Build a VPC with CloudFormation

Last Updated : 28 Mar, 2023

Pre-requisite: AWS

AWS or Amazon Web Services, Inc. is a sub-division of Amazon that offers on-demand cloud computing platforms and APIs for individuals, companies, and governments. CloudFormation is one of the services provided by Amazon Web Services, that helps the client model and set up their own AWS resources to save their time on managing those resources and they get to have more time focusing on their applications that run in AWS instead.

Basically, CloudFormation is a method that helps provision AWS infrastructure through code. It enables the user to quickly and consistently provide a group of related AWS and external resource models. Additionally, AWS CloudFormation offers a way to manage the resources throughout their lifespan. Here in this article, we’ll discuss a primary method to build a VPC through the CloudFormation of Amazon Web Services.

Build a VPC with CloudFormation

Cloudformation is a tool that helps the user to create and manage AWS resources easily. It can be used to manage all AWS resources using a text file. Cloudformation allows the user to create and model the infrastructure and applications without having to perform actions manually. through this, it is easy to manage infrastructure in a text file, or template. Cloudformation template is a formatted text file in JSON or YAML language that describes the AWS infrastructure.

Getting started with the AWS

Step 1: To start, the first step requires logging in to the AWS account. For this purpose, we can use the link given here to go to AWS Login Page. As soon as we click on the link, we will be shown a web page as we can see in the image below:

Step 2: Here fill out all the required details to log in. once we are done with the logging process, a main console window will show up as we can see in the image below:

Step 3: here, before proceeding further, we require a template that we will use to create a VPC. For this, we can use an exemplary template as given ahead. Just needs to Copy the following code and save it on a local machine.

Description: This template creates a VCC with 
two Public and two Private subnets, spread 
  across two availability zones. It builds 
  an internet gateway with a default 
  route on the public subnets.
  
  Parameters:
    EnvironmentName:
      Description:  An environment name that precedes resource names.
      Type: String
      
    VpcCIDR:
      Description: Please enter the IP range for this VPC
      Type: String
      Default: 10.8.0.0/16
   
    PublicSubnet1CIDR: 
      Description: Please enter the IP range  for
       the public subnet in the first Availability Zone
      Type: String
      Default: 10.8.10.0/24
        
    PublicSubnet2CIDR:
      Description: Please enter the IP range  for 
      the public subnet in the second Availability Zone
      Type: String
      Default: 10.8.11.0/24
        
    PrivateSubnet1CIDR:
      Description: Please enter the IP range  for 
      the private subnet in the first Availability Zone
      Type: String
      Default: 10.8.21.0/24
        
    PrivateSubnet2CIDR:
      Description: Please enter the IP range for 
      the private subnet in the second Availability Zone
      Type: String
      Default: 10.8.21.0/24
      
  Resources:
    VPC:
      Type: AWS::EC2::VPC
      Properties:
        CidrBlock: !Ref VpcCIDR
        EnableDnsSupport: true 
        EnableDnsHostnames: true
        Tags:
          - Key:Name
            Value: !Ref EnvironmentName
            
    InternetGateway:
      Type: AWS::EC2::InternetGateway
      Properties:
        Tags:
          - Key: Name
            Value: !Ref EnvironmentName
            
    InternetGatewayAttachment:
      Type: AWS::EC2::VPCGatewayAttachement
      Properties:
        InternetGatewayId: !Ref InternetGateway
        VpcId: !Ref VPC
        
    PublicSubnet1:
      Type: AWS::EC2::Subnet
      Properties:
        VpcId: !Ref VPC
        AvailibilityZone: !Select [ 0, !GetAZs '' ]
        CidrBlock: !Ref PublicSubnet1CIDR
        MapPublicIpOnLaunch: true
        Tags:
          - Key: Name
            Value:  !Sub ${EnvironmentName} Public Subnet (AZ1)
              
    PublicSubnet2:
      Type: AwS::EC2::Subnet
      Properties:
        VpcId: !Ref VPC
        AvailabilityZone: !Select [ 1, !GetAZs  '' ]
        CidrBlock: !Ref PublicSubnet2CIDR
        MapPublicIpOnLaunch: True
        Tags:
          - Key: Name
            Value: !Sub ${EnvironmentName} Public Subnet (AZ2)
              
    PrivatSubnet1:
      Type: AWS::EC2::Subnet
      Properties:
        VpcId: !Ref VPC
        AvailabilityZone: !Select [ 0, !GetAZs  '' ]
        CidrBlock: !Ref PrivateSubnet1CIDR
        MapPublicIpOnLaunch: false
        Tags:
          - Key: Name
            Value: !Sub ${EnvironmentName} Private Subnet (AZ1)
              
    PrivateSubnet2:
      Type: AWS::EC2::Subnet
      Properties: 
        VpcId: !Ref VPC
        AvailabilityZone: !Select [ 1, !GetAZs  '' ]
        CidrBlock: !Ref PrivateSubnet2CIDR
        MapPublicIpOnLaunch: false
        Tags:
          - Key: Name
            Value: !Sub ${EnvironmentName} Private Subnet (AZ2)
              
     PublicRouteTable:
       Type: AWS::EC2::RouteTable
       Properties:
         VpcId: !Ref VPC
         Tags:
           - Key: Name
             Value: !Sub ${EnvironmentName} Public Routes
             
     DefaultPublicRoute:
       Type: AWS::EC2::Route
       DependsOn: InternetGatewayAttachment
       Properties:
         RouteTableId: !Ref PublicRouteTable
         DestinationCidrBlock: 0.0.0.0/0
         GetewayId: !Ref InternetGateway
         
     PublicSubnet1RouteTabletAssociation:
       Type: AWS::EC2::SubnetRouteTableAssociation
       Properties:
         RouteTableId: !Ref PublicRouteTable
         SubnetId: !Ref PublicSubnet1
         
     PublicSubnet2RouteTableAssociation:
       Type: AWS::EC2:: SubnetRouteTableAssociation
       Properties:
         RouteTable: !Ref PublicRouteTable
         SubnetId: !Ref PublicSubnet2
         
         
     PrivateRouteTable1:
       Type: AWS::EC2::RouteTable
       Properties:
         VpcId: !Ref VPC
         Tags:
           - Key: Name
             Value: !Sub ${EnvironmentName} Private Routes (AZ1)
               
     PrivateSubnet1RouteTableAssociation:
       Type: AWS::EC2::SubnetRouteTableAssocoiation
       Properties:
         RouteTableId: !Ref PrivateRouteTable1
         SubnetId: !Ref PrivateSubnet1
         
     PrivateRouteTable2:
       Type: AWS::EC2::RouteTable
       Properties:
         VpcId: !Ref VPC
         Tags:
           - Key: Name
           Value: !Sub ${EnvironmentName} Private Routes (AZ2)
          
     PrivateSubnet2RouteTableAssociation:
       Type: AWS::EC2::SubnetRouteTableAssociation
       Propreties:
         RouteTableId: !Ref PrivateRouteTable2
         SubnetId: !Ref PrivateSubnet2
         
     NoIngressSecurityGroup:
       Type: AWS::EC2::SecurityGroup
       Properties:
         GroupName: "no-ingress-sg"
         GroupDescription: "Security group with no ingress rule"
         VpcId: !Ref VPC
         
   Outputs:
     VPC:
       Description: A reference to the created VPC
       Value: !Ref VPC
       
     PublicSubnets:
       Description: A list of the public subnets
       Value: !join [ ",", [ !Ref PublicSubnet1, !Ref PublicSubnet2 ]]
       
     PrivateSubnets:
       Description: A list of the private subnets
       Value: !join [ ",", [ !Ref PrivateSubnet1, !Ref PrivateSubnet2 ]]
         
     PublicSubnet1:
       Description: A reference to the public subnet in the 1st Availability Zone
       Value: !Ref PublicSubnet1  
         
     PublicSubnet2:
       Description: A reference to the public subnet in the 2nd Availability Zone
       Value: !Ref PublicSubnet2        
              
     PrivateSubnets:
       Description: A reference to the private subnet in the 1st Availability Zone
       Value: !Ref PrivateSubnet1  
              
     PrivateSubnets:
       Description: A reference to the private subnet in the 2nd Availability Zone
       Value: !Ref PrivateSubnet2
       
       NoIngressSecrityGroup:
         Description: Security group with no ingress rule
         Value: !Ref NoIngressSecurityGroup

Building a CloudFormation Stack

Step 1: To create a CloudFormation Stack, first, click on the “Services” option in the top left of the screen, and then, search for the “CloudFormation” option and click on it. As we can see in the image below:

Step 2: On the dashboard, click on the “Create stack” button and select the first option, “With new resources (standard)”. As in the image below:

Step 3: A template file is required for the stack, which can be either a local file or an object file in an S3 bucket. here, we will be using a local template. First, select the local template file by clicking on the “Template is ready” button, next “Upload a template file”, then click on “Choose file” to continue

Step 4: here create a name for the stack. We can make some other changes as required. However, here we will keep all other parameters as it is for now.

next, as given in the options, we can create Tags according to our work requirements.

Step 5: Now, scroll down the page and click on the “Create stack” button, as shown in the image:

Wait for a while, as it might take a few moments.

Under the “Events” tab, we can see the current status or event data.

Step 6: We can now visit VPC and look for the newly created VPC there. Click “Services” at the top and then use the left search bar to find VPC to access it.