LAB: Terraform Workflow + Import (Production Style)

1. Create an AWS resource manually (outside Terraform)
2. Import it into Terraform state
3. Manage it fully using Terraform

---

📁 Project Structure (IMPORTANT)

terraform-import-lab/
│
├── provider.tf
├── variables.tf
├── terraform.tfvars
├── main.tf
├── outputs.tf
│
└── README.md

---

🧠 Concept

🔹 What is Terraform Import?

Terraform import is used when:

• Resource already exists in AWS
• But Terraform DOES NOT manage it yet

👉 We "attach" Terraform to existing infrastructure

---

🚀 STEP 1 — Create Resource Manually (AWS Console)

Students MUST create manually:

Create S3 Bucket:

• Go to AWS Console
• Create S3 bucket
• Give unique name (example):

my-import-lab-<yourname>-123

⚠️ Save the bucket name — you will use it later

---

📄 provider.tf

provider "aws" {
  region = var.aws_region
}

---

📄 variables.tf

variable "aws_region" {
  description = "AWS region"
  type        = string
}

variable "bucket_name" {
  description = "Existing S3 bucket name"
  type        = string
}

---

📄 terraform.tfvars

👉 fill this manually

aws_region  = "us-east-2"
bucket_name = "REPLACE_WITH_YOUR_BUCKET_NAME"

---

📄 main.tf

⚠️ IMPORTANT: This must match existing resource

resource "aws_s3_bucket" "existing" {
  bucket = var.bucket_name

  tags = {
    ManagedBy = "Terraform"
    Project   = "ImportLab"
  }
}

---

📄 outputs.tf

output "bucket_name" {
  value = aws_s3_bucket.existing.bucket
}

---

📄 README.md (for students)

Terraform Import Lab

Steps:

1. terraform init

2. terraform plan
   (Expected: Terraform wants to CREATE bucket — BUT DON'T APPLY)

3. Import existing resource:
   terraform import aws_s3_bucket.existing <bucket_name>

4. Run:
   terraform plan

   (Expected: NO changes)

5. Modify tags in main.tf

6. Run:
   terraform apply

---

⚙️ STEP 2 — Initialize Terraform

terraform init

---

⚙️ STEP 3 — Plan (IMPORTANT MOMENT)

terraform plan

👉 You will see:

+ create aws_s3_bucket

⚠️ THIS IS WRONG (resource already exists)

---

🔥 STEP 4 — Import Resource

terraform import aws_s3_bucket.existing <your-bucket-name>

Example:

terraform import aws_s3_bucket.existing my-import-lab-aisal-123

---

⚙️ STEP 5 — Plan Again

terraform plan

✅ Expected:

No changes. Infrastructure is up-to-date.

---

🎯 STEP 6 — Modify Resource (Real DevOps Scenario)

Update main.tf:

tags = {
  ManagedBy = "Terraform"
  Project   = "ImportLab"
  Owner     = "Student"
}

---

⚙️ STEP 7 — Apply Changes

terraform apply

✅ Now Terraform manages the resource

---

1. Terraform Workflow

• init → setup
• plan → preview
• apply → execute

---

2. Import Concept

Before import:

• Terraform wants to CREATE resource ❌

After import:

• Terraform recognizes existing resource ✅

---

3. State File Role

👉 Import updates terraform.tfstate

---

4. Real DevOps Scenario

Used when:

• Company already has infrastructure
• You start using Terraform later

---

🚨 Common Mistakes (Teach Them)

❌ Wrong resource name

aws_s3_bucket.wrong_name

❌ Wrong bucket name

❌ Skipping import and running apply

👉 This will FAIL

---

👉 Import IAM user

resource "aws_iam_user" "example" {
  name = var.user_name
}

Command:

terraform import aws_iam_user.example <username>

---

🧩 Interview Questions (from this lab)

1. What is terraform import?
2. Does import create resource?
3. What happens if configuration doesn’t match?
4. Can Terraform import automatically generate code?
5. Where is imported data stored?

---

💡 Real Production Insight

In real companies:

• 80% infra exists BEFORE Terraform
• Import is used during Terraform adoption phase

Comments

[vandana.platform]

Great hands-on lab. This teaches one of the most important real-world Terraform skills: adopting existing infrastructure safely instead of rebuilding it blindly. The step where plan shows a create before import is especially valuable because that is exactly where many teams make mistakes in production. Clean, practical, and very useful for anyone learning true Terraform workflow beyond just init/plan/apply.