Terraform init for initialization - Commands & Configuration

Introduction

Terraform init prepares your working folder to use Terraform. It downloads necessary plugins and sets up the backend so you can start managing infrastructure.

When you start a new Terraform project and need to set up the environment.

When you clone an existing Terraform project and want to download required providers.

When you change the backend configuration to store state remotely.

When you add new provider plugins to your Terraform configuration.

When you upgrade Terraform version and want to refresh the setup.

Config File - main.tf

main.tf

terraform {
  required_version = ">= 1.5.0"
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 4.0"
    }
  }
  backend "local" {}
}

provider "aws" {
  region = "us-east-1"
}

resource "aws_s3_bucket" "example" {
  bucket = "example-terraform-bucket-12345"
  acl    = "private"
}

This file sets the Terraform version and AWS provider requirements.

The backend "local" {} means Terraform state is stored on your computer.

The provider "aws" block configures AWS region.

The resource "aws_s3_bucket" block creates an S3 bucket named "example-terraform-bucket-12345".

Commands

This command initializes the Terraform working directory. It downloads the AWS provider plugin and sets up the backend for state management.

Terminal

terraform init

Expected Output

Initializing the backend...



Initializing provider plugins...

- Finding hashicorp/aws versions matching "~> 4.0"...

- Installing hashicorp/aws v4.70.0...

- Installed hashicorp/aws v4.70.0 (signed by HashiCorp)



Terraform has been successfully initialized!



You may now begin working with Terraform. Try running "terraform plan" to see

any changes that are required for your infrastructure. All Terraform commands

should now work.



If you ever set or change modules or backend configuration for Terraform,

you must run "terraform init" again.

This command shows what Terraform will do when applying the configuration. It helps verify the setup after initialization.

Terminal

terraform plan

Expected Output

Refreshing Terraform state in-memory prior to plan...



An execution plan has been generated and is shown below.

Resource actions are indicated with the following symbols:

  + create



Terraform will perform the following actions:



  # aws_s3_bucket.example will be created

  + resource "aws_s3_bucket" "example" {

      + acl                         = "private"

      + bucket                      = "example-terraform-bucket-12345"

      + force_destroy               = false

      + id                          = (known after apply)

      + tags                        = (known after apply)

    }



Plan: 1 to add, 0 to change, 0 to destroy.



─────────────────────────────────────────────────────────────────────────────



Note: You didn't specify an "-out" parameter to save this plan, so Terraform

can't guarantee to take exactly these actions if you run "terraform apply".

Key Concept

If you remember nothing else from this pattern, remember: terraform init sets up your project by downloading providers and configuring state storage so Terraform can manage your infrastructure.

Common Mistakes

Running terraform plan or apply before terraform init

Terraform needs initialization to download providers and configure backend; without it, commands fail.

Always run terraform init first to prepare the working directory.

Not running terraform init after changing backend or provider versions

Changes require re-initialization to update plugins and backend settings.

Run terraform init again whenever you change backend or provider configurations.

Summary

terraform init downloads provider plugins and sets up backend state storage.

Run terraform init first before any other Terraform commands.

terraform plan shows what changes Terraform will make based on your configuration.