Pulumi - Create AWS EC2 instance (existing VPC)

Introduction

In this post, we used Pulumi to create an EC2 instance in the default VPC. What follows is going to be a small variation on that post since we will create an EC2 instance but we will place it in an existing VPC that was created before already.

Begin situation

We have created manually already a VPC and some subnets. Here we have:

  • VPC: pulumi-vpc with CIDR 10.0.0.0/16
  • Subnet 1: pulumi-subnet 1 with CIDR 10.0.24.0/20
  • Subnet 2: pulumi-subnet 2 with CIDR 10.0.32.0/20

Below is a screenshot of the VPC:

pulumi

And here is a screenshot of the subnets:

pulumi

The code for this small blog post can be found here.

Pulumi code

In terms of code, it’s not so much different from what we did in this post. However, here we are using the aws.ec2.Vpc.get function to retrieve the VPC based on its name and id. The subnet, we retrieve by using the aws.ec2.get_subnet function.

import pulumi
import pulumi_aws as aws

size = 't3.micro'

user_data = """#!/bin/bash
echo "Hello, World!" > index.html
nohup python -m SimpleHTTPServer 8080 &
"""

ami = aws.ec2.get_ami(most_recent="true",
                  owners=["137112412989"],
                  filters=[{"name":"name","values":["amzn-ami-hvm-*"]}])

my_vpc = aws.ec2.Vpc.get(resource_name="pulumi-vpc", id="vpc-0fe55d86283f0705c")

my_subnet =  aws.ec2.get_subnet(filters=[aws.ec2.GetSubnetFilterArgs(
    name="tag:Name",
    values=["pulumi-subnet-1"],
)])

group = aws.ec2.SecurityGroup('pulumi_allow_8080',
            vpc_id=my_vpc.id,
            description='Enable access to port 8080',
            ingress=[
                { 'protocol': 'tcp', 'from_port': 8080, 'to_port': 8080, 'cidr_blocks': ['0.0.0.0/0'] },
                { 'protocol': 'tcp', 'from_port': 22, 'to_port': 22, 'cidr_blocks': ['0.0.0.0/0'] }
            ])

server = aws.ec2.Instance('webserver',
    instance_type=size,
    vpc_security_group_ids=[group.id], 
    ami=ami.id,
    subnet_id=my_subnet.id,
    user_data = user_data,
    tags = { "Name": "Pulumi" },
    )
    
pulumi.export('publicIp', server.public_ip)
pulumi.export('publicHostName', server.public_dns)

In order to run the script, we can simply use the pulumi up command:

/Webserver/Pulumi_existingVPC❯ pulumi up 
Please choose a stack, or create a new one: dev
Previewing update (dev)

View Live: https://app.pulumi.com/wiwa1978/aws_ec2_wim/dev/previews/72afd6c3-ba80-44dd-bdc0-05d895d45a28

     Type                      Name               Plan       
 +   pulumi:pulumi:Stack       aws_ec2_wim-dev    create     
 +   ├─ aws:ec2:SecurityGroup  pulumi_allow_8080  create     
 +   └─ aws:ec2:Instance       webserver          create     
 
Resources:
    + 3 to create

Do you want to perform this update? yes
Updating (dev)

View Live: https://app.pulumi.com/wiwa1978/aws_ec2_wim/dev/updates/20

     Type                      Name               Status      
 +   pulumi:pulumi:Stack       aws_ec2_wim-dev    created     
 +   ├─ aws:ec2:SecurityGroup  pulumi_allow_8080  created     
 +   └─ aws:ec2:Instance       webserver          created     
 
Outputs:
    publicHostName: "ec2-3-120-158-193.eu-central-1.compute.amazonaws.com"
    publicIp      : "3.120.158.193"

Resources:
    + 3 created

Duration: 23s

The final result can be seen below:

pulumi

Code for this small variant can be found here.