example of cloudformation Metadata, Parameters and Outputs section

In This tutorial we are introducing another CF sections, which as follow.

1) Metadata: section lets you associate a resources with structured data(in sequence) during the template runtime.

2) Parameters: section enable you to input custom values to your template its also appeared during the stack creation.

3) Outputs: section declares output values that you can import into other stacks (to create cross-stack references) or view the output value on the AWS CloudFormation console. For example, you can get output of the EC2 Instance Elastic ip address.
 

Step 1) Let's Define the Metadata Section in Yaml.

Note: Metadata Section depends on Parameters Section.

Metadata: AWS::CloudFormation::Interface: ParameterGroups: - Label: default: "VPC CIDR" Parameters: - VpcCIDR - Label: default: "Subnet CIDR" Parameters: - SubnetCIDR - Label: default: "EC2" Parameters: - InstanceImageID - InstanceType - SSHPublicKey - SSHLocation

Step 2) Let's Define the Parameters Section in Yaml.

Parameters: VpcCIDR: Default: 10.0.0.0/16 Description: Please enter the IP range (CIDR notation) for this VPC Type: String SubnetCIDR: Default: 10.0.1.0/24 Description: Please enter the IP range (CIDR notation) for this Subnet Type: String InstanceImageID: Default: ami-0574da719dca65348 Description: Please enter EC2 Instance Image ID Type: String InstanceType: Default: "t2.micro" Description: Please enter EC2 Instance Type Type: String SSHPublicKey: Default: ssh-rsa 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 administrator@administrator Description: Please enter SSH Public Key Type: String SSHLocation: AllowedPattern: '(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})/(\d{1,2})' ConstraintDescription: must be a valid IP CIDR range of the form x.x.x.x/x. Default: 0.0.0.0/0 Description: The IP address range that can be used to access the EC2 using SSH. MaxLength: '18' MinLength: '9' Type: String

 

Step 3) Let's Define the Resources Section in Yaml.

 

Resources: MYVPC: Type: AWS::EC2::VPC Properties: CidrBlock: !Ref VpcCIDR EnableDnsSupport: 'true' EnableDnsHostnames: 'true' InstanceTenancy: default Tags: - Key: Name Value: My Demo VPC MYSUBNET: Type: AWS::EC2::Subnet Properties: VpcId: !Ref MYVPC CidrBlock: !Ref SubnetCIDR AvailabilityZone: "us-east-1a" Tags: - Key: Name Value: My Demo Public Subnet MYIGW: Type: AWS::EC2::InternetGateway Properties: Tags: - Key: Name Value: My Demo IGW IGWATTACHTOVPC: Type: AWS::EC2::VPCGatewayAttachment Properties: InternetGatewayId: !Ref MYIGW VpcId: !Ref MYVPC MYROUTETABLE: Type: AWS::EC2::RouteTable Properties: VpcId: !Ref MYVPC Tags: - Key: Name Value: My Demo Route Table PUBLICROUTE: Type: AWS::EC2::Route Properties: DestinationCidrBlock: 0.0.0.0/0 GatewayId: !Ref MYIGW RouteTableId: !Ref MYROUTETABLE SUBNETROUTETABLEASSOCIATION: Type: AWS::EC2::SubnetRouteTableAssociation Properties: RouteTableId: !Ref MYROUTETABLE SubnetId: !Ref MYSUBNET MYEC2INSTANCE: Type: AWS::EC2::Instance Properties: ImageId: !Ref InstanceImageID InstanceType: !Ref InstanceType SubnetId: !Ref MYSUBNET KeyName: !Ref MYEC2KEYPAIR SecurityGroupIds: - !Ref MYSG Tags: - Key: Name Value: My Demo EC2 Instance UserData: Fn::Base64: !Sub | #!/bin/bash -xe sudo su apt update -y apt install apache2 -y echo "ApacheWebServer" > /var/www/html/index.html service apache2 start MYEC2KEYPAIR: Type: AWS::EC2::KeyPair Properties: KeyName: my demo pem file PublicKeyMaterial: !Ref SSHPublicKey Tags: - Key: Name Value: My Demo EC2 Keypair MYEIP: Type: AWS::EC2::EIP Properties: InstanceId: !Ref MYEC2INSTANCE Tags: - Key: Name Value: My Demo EIP For EC2 MYSG: Type: AWS::EC2::SecurityGroup Properties: GroupDescription: Allow http to client host VpcId: !Ref MYVPC SecurityGroupIngress: - IpProtocol: tcp FromPort: 80 ToPort: 80 CidrIp: 0.0.0.0/0 - IpProtocol: tcp FromPort: 22 ToPort: 22 CidrIp: !Ref SSHLocation SecurityGroupEgress: - IpProtocol: -1 CidrIp: 0.0.0.0/0 Tags: - Key: Name Value: My Demo SG For EC2

 

Step 4) Let's Define the Outputs Section in Yaml.

 

Outputs: # Export VPC ID VPC: Description: VPC ID Export: Name: !Sub ${AWS::StackName}-MYVPC Value: !Ref MYVPC # Export Public Subnet 1 MYSUBNET: Description: Public Subnet ID Export: Name: !Sub ${AWS::StackName}-MYSUBNET Value: !Ref MYSUBNET # Export EC2 Public DNS WebServerPublicDNS: Description: 'Public DNS of EC2 instance' Export: Name: !Sub ${AWS::StackName}-WebServerPublicDNS Value: !GetAtt MYEC2INSTANCE.PublicDnsName # Export EC2 Instance Elastic Ip Address WebServerElasticIP: Description: 'Elastic IP assigned to EC2' Export: Name: !Sub ${AWS::StackName}-WebServerElasticIP Value: !Ref MYEIP

" If You are Still Struggling to align all the Resources into single template,

So don't worry I am sharing complete template below."

AWSTemplateFormatVersion: '2010-09-09' Description: Template to Create an EC2 instance, EIP and associate with instance Metadata: AWS::CloudFormation::Interface: ParameterGroups: - Label: default: "VPC CIDR" Parameters: - VpcCIDR - Label: default: "Subnet CIDR" Parameters: - SubnetCIDR - Label: default: "EC2" Parameters: - InstanceImageID - InstanceType - SSHPublicKey - SSHLocation Parameters: VpcCIDR: Default: 10.0.0.0/16 Description: Please enter the IP range (CIDR notation) for this VPC Type: String SubnetCIDR: Default: 10.0.1.0/24 Description: Please enter the IP range (CIDR notation) for this Subnet Type: String InstanceImageID: Default: ami-0574da719dca65348 Description: Please enter EC2 Instance Image ID Type: String InstanceType: Default: "t2.micro" Description: Please enter EC2 Instance Type Type: String SSHPublicKey: Default: ssh-rsa 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 administrator@administrator Description: Please enter SSH Public Key Type: String SSHLocation: AllowedPattern: '(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})/(\d{1,2})' ConstraintDescription: must be a valid IP CIDR range of the form x.x.x.x/x. Default: 0.0.0.0/0 Description: The IP address range that can be used to access the EC2 using SSH. MaxLength: '18' MinLength: '9' Type: String Resources: MYVPC: Type: AWS::EC2::VPC Properties: CidrBlock: !Ref VpcCIDR EnableDnsSupport: 'true' EnableDnsHostnames: 'true' InstanceTenancy: default Tags: - Key: Name Value: My Demo VPC MYSUBNET: Type: AWS::EC2::Subnet Properties: VpcId: !Ref MYVPC CidrBlock: !Ref SubnetCIDR AvailabilityZone: "us-east-1a" Tags: - Key: Name Value: My Demo Public Subnet MYIGW: Type: AWS::EC2::InternetGateway Properties: Tags: - Key: Name Value: My Demo IGW IGWATTACHTOVPC: Type: AWS::EC2::VPCGatewayAttachment Properties: InternetGatewayId: !Ref MYIGW VpcId: !Ref MYVPC MYROUTETABLE: Type: AWS::EC2::RouteTable Properties: VpcId: !Ref MYVPC Tags: - Key: Name Value: My Demo Route Table PUBLICROUTE: Type: AWS::EC2::Route Properties: DestinationCidrBlock: 0.0.0.0/0 GatewayId: !Ref MYIGW RouteTableId: !Ref MYROUTETABLE SUBNETROUTETABLEASSOCIATION: Type: AWS::EC2::SubnetRouteTableAssociation Properties: RouteTableId: !Ref MYROUTETABLE SubnetId: !Ref MYSUBNET MYEC2INSTANCE: Type: AWS::EC2::Instance Properties: ImageId: !Ref InstanceImageID InstanceType: !Ref InstanceType SubnetId: !Ref MYSUBNET KeyName: !Ref MYEC2KEYPAIR SecurityGroupIds: - !Ref MYSG Tags: - Key: Name Value: My Demo EC2 Instance UserData: Fn::Base64: !Sub | #!/bin/bash -xe sudo su apt update -y apt install apache2 -y echo "ApacheWebServer" > /var/www/html/index.html service apache2 start MYEC2KEYPAIR: Type: AWS::EC2::KeyPair Properties: KeyName: my demo pem file PublicKeyMaterial: !Ref SSHPublicKey Tags: - Key: Name Value: My Demo EC2 Keypair MYEIP: Type: AWS::EC2::EIP Properties: InstanceId: !Ref MYEC2INSTANCE Tags: - Key: Name Value: My Demo EIP For EC2 MYSG: Type: AWS::EC2::SecurityGroup Properties: GroupDescription: Allow http to client host VpcId: !Ref MYVPC SecurityGroupIngress: - IpProtocol: tcp FromPort: 80 ToPort: 80 CidrIp: 0.0.0.0/0 - IpProtocol: tcp FromPort: 22 ToPort: 22 CidrIp: !Ref SSHLocation SecurityGroupEgress: - IpProtocol: -1 CidrIp: 0.0.0.0/0 Tags: - Key: Name Value: My Demo SG For EC2 Outputs: # Export VPC ID VPC: Description: VPC ID Export: Name: !Sub ${AWS::StackName}-MYVPC Value: !Ref MYVPC # Export Public Subnet 1 MYSUBNET: Description: Public Subnet ID Export: Name: !Sub ${AWS::StackName}-MYSUBNET Value: !Ref MYSUBNET # Export EC2 Public DNS WebServerPublicDNS: Description: 'Public DNS of EC2 instance' Export: Name: !Sub ${AWS::StackName}-WebServerPublicDNS Value: !GetAtt MYEC2INSTANCE.PublicDnsName # Export EC2 Instance Elastic Ip Address WebServerElasticIP: Description: 'Elastic IP assigned to EC2' Export: Name: !Sub ${AWS::StackName}-WebServerElasticIP Value: !Ref MYEIP