DevOps Classroomnotes 31/Mar/2023

Terraform Contd…

Terraform Modules

• Terraform modules are reusable terraform templates
• There are lot of community modules on terraform registry
• Module demo Refer Here for module usage with aws
• To create ec2 Refer Here

Terraform provisioners

• Provisioners are for performing activities in local or remote instance after resource creation
  • local Refer Here
  • remote Refer Here

Terraform interview questions

• What is terraform
• What is infrastructure as Code
• Can Ansible replace Terraform
• What is resource, argument and attribute
• What is terraform lifecycle:
  • here we have three stages
    • create
    • modify
    • delete
  • actions:
    • op
    • no-op
• What is terraform registry: this is collection of modules
• How to use two providers
  • use alias

provider "aws" {
region = "us-west-2"
alias = red
}

provider "aws" {
region = "us-west-2"
alias = green
}

resource "aws_vpc" "red_vpc" {
provider = aws.red
}

resource "aws_vpc" "green_vpc" {
provider = aws.green
}

• How to use terraform in ci/cd pipeline
  • on jenkins node install terraform
  • sh terraform apply -auto-approve
  • azure devops:
    • bash terraform apply -auto-approve
    • Terraform market place
• What is the purpose of backend
• What is the purpose of workspace
• Write one terraform template to do resource creation
• How to do zero down time deployments in terraform
  • Create tags and apply terraform only of specific tags
  • Use count with conditions
• How to delete the resource which is managed by terraform

terraform state rm <resource-path>

• How to delete and recreate the resource during next apply

terraform taint <resource-path>