Skip to main content

Terraform

Providers​

Random Provider | Shuffle Resource​

resource "random_shuffle" "az" {
  input        = ["us-west-1a", "us-west-1c", "us-west-1d", "us-west-1e"]
  result_count = 2
}

resource "aws_elb" "example" {
  # Place the ELB in any two of the given availability zones, selected
  # at random.
  availability_zones = random_shuffle.az.result

  # ... and other aws_elb arguments ...
}

How to save an arbitary value in tf state ?​

Save the value as a variable and output the value as output.

terraform AWS main file example​

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 5.0"
    }
  }
}

# Configure the AWS Provider
provider "aws" {
  region = "us-east-1"
}

How move a resource inside a module using moved block​

> Step 1 : Initial Resource​

# ./lab-demo/s3.tf

resource "aws_s3_bucket" "moved_demo" {
  bucket = "moved-demo"
  tags = {
    env = "lab"
  }
}

> Step 2 : Create module, Move resource inside module and add moved block​

./modules/aws/s3/s3.tf

# ./modules/aws/s3/s3.tf

resource "aws_s3_bucket" "moved_demo" {
  bucket = "moved-demo"
  tags = {
    env = "lab"
  }
}

./lab-demo/s3.tf

./lab-demo/s3.tf

module "s3" {
  source = "./modules/aws/s3"
}

moved {
  from = aws_s3_bucket.moved_demo
  to   = module.s3.aws_s3_bucket.moved_demo
}

Run terraform plan it will not show any destroy operation. Run terraform apply when you are sure that terraform didn't show any destroy operation.

> Step 3 : Remove the moved block​

./modules/aws/s3/s3.tf

# ./modules/aws/s3/s3.tf

resource "aws_s3_bucket" "moved_demo" {
  bucket = "moved-demo"
  tags = {
    env = "lab"
  }
}

./lab-demo/s3.tf

./lab-demo/s3.tf

module "s3" {
  source = "./modules/aws/s3"
}

Ref: https://tanmay-bhat.github.io/posts/how-to-move-a-terraform-resource-into-a-module-using-moved-block/#:~:text=Move%20a%20Resource%20Into%20Module,demo%2Fs3.tf%20file.&text=Since%20we%20have%20the%20resource,demo%2Fmain.tf%20file.

Terraform sensitive information using sensitive variable​

variable "db_username" {
  description = "Database administrator username"
  type        = string
  sensitive   = true
}

How to unlock a locked state file​

terraform force-unlock -force LOCK_ID

Ref: https://stackoverflow.com/questions/65595852/terraform-statefile-is-locked-how-do-i-unlock-it