Welcome back to the series of AWS Cloudformation For Beginners 👨🏻‍💻. In this blog we will be deploying AWS Private Subnet, AWS Nat Gateway, AWS Elastic Ip, AWS Private Route Table And Associate them accordingly.

If you are a beginner and want to start your journey towards infra-as-code developer as part of your devops role buckle up 🚴‍♂️ and lets get started and understand core cloudformation concepts by implementing it...🎬

❗️❗️❗️ Pre-Requisite ❗️❗️❗️

1️⃣ Add visual studio code extension [Mandatory]

2️⃣ Adding VS Code Indentation Extension For Cloudformation Templates [Optional]

3️⃣ Deploy VPC, IGW & Associate [Mandatory]

4️⃣ Deploy only public subnet template from below blog [Mandatory]

🌟Launch Private Subnet, Nat Gateway, Private Route Table & Associate🌟

Create Private Subnet, Nat Gateway, Elastic Ip, Private Route Table And Associate Private Route Table To Private Subnet so that access to internet can be made available in secure manner. 🔳 Parameters:-
✦ CustomVPC :- Using this parameter for VPC "AWS::EC2::VPC::Id" we can list existing VPC list into the account and select anyone from them. Apart from this list we can also you default value if no value is selected in the parameter.
✦ CustomInternetGateway :- Using this parameter for Internet gateway with type "String" we are setting default value for this parameter.
✦ PublicSubnet: Using this parameter for Subnet "AWS::EC2::Subnet::Id" we can list existing subnet list from the account and select anyone from them. Apart from this list we can also you default value if no value is selected in the parameter.
🔳 Resources
✦ PrivateSubnet:-Specifies a subnet for a VPC.When you create each subnet, you provide the VPC ID and IPv4 CIDR block for the subnet. After you create a subnet, you can't change its CIDR block. The size of the subnet's IPv4 CIDR block can be the same as a VPC's IPv4 CIDR block, or a subset of a VPC's IPv4 CIDR block.
✦ eipforNatGateway:-Specifies an Elastic IP (EIP) address and can, optionally, associate it with an Amazon EC2 instance.
✦ natGateway:-Specifies a network address translation (NAT) gateway in the specified subnet. You can create either a public NAT gateway or a private NAT gateway. The default is a public NAT gateway. If you create a public NAT gateway, you must specify an elastic IP address.
✦ PrivateRoute:-Specifies a route in a route table within a VPC.You must specify either DestinationCidrBlock or DestinationIpv6CidrBlock, plus the ID of one of the target resources.
✦ PrivateRouteTable:- Specifies a route table for a specified VPC. After you create a route table, you can add routes and associate the table with a subnet.
✦ PrivateSubnetARouteTableAssociation:-Associates a subnet with a route table. The subnet and route table must be in the same VPC. This association causes traffic originating from the subnet to be routed according to the routes in the route table. A route table can be associated with multiple subnets.
🔳 Outputs: Its always a best practice to print output for your resources.
✦ outputVPC: A reference to the created VPC.
✦ outputPrivateSubnets: A reference to the created Private Subnets.
✦ outputEipforNatGateway: A reference to the created EipforNatGateway.
✦ outputNatGateway: A reference to the created NatGateway.
✦ outputPrivateRouteTable: A reference to the created PrivateRouteTable.
✦ outputPrivateRoute: A reference to the created Private Route.
✦ outputPrivateSubnetRouteTableAssociation: A reference to the created PrivateSubnetRouteTableAssociation.

Parameters:
  CustomVPC:
    Description: Select One VPC available in your existing account
    Type: AWS::EC2::VPC::Id
    Default: <Default VPC ID>
  CustomInternetGateway:
    Description: Select One internet gateway available in your existing account
    Type: String
    Default: "<Internet gateway ID>"
   PublicSubnet:
    Description: Select one public subnet available in your existing account
    Type: AWS::EC2::Subnet::Id
    Default: "<Public subnet ID>"
Resources:
  PrivateSubnet:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone: !Select [ 0, !GetAZs '' ]
      MapPublicIpOnLaunch: true
      VpcId: !Ref CustomVPC
      CidrBlock: 10.0.0.64/26
      Tags:
        - Key: Name
          Value: PrivateSubnet
  eipforNatGateway:
    Type: AWS::EC2::EIP
    Properties:
      Domain: vpc
  natGateway:
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId: !GetAtt eipforNatGateway.AllocationId
      SubnetId: !Ref PublicSubnet
  PrivateRouteTable:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref CustomVPC
      Tags:
      - Key: Name
        Value: PrivateRouteTable
  PrivateRoute:
    Type: AWS::EC2::Route
    Properties:
      RouteTableId: !Ref PrivateRouteTable
      DestinationCidrBlock: 0.0.0.0/0    
      NatGatewayId: !Ref natGateway   # Route traffic through the NAT Gateway:
  PrivateSubnetARouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PrivateSubnet
      RouteTableId: !Ref PrivateRouteTable
Outputs:
  outputVPC:
    Description: A reference to the created VPC
    Value: !Ref CustomVPC
  outputPrivateSubnets:
    Description: A reference to the created Private subnet
    Value: !Ref PrivateSubnet
  outputEipforNatGateway:
    Description: A reference to the created EipforNatGateway
    Value: !Ref eipforNatGateway
  outputNatGateway:
    Description: A reference to the created NatGateway
    Value: !Ref natGateway
  outputPrivateRouteTable:
    Description: A reference to the created Private Route Table
    Value: !Ref PrivateRouteTable
  outputPrivateRoute:
    Description: A reference to the created Private Route
    Value: !Ref PrivateRoute
  outputPrivateSubnetRouteTableAssociation:
    Description: A reference to the created Private Subnet RouteTable Association
    Value: !Ref PrivateSubnetARouteTableAssociation

🔊 To view entire github code click here

1️⃣ Lets validate our template 👨‍💻

aws cloudformation validate-template --template-body file://<file path>

2️⃣ After successful template verification lets create stack using our template 👨‍💻

aws cloudformation create-stack --stack-name launchprivatesubnetwithnat --template-body file://<file path>

Note:- If you are not providing default vpc id in parameter then you will have to use below command

aws cloudformation create-stack --stack-name launchprivatesubnetwithnat --template-body file://<file path> --parameters ParameterKey=CustomVPC,ParameterValue=<VPC ID>

3️⃣ Check if the stack we created via template is completed successfully 👨‍💻

aws cloudformation list-stack-resources --stack-name launchprivatesubnetwithnat

4️⃣ Describe stack and its resources to view its properties 👨‍💻

aws cloudformation describe-stacks --stack-name launchprivatesubnetwithnat

aws cloudformation describe-stack-resources --stack-name launchprivatesubnetwithnat

5️⃣ Check events for stack formation 👨‍💻

aws cloudformation describe-stack-events --stack-name launchprivatesubnetwithnat

👁‍🗨👁‍🗨 YouTube Tutorial 📽

❗️❗️Important AWS Documentation To Be Viewed❗️❗️

⛔️ AWS::EC2::VPC
⛔️ AWS::EC2::InternetGateway
⛔️ AWS::EC2::Subnet
⛔️ AWS::EC2::RouteTable
⛔️ AWS::EC2::Route
⛔️ AWS::EC2::SubnetRouteTableAssociation
⛔️ Condition functions
⛔️ Managing route tables for your VPC
⛔️ AWS::EC2::EIP
⛔️ AWS::EC2::NatGateway

🥁🥁 Conclusion 🥁🥁

In this blog I have covered 1 usecases in which we will create
✦ Private Subnet,Nat Gateway, Elastic Ip, Private Route Table & Associate. I have used AWS CLI command to deploy these template and trust me AWS CLI is the realtime hero and I would suggest you to get acquainted towards it. Going forward I will be releasing further parts to this CloudFormation journey

📢Stay tuned for my next blog.....

🎊So, did you find my content helpful? If you did or like my other content, feel free to buy me a coffee. Thanks. 🎊

💫Cloudformation Series Sequence💫

🔰 Deploy VPC With Internet Gateway & Associate I
🔰 Public, Private Subnet & Route Table Creation & Association II
🔰 Private Subnet,Nat Gateway, Elastic Ip, Private Route Table & Associate III
🔰 NACL, Inbound & Outbound Routes, Security Group & Associate With Subnet IV
🔰 EC2 With Security Group & User Data & Mapping V
🔰 Target Group, Elastic Load Balancer & ELB Listener VI
🔰 Build Web Application Layer With AWS CloudFormation VII

⌛️Realtime Usecases Cloudformation Templates⏳

💨 Schedule Automatic Detection Of Unused AWS EBS Volumes & Notify
💨 Schedule Automatic Detection Of Non Associated AWS Elastic IP's In AWS Account On Weekly Basis And Notify
💨 Schedule Automatic Deregistration Of AWS AMI On Weekly Basis And Notify

👨🏻‍💻Cloudformation Github Repository👨🏻‍💻