AWS Classroomnotes 10/Aug/2023

Cloudformation (Contd)

• The template which we have helps you in creating the vpc with 3 subnets

{
    "Resources": {
        "ntiervpc": {
            "Type": "AWS::EC2::VPC",
            "Properties": {
                "CidrBlock": "10.10.0.0/16",
                "Tags": [
                    {
                        "Key": "Name",
                        "Value": "primaryvnet"
                    }
                ]
            }
        },
        "websubnet": {
            "Type": "AWS::EC2::Subnet",
            "Properties": {
                "AvailabilityZone": "ap-south-1a",
                "VpcId": {
                    "Ref": "ntiervpc"
                },
                "CidrBlock": "10.10.0.0/24",
                "Tags": [
                    {
                        "Key": "Name",
                        "Value": "web"
                    }
                ]
            }
        },
        "appsubnet": {
            "Type": "AWS::EC2::Subnet",
            "Properties": {
                "AvailabilityZone": "ap-south-1a",
                "VpcId": {
                    "Ref": "ntiervpc"
                },
                "CidrBlock": "10.10.1.0/24",
                "Tags": [
                    {
                        "Key": "Name",
                        "Value": "app"
                    }
                ]
            }
        },
        "dbsubnet": {
            "Type": "AWS::EC2::Subnet",
            "Properties": {
                "AvailabilityZone": "ap-south-1a",
                "VpcId": {
                    "Ref": "ntiervpc"
                },
                "CidrBlock": "10.10.2.0/24",
                "Tags": [
                    {
                        "Key": "Name",
                        "Value": "db"
                    }
                ]
            }
        }
    }
}

Change 1: Parametrize cidr ranges

• As of now the template always creates a network with range 10.10.0.0/16 and subnets with ranges
  • 10.10.0.0/24
  • 10.10.1.0/24
  • 10.10.2.0/24
• Lets give option to the user to pass values dynamically
• Refer Here for the changes done
  
  
• Refer Here for the fix in cloud formation list

Change 2: Attach internet gateway

• Create an internet gateway and attach it to the vpc
• Refer Here for the cf resource of internet gateway and Refer Here for attachment
• Refer Here for the changes
  
  

Change 3: Create a route table

• For manual steps refer class room video
• Refer Here for resource
• Create a route table with tag key = Name and value = Public
• Refer Here for the changes and Refer Here for the changeset to rename logical name
  
  

Exercise

• Create a route table with tag key = Name and value = Private

Concepts

• Refer Here for Cloudformation docs on parameters
• AWS allows us to pass values by using Cloudformation paramters,
• There are two types on paramters
  • user defined
  • AWS defined
• Supported types in paramters Refer Here