Easily build network infrastructure and EC2 with AWS CDK Python

If you want to build AWS infrastructure and EC2 as a set quickly and easily, AWS CDK is a very useful tool. This time, I will show you how to use AWS CDK Python.

Premise

Work environment

• OS: CentOS 7.7.1908
• Python 3.7.1
• NodeJs v13.0.1 --aws config: configured

AWS environment

--aws keypair: Created. Name it'testkey'.

Constitution

--VPC is cut at / 21. 10.0.0.0/21 --Subnet: 1 Public (/24), 1 Private (/24) --SecurityGroup: Open port 22 inbound to use SSH for EC2

procedure

Install CDK

# npm install -g aws-cdk

Create test project tescdk

# mkdir testcdk
# cd testcdk
# cdk init --language python
Applying project template app for python
Initializing a new git repository...
Executing Creating virtualenv...
# Welcome to your CDK Python project!
This is a blank project for Python development with CDK.
The `cdk.json` file tells the CDK Toolkit how to execute your app.
(abridgement)
## Useful commands
 * `cdk ls`          list all stacks in the app
 * `cdk synth`       emits the synthesized CloudFormation template
 * `cdk deploy`      deploy this stack to your default AWS account/region
 * `cdk diff`        compare deployed stack with current state
 * `cdk docs`        open CDK documentation
Enjoy!

Check directory and file structure

# tree
.
|-- .env
|-- README.md
|-- app.py
|-- cdk.json
|-- requirements.txt
|-- setup.py
|-- source.bat
`-- testcdk
    |-- __init__.py
    `-- testcdk_stack.py

Enable Python virtual environment

# source .env/bin/activate
(.env)

Add libraries required for EC2 creation in setup.py

setup.py

(abridgement)
install_requires=[
        "aws-cdk.core",
        "aws_cdk.aws_ec2",
],
(abridgement)

pip update and install required libraries

# pip install -e .
(abridgement)
Successfully installed attrs-19.3.0 aws-cdk.aws-cloudwatch-1.32.1 aws-cdk.aws-ec2-1.32.1 aws-cdk.aws-events-1.32.1 aws-cdk.aws-iam-1.32.1 aws-cdk.aws-kms-1.32.1 aws-cdk.aws-logs-1.32.1 aws-cdk.aws-s3-1.32.1 aws-cdk.aws-ssm-1.32.1 aws-cdk.core-1.32.1 aws-cdk.cx-api-1.32.1 aws-cdk.region-info-1.32.1 cattrs-1.0.0 constructs-2.0.1 jsii-1.1.0 publication-0.0.3 python-dateutil-2.8.1 six-1.14.0 testcdk typing-extensions-3.7.4.2

Specify the deployment destination region with app.py

app.py

#!/usr/bin/env python3

from aws_cdk import core

from testcdk.testcdk_stack import TestcdkStack


app = core.App()
TestcdkStack(app, "testcdk", env=core.Environment(region="ap-northeast-1"))

app.synth()

Edit the testcdk / testcdk_stack.py file

Write a stack to create a VPC, SecurityGroup, EC2.

testcdk_stack.py

from aws_cdk import (
        core,
        aws_ec2 <=Add this
)


class TestcdkStack(core.Stack):

    def __init__(self, scope: core.Construct, id: str, **kwargs) -> None:
        super().__init__(scope, id, **kwargs)

        # The code that defines your stack goes here
        #Write the code below this

        cidr = '10.0.0.0/21'　#write cidr block

        vpc = aws_ec2.Vpc(
            self,
            id='test-vpc',
            cidr=cidr,
            nat_gateways=1,
            subnet_configuration=[
                aws_ec2.SubnetConfiguration(
                    cidr_mask=24,  #Define netmask for Public Subnet
                    name='public',
                    subnet_type=aws_ec2.SubnetType.PUBLIC,
                ),
                aws_ec2.SubnetConfiguration(
                    cidr_mask=24, #Define netmask for Private Subnet
                    name='private',
                    subnet_type=aws_ec2.SubnetType.PRIVATE,
                ),
            ],
        )

        security_group = aws_ec2.SecurityGroup(
            self,
            id='test-security-group',
            vpc=vpc,
            security_group_name='test-security-group'
        )

        security_group.add_ingress_rule(
            peer=aws_ec2.Peer.ipv4(cidr),
            connection=aws_ec2.Port.tcp(22), #Open Port 22 with Inbound
        )

        image_id = aws_ec2.AmazonLinuxImage(generation=aws_ec2.AmazonLinuxGeneration.AMAZON_LINUX_2).get_image(self).image_id #Specify EC2 image

        aws_ec2.CfnInstance(
            self,
            id='testec2',
            availability_zone="ap-northeast-1a", #Specify AZ
            image_id=image_id,
            instance_type="t3.micro", #Specify Instance Type
            key_name='testkey', #Specify Key Pair
            security_group_ids=[security_group.security_group_id],
            subnet_id=vpc.private_subnets[0].subnet_id, #Specify Private Subnet this time
            tags=[{
                "key": "Name",
                "value": "testec2"　#Define the name to display in the web console
            }]
        )

Check the stack for Cloudformation output by cdk synth

# cdk synth
Resources:
  testvpc8985080E:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: 10.0.0.0/21
      EnableDnsHostnames: true
      EnableDnsSupport: true
      InstanceTenancy: default
(abridgement)

You can also save the stack to yaml with cdk synth.

cdk synth > cdk.yaml

Check the list of deployable stacks

# cdk ls
testcdk

Deploy by specifying the created stack testcdk

# cdk deploy testcdk
testcdk: deploying...
testcdk creating CloudFormation changeset

Cloudformation will run in the specified AWS account region, and VPC and Subnet, Security Group, and EC2 will be created.

reference

Getting Started With the AWS CDK