What is the difference between Terraform local and remote state?

Terraform state can be stored locally (on disk) or remotely (in S3, Consul, etc.).

Example remote state (S3 backend):

terraform {
  backend "s3" {
    bucket = "my-terraform-state"
    key    = "prod/terraform.tfstate"
    region = "us-east-1"
  }
}

How do you handle secrets in Terraform?

Avoid hardcoding secrets in .tf files:
✅ Use environment variables
✅ Use Terraform Vault Provider
✅ Store secrets in AWS Secrets Manager

What is Terraform Locking, and why is it important?

Terraform uses state locking to prevent simultaneous updates by multiple users.

Example (DynamoDB locking):

backend "s3" {
  bucket         = "my-terraform-bucket"
  dynamodb_table = "terraform-lock"
}

What is Terraform Workspaces?

Terraform Workspaces allow managing multiple environments within a single configuration.

terraform workspace new dev
terraform workspace select dev

How do you create reusable Terraform modules?

Modules help organize and reuse code.

Example (modules/network/main.tf):

variable "vpc_cidr" {}

resource "aws_vpc" "main" {
  cidr_block = var.vpc_cidr
}

How do you use Ansible variables?

Variables can be defined in:
✅ Playbooks (vars:)
✅ Inventory (host_vars, group_vars)
✅ Command-line (-e flag)

Example:

- hosts: web
  vars:
    app_port: 8080
  tasks:
    - debug: msg="App runs on port {{ app_port }}"

What are Ansible Facts?

Facts are system information collected automatically.

Example:

ansible all -m setup

What is the purpose of Ansible Handlers?

Handlers run only when notified.

Example:

- name: Install Nginx
  apt:
    name: nginx
  notify: Restart Nginx

handlers:
  - name: Restart Nginx
    service:
      name: nginx
      state: restarted

What are the main components of AWS CloudFormation?

How do you update a CloudFormation stack?

Use:

aws cloudformation update-stack --stack-name my-stack --template-body file://template.yml

What is the difference between DependsOn and CreationPolicy in CloudFormation?