In this blog, we’ll explore how to create a VPC and subnets using AWS CDK in Python. Whether you’re new to AWS CDK or cloud networking, this post will help you understand how to set up a VPC with public and private subnets, configure CIDR blocks correctly, and understand how AWS handles availability zones.
You can also watch the complete hands-on tutorial on my YouTube channel here:
Understanding the VPC Basics:
A Virtual Private Cloud (VPC) is your private network in AWS. It allows you to control your IP address range, create subnets, and configure route tables and gateways.
When you create a VPC using AWS CDK, you define the following:
-
CIDR Block (e.g.,
10.0.0.0/28) -
Subnets (public/private/isolated)
-
Availability Zones
-
NAT Gateway (if private subnets need internet access)
Setting Up the VPC Using CDK:
Here’s how you can define your VPC in CDK:
from aws_cdk import (
# Duration,
Stack,
aws_ec2 as ec2,
)
from constructs import Construct
import os
class AwsCdkVpcStack(Stack):
def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
super().__init__(scope, construct_id, **kwargs)
# The code that defines your stack goes here
self.vpc = ec2.Vpc(
self,
id=f"{os.getenv('AWS_ENV')}_{os.getenv('VPC_NAME')}",
vpc_name=os.getenv('VPC_NAME'),
cidr=os.getenv('CIDR_BLOCK'),
max_azs=2,
create_internet_gateway=True,
nat_gateways=0,
subnet_configuration=[
ec2.SubnetConfiguration(
name=f"PublicSubnet_{os.getenv('AWS_ENV')}_{os.getenv('VPC_NAME')}_{self.region}",
subnet_type=ec2.SubnetType.PUBLIC,
cidr_mask=28,
map_public_ip_on_launch=True
),
ec2.SubnetConfiguration(
name=f"PrivateSubnet_{os.getenv('AWS_ENV')}_{os.getenv('VPC_NAME')}_{self.region}",
subnet_type=ec2.SubnetType.PRIVATE_WITH_EGRESS,
cidr_mask=28
),
ec2.SubnetConfiguration(
name=f"IsolatedSubnet_{os.getenv('AWS_ENV')}_{os.getenv('VPC_NAME')}_{self.region}",
subnet_type=ec2.SubnetType.PRIVATE_ISOLATED,
cidr_mask=28
),
]
)
| Command | Purpose |
|---|---|
cdk synth |
Synthesizes your CDK code into a CloudFormation template |
cdk bootstrap |
Prepares your AWS environment for CDK deployments |
cdk deploy |
Deploys your stack(s) to AWS |
GITHUB Link: https://github.com/jksnu/aws_vpc_cdk.git
