Lambda Networking (VPC) - AWS Serverless

1. Introduction

Amazon Web Services (AWS) Lambda is a serverless compute service that enables you to run code without provisioning or managing servers. When using Lambda in conjunction with a Virtual Private Cloud (VPC), you can securely connect your Lambda functions to other resources within your VPC.

2. Key Concepts

• VPC (Virtual Private Cloud): A virtual network dedicated to your AWS account.
• Subnets: Segments within a VPC that define a range of IP addresses.
• Security Groups: Virtual firewalls that control inbound and outbound traffic.
• NAT Gateway: Allows outbound internet access for resources in a private subnet.

3. Setting Up VPC for Lambda

To configure a Lambda function to run within a VPC, follow these steps:

1. Log in to the AWS Management Console.
2. Navigate to the VPC Dashboard and create a new VPC.
3. Create subnets within your VPC, ensuring you have at least one public and one private subnet.
4. Create a NAT Gateway in the public subnet.
5. Create security groups with the necessary inbound/outbound rules.
6. Go to the Lambda console and create a new Lambda function or select an existing one.
7. In the function configuration, under "VPC", select the VPC and the subnets you created.
8. Assign the security group you created to the Lambda function.

Lambda Function Example

const AWS = require('aws-sdk');
const ec2 = new AWS.EC2();

exports.handler = async (event) => {
    const params = {
        // Your parameters here
    };
    const data = await ec2.describeInstances(params).promise();
    return data;
};

4. Best Practices

• Use separate VPCs for different environments (development, testing, production).
• Minimize the number of subnets to simplify management.
• Regularly review and update security group rules.
• Monitor Lambda function performance and VPC flow logs for troubleshooting.

5. FAQ