AWS Classroomnotes 25/Mar/2023

Infrastructure as Code (IaC)

• This represents expressing infra as a Desired state and let the IaC tool do the rest.
• Popular IaC tools
  • Terraform
  • Cloud Formation
  • ARM Templates
  • Azure Bicep

AWS Cloudformation

• AWS Cloudformation, allows us to express the desired state in json or yaml format and when executed (Created stack) will create infra
• Workflow
  • Author a template
  • upload to s3 directly or indirectly
  • Creates changeset (what has to be created/updated)
  • Executes to realize infra.
    
• Refer Here for CF concepts
• Template: Desired state expressed in json or yaml
• Stack: Represents the execution of Template
• Changeset: This represents the infra to be updated/created/deleted.
• To author an Cloud formation template
  • JSON/YAML Knowledge
  • Manual steps of how to create infra
  • Productivity:
    • Visual Studio Code with Cloudformation extension
      

Cloudformation Template Grammar/Syntax

• Refer Here for AWS CF Template syntax
• Json

{
  "AWSTemplateFormatVersion" : "version date",

  "Description" : "JSON string",

  "Metadata" : {
    template metadata
  },

  "Parameters" : {
    set of parameters
  },

  "Rules" : {
    set of rules
  },

  "Mappings" : {
    set of mappings
  },

  "Conditions" : {
    set of conditions
  },

  "Transform" : {
    set of transforms
  },

  "Resources" : {
    set of resources
  },

  "Outputs" : {
    set of outputs
  }
}

• YAML

---
AWSTemplateFormatVersion: "version date"

Description:
  String

Metadata:
  template metadata

Parameters:
  set of parameters

Rules:
  set of rules

Mappings:
  set of mappings

Conditions:
  set of conditions

Transform:
  set of transforms

Resources:
  set of resources

Outputs:
  set of outputs

• Template sections Refer Here
• For now lets look at three template secions
  • Format Version: Refer Here
  • Description Refer Here
  • Resources Refer Here
• Skeleton(json):

{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Description": "",
    "Resources": {

    }
}

• Skeleton (YAML):

---
AWSTemplateFormatVersion: '2010-09-09'
Description: ''
Resources: {}

Activity 1: Create an S3 bucket using Cloud formation

• Way of Working (WoW):
  • Manual steps for creation
  • Lets make a note of inputs which we provide while creating s3 bucket
• Manual Steps:
  
  
  
  
  
  
• Search for resource type and syntax
  
• s3 resource in cloud formation Refer Here
• Refer Here for the template created
• Create stack:
  
  
  
  
  
  
  
  

Activity 2: Create a vpc

• Refer Here for manual steps
• inputs
  • Name tag
  • cidr: 192.168.0.0/16
• Create stack from the template
  
  

Exercises:

• Create a cloudformation template to
  • Create a user in IAM
  • Create a group in IAM