DevOps Classroom notes 01/Jun/2025

Datasources

• Datasources are used to fetch information about resources.
• Datasource will not create any thing, rather it fetches information and Refer Here for official docs
• Refer Here for datasources example

How does terraform know what it has created

• Terraform on execution will create a file called as terraform.tfstate locally in the same directory where the terraform is executed from.
• This state file contains the information about the resources created in this execution
• Terraform during execution, will check if there is a state file. If the state file exists,
  • it takes backup of the current state file
  • it executes the refresh internally to get the current state
  • difference between what we want vs current state becomes plan
  • Terraform executes the plan
• Terraform apply => refresh + plan + apply
• Since the state file is present in the local folder, to make the template available for multi users, it is recommended to use Terrform Backends (Common state storage )
  

Activity 1: ntier in Azure

• Overview
  
• Manual steps: Watch classroom recording
• summary
  • create resource group
  • create virtual network with subnets
  • create a network resource groups
  • create virtual machines
  • login into vms and install necessary softwares
• create resource group Refer Here for changes.
• As a best practice, lets start using terrascan