⚙️ Core Workflow Commands

Terraform Workflow Overview

┌─────────────────────────────────────────────────────────────┐
│              Terraform Core Workflow                        │
└─────────────────────────────────────────────────────────────┘

  WRITE → INIT → PLAN → APPLY → DESTROY (optional)
    ↓       ↓      ↓       ↓         ↓
  .tf    Download Preview Execute  Remove
  files  providers changes changes  resources

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1. terraform init

Purpose: Initialize a Terraform working directory.

What it does:

• Downloads provider plugins
• Initializes backend configuration
• Downloads modules
• Creates .terraform directory
• Creates or updates .terraform.lock.hcl

Basic Usage

# Initialize current directory
terraform init

Common Options

# Upgrade providers to latest allowed version
terraform init -upgrade

# Reconfigure backend (ignore existing state)
terraform init -reconfigure

# Migrate state from one backend to another
terraform init -migrate-state

# Skip backend initialization
terraform init -backend=false

Example Output

Initializing the backend...
Initializing provider plugins...
- Finding hashicorp/aws versions matching "~> 5.0"...
- Installing hashicorp/aws v5.31.0...
- Installed hashicorp/aws v5.31.0

Terraform has been successfully initialized!

Directory Structure After Init

project/
├── .terraform/           # Created by init
│   └── providers/        # Downloaded providers
├── .terraform.lock.hcl   # Provider version lock file
├── main.tf
└── variables.tf

---

2. terraform plan

Purpose: Preview changes before applying them.

What it shows:

• Resources to be created (+)
• Resources to be modified (~)
• Resources to be destroyed (-)
• Resources to be replaced (-/+)

Basic Usage

# Preview changes
terraform plan

# Save plan to file
terraform plan -out=tfplan

# Show detailed changes
terraform plan -detailed-exitcode

Example Plan Output

Terraform will perform the following actions:

  # aws_instance.web will be created
  + resource "aws_instance" "web" {
      + ami           = "ami-0c55b159cbfafe1f0"
      + instance_type = "t2.micro"
      + id            = (known after apply)
      + public_ip     = (known after apply)
    }

  # aws_security_group.web will be modified
  ~ resource "aws_security_group" "web" {
      ~ ingress {
          + cidr_blocks = ["0.0.0.0/0"]
        }
    }

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

Plan Symbols

Symbol	Meaning
+	Resource will be created
-	Resource will be destroyed
~	Resource will be modified in-place
-/+	Resource will be destroyed and recreated
<=	Resource will be read during apply

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3. terraform apply

Purpose: Execute the planned changes.

Basic Usage

# Apply with confirmation prompt
terraform apply

# Apply without confirmation (CI/CD)
terraform apply -auto-approve

# Apply a saved plan
terraform apply tfplan

# Apply with variable override
terraform apply -var="instance_count=5"