Serverless Framework - VPC - Static IP

index.js

/* global fetch */
const serverless = require("serverless-http");
const express = require("express");
const app = express();

app.use(async (req, res, next) => {
  const response = await fetch("https://api.ipify.org");
  const ip = await response.text();
  res.locals.ip_addr = ip;
  next();
});

app.get("/", (req, res, next) => {
  return res.status(200).json({
    message: "Hello from root!",
    ip: res.locals.ip_addr,
  });
});

app.get("/path", (req, res, next) => {
  return res.status(200).json({
    message: "Hello from path!",
    ip: res.locals.ip_addr,
  });
});

app.use((req, res, next) => {
  return res.status(404).json({
    error: "Not Found",
  });
});

module.exports.handler = serverless(app);

serverless.yml

service: vpc-test
frameworkVersion: "3"

provider:
  name: aws
  runtime: nodejs18.x

functions:
  api:
    handler: index.handler
    events:
      - httpApi: "*"
    vpc:
      securityGroupIds:
        - !Ref MyLambdaSecurityGroup
      subnetIds:
        - !Ref PublicSubnet
        - !Ref PrivateSubnet

custom:
  customDomain:
    domainName: "test.domain.com"
    basePath: v1
    endpointType: regional
    apiType: http
    createRoute53Record: true

resources:
  Resources:
    VPC:
      Type: AWS::EC2::VPC
      Properties:
        CidrBlock: 10.0.0.0/16

    # Public subnet definition
    PublicSubnet:
      Type: AWS::EC2::Subnet
      Properties:
        VpcId: !Ref VPC
        CidrBlock: 10.0.1.0/24
        AvailabilityZone: us-east-1a

    # Private subnet definition
    PrivateSubnet:
      Type: AWS::EC2::Subnet
      Properties:
        VpcId: !Ref VPC
        CidrBlock: 10.0.2.0/24
        AvailabilityZone: us-east-1a

    # Internet Gateway definition
    InternetGateway:
      Type: AWS::EC2::InternetGateway
      Properties:

    # VPC Gateway Attachment
    VPCGatewayAttachment:
      Type: AWS::EC2::VPCGatewayAttachment
      Properties:
        VpcId: !Ref VPC
        InternetGatewayId: !Ref InternetGateway

    # Security Group definition for Lambda function
    MyLambdaSecurityGroup:
      Type: AWS::EC2::SecurityGroup
      Properties:
        GroupName: proxy-sg-${sls:stage}
        GroupDescription: Allow http traffic through
        VpcId: !Ref VPC
        SecurityGroupIngress:
          - FromPort: 80
            ToPort: 80
            IpProtocol: tcp
            CidrIp: 0.0.0.0/0
        SecurityGroupEgress:
          - FromPort: 80
            ToPort: 80
            IpProtocol: tcp
            CidrIp: 0.0.0.0/0

    PublicRouteTable:
      Type: AWS::EC2::RouteTable
      Properties:
        VpcId: !Ref VPC

    PublicRoute:
      Type: AWS::EC2::Route
      DependsOn: VPCGatewayAttachment
      Properties:
        RouteTableId: !Ref PublicRouteTable
        DestinationCidrBlock: 0.0.0.0/0
        GatewayId: !Ref InternetGateway

    # NAT Gateway definition with Elastic IP allocation
    NatGateway:
      Type: AWS::EC2::NatGateway
      Properties:
        SubnetId: !Ref PublicSubnet
        AllocationId: !GetAtt ElasticIp.AllocationId

    # Elastic IP definition
    ElasticIp:
      Type: AWS::EC2::EIP
      Properties:

  Outputs:
    NatGatewayPublicIp:
      Value: !GetAtt ElasticIp.PublicIp

plugins:
  - serverless-domain-manager