body; // Business logic const result = await processRequest(body); // Return API Gateway compatible response return { statusCode: 200, headers: { 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*' }, body: JSON.stringify(result) }; } catch (error) { console.error('Error:', JSON.stringify({ error: error.message, stack: error.stack, requestId: context.awsRequestId })); return { statusCode: error.statusCode || 500, headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ error: error.message || 'Internal server error' }) }; } }; async function processRequest(data) { // Your business logic here const result = await docClient.send(new GetCommand({ TableName: process.env.TABLE_NAME, Key: { id: data.id } })); return result.Item; } ` `python # Python Lambda Handler # handler.py import json import os import logging import boto3 from botocore.exceptions import ClientError # Initialize outside handler (reused across invocations) logger = logging.getLogger() logger.setLevel(logging.INFO) dynamodb = boto3.resource('dynamodb') table = dynamodb.Table(os.environ['TABLE_NAME']) def handler(event, context): try: # Parse input body = json.loads(event.get('body', '{}')) if isinstance(event.get('body'), str) else event.get('body', {}) # Business logic result = process_request(body) return { 'statusCode': 200, 'headers': { 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*' }, 'body': json.dumps(result) } except ClientError as e: logger.error(f"DynamoDB error: {e.response['Error']['Message']}") return error_response(500, 'Database error') except json.JSONDecodeError: return error_response(400, 'Invalid JSON') except Exception as e: logger.error(f"Unexpected error: {str(e)}", exc_info=True) return error_response(500, 'Internal server error') def process_request(data): response = table.get_item(Key={'id': data['id']}) return response.get('Item') def error_response(status_code, message): return { 'statusCode': status_code, 'headers': {'Content-Type': 'application/json'}, 'body': json.dumps({'error': message}) } ` ### Best_practices - Initialize clients outside handler (reused across warm invocations) - Always return proper API Gateway response format - Log with structured JSON for CloudWatch Insights - Include request ID in error logs for tracing ### API Gateway Integration Pattern REST API and HTTP API integration with Lambda **When to use**: Building REST APIs backed by Lambda,Need HTTP endpoints for functions ``yaml # template.yaml (SAM) AWSTemplateFormatVersion: '2010-09-09' Transform: AWS::Serverless-2016-10-31 Globals: Function: Runtime: nodejs20.x Timeout: 30 MemorySize: 256 Environment: Variables: TABLE_NAME: !Ref ItemsTable Resources: # HTTP API (r