CloudFormation

https://aws.amazon.com/cloudformation/

Docs: https://docs.aws.amazon.com/cloudformation/index.html

https://github.com/donnemartin/awesome-aws#cloudformation

Validate Infrastructure-as-code (IaC) or infrastructure/service compositions such as CloudFormation Templates, CloudFormation ChangeSets, Terraform JSON configuration files, Kubernetes configurations - https://github.com/aws-cloudformation/cloudformation-guard

https://github.com/Sceptre/sceptre - https://docs.sceptre-project.org

Linter: https://github.com/aws-cloudformation/cfn-lint

Never store sensitive information (such as credentials and access keys) in a template file.

A stack can be created using the console or the CLI.

CLI

CLI Reference: https://docs.aws.amazon.com/cli/latest/reference/cloudformation/index.html

Sample templates

• https://aws.amazon.com/cloudformation/resources/templates
• https://github.com/widdix/aws-cf-templates
• Static site S3 CloudFront - https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/getting-started-secure-static-website-cloudformation-template.html - https://github.com/aws-samples/amazon-cloudfront-secure-static-site

Template sections

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/template-anatomy.html

All sections are optional except Resources. The order of the sections does not matter.

AWSTemplateFormatVersion: 2010-09-09

Description: >
  Here are some details about
  the template.

Parameters:
  InstanceTypeParameter:
    Type: String
    Default: t2.micro
    AllowedValues:
      - t2.micro
      - m1.small
      - m1.large
    Description: Enter t2.micro, m1.small, or m1.large. Default is t2.micro.

Resources:
  MyEC2Instance:
    Type: "AWS::EC2::Instance"
    Properties:
      ImageId: "ami-0ff8a91507f77f867"

Outputs:
  StackVPC:
    Description: The ID of the VPC
    Value: !Ref MyVPC
    Export:
      Name: !Sub "${AWS::StackName}-VPCID"

Format version AWSTemplateFormatVersion

• https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/format-version-structure.html
• The only valid value is 2010-09-09

Description

• https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/template-description-structure.html
• String between 0 and 1024 bytes
• Displayed on the console

Parameters

• https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/parameters-section-structure.html
• Like variables. Used to avoid hardcoding values and make the template reusable
• Set when the stack is created
• Used in Resources and Outputs sections
• The Type field is required, the rest are optional

Resources

• https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/resources-section-structure.html
• Required
• Properties depend on the resource type

Outputs

• https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/outputs-section-structure.html
• Resources that you can reuse in other stacks
• View them with aws cloudformation describe-stacks
• Use ImportValue to get the value exported by another stack

Metadata

• https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/metadata-section-structure.html

Intrinsic functions

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-sub.html

CLI

Create stack: aws cloudformation create-stack --stack-name myStackName --region us-east-1 --template-body file://myTemplate.yml

Update stack: aws cloudformation update-stack --stack-name myStackName --region us-east-1 --template-body file://myTemplate.yml

Describe stack: aws cloudformation describe-stacks --stack-name myStackName

Delete stack: aws cloudformation delete-stack --stack-name myStackName