AWS - CloudFormation

CloudFormation Overview

JSON format definition about what service needs to be deployed
Infra as code

• Support JSON or YAML format

  • AWSTemplateFormatVersion : Format Version
  • Description
  • Parameters : define some params at stack creation time
  • Mappings: some predefined key/value pair, e.g, can be used to refer to value by region in resource def section
  • conditions , for example , if envcode=prod, then mount the disk when define the ec2 instance
  • “Resources” is the only mandatory section in CloudFormation def.
  • Outputs: can be used to be imported into other stack or report/show on console

• CloudFormer

  • only support JSON
  • export current account’s selected service into cloudformation definition
  • Visual Tool to edit the cloudformation json template

  Sensitive Parameters (NoEcho)
  https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/parameters-section-structure.html

  Automatic Roll Back on Failure
  https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/troubleshooting.html

049.mp4 050.mp4 051.mp4 - hands on cloudformation

• Create cloudformation template using JSON editor

  • manually add “AWSTemplateFormatVersion”,“Description”,“Parameters”,“Resources”,“Outputs”
  • pre-defined copied: define a DynamoDB with
    • Parameters: ReadCapacityUnit and WriteCapacityUnit
    • Resources: DynamoDB Table with attributes definitions
    • Outputs: print out the table name
  • from AWS console , from “CloudFormation” service main page, select “create a new stack”
    • template can from sample / upload one to S3 / from a URL (hosted in S3)
    • Roll back on failure is “On” by default
  • swith to DynamoDB console, and check the table is created as expected.

• Create Cloudformation using CloudFormer

  • Create a stack and select “template from sample” and choose the “Cloudformer” template
    • give user and password to login CloudFormer (took 8 min to create from video)
    • output contains the url of the CloudFormer webpage
  • Login CloudFormer
    • create template
    • go through the wizard to select from existing resources as template to form the new template
    • note: it won’t define paramteters (directly copy from the existing resources)
  • Launch the stack using the template created by CloudFormer

CloudFormation Desinger

• Visualize the Design
• Can be used to update existing stack

Extend with custom resources

Capability to create resource that implement aws defined create/update/rollback/delete and metadata

Standard Senario: use lambda

Security

Policy example

• limit an user to only have access to create stack using template from certain bucket
• limit a user to only can update a stack using a specific yml from a certain bucket

IAM policy example

• limit type of resources the user can create

Best Practise

• reuse accross Region
• Pseudo parameters (make use of the environment parameters)
• Use Mappings
• Use Conditionals

References

047.mp4 048.mp4

CloudFormation Designer
https://youtu.be/fVMlxJJNmyA