13 Lambda Vpc

title: Lambda VPC Configuration for Serverless APIs weight: 23 date: 2026-06-28 lastmod: 2026-06-28 description: Configure AWS Lambda in a VPC for private resource access including VPC configuration, NAT Gateway requirements, security groups, and cold start implications. tags: [api-development, serverless]

Lambda VPC configuration enables access to private resources like RDS databases and ElastiCache clusters, requiring VPC subnet configuration, security group rules, NAT Gateway for internet access, and understanding cold start latency impact.

```python
import json
import pymysql
import os

DB_HOST = os.environ["DB_HOST"]
DB_USER = os.environ["DB_USER"]
DB_PASS = os.environ["DB_PASS"]
DB_NAME = os.environ["DB_NAME"]

connection = None

def get_connection():
    global connection
    if connection is None:
        connection = pymysql.connect(
            host=DB_HOST,
            user=DB_USER,
            password=DB_PASS,
            database=DB_NAME,
            connect_timeout=5
        )
    return connection

def lambda_handler(event, context):
    conn = get_connection()
    with conn.cursor() as cursor:
        cursor.execute("SELECT id, name, email FROM users LIMIT 10")
        users = [{"id": row[0], "name": row[1], "email": row[2]} for row in cursor.fetchall()]
    return {"statusCode": 200, "body": json.dumps({"users": users})}

What's Next

Now learn about Serverless Framework in Building Serverless APIs.