Feature/apply workspaces

.github/workflows/ci.yml

@@ -3,10 +3,6 @@ name: Terraform CI
 on:
   pull_request:
     branches: [ main ]
-    paths:
-      - '**/*.tf'
-      - '**/*.tfvars'
-      - 'modules/**'
 
 jobs:
   validate:

README.md

@@ -7,7 +7,7 @@ It creates a Virtual Private Cloud (VPC) with public and private subnets, Intern
 
 ## 📘 Overview
 
-Infrastructure Includes
+### Infrastructure Includes
 
 - VPC (aws_vpc.csye6225)
 - 3 Public subnets and 3 Private subnets, each in a different AZ
@@ -16,69 +16,97 @@ Infrastructure Includes
 - Private Route Table (internal routing only)
 - Modular Terraform structure (separate .tf files for each resource type)
 
-Key Features
+### Key Features
+
 - Modular, readable configuration
 - Supports multiple environments (dev, demo) via separate .tfvars files
+- Terraform Workspaces to isolate states
 - No hardcoded values — variables and inputs are fully parameterized
 
 ---
 
-## 🗂️ Project Structure
-
-.
-├── main.tf
-├── providers.tf
-├── versions.tf
-├── variables.tf
-├── dev.tfvars              # dev environment variables
-├── demo.tfvars             # demo environment variables
-├── vpc.tf
-├── subnets.tf
-├── igw.tf
-├── route_tables.tf
-└── outputs.tf
-
----
-
-⚙️ Prerequisites
+## ⚙️ Prerequisites
 
 - Terraform >= 1.6.0
 - AWS CLI installed and configured
 
-```shell
-  aws configure --profile dev
-  aws configure --profile demo
-```
+  ```shell
+    aws configure --profile dev
+    aws configure --profile demo
+  ```
 
 - IAM user or profile with permissions to create VPC, subnets, route tables, and IGWs
+- Create environment-specific variable files (dev.tfvars or demo.tfvars) with the following structure:
+
+  ```hcl
+    region   = "us-east-1"
+    profile  = "dev"
+    vpc_name = "dev"
+    vpc_cidr = "10.0.0.0/16"
+  ```
 
 ---
 
-## 🚀 How to Deploy
+## 🚀 How to Deploy (with Terraform Workspaces)
+
+Workspaces let you maintain multiple, isolated sets of infrastructure (states)
+using the same code and resource names — ideal for creating multiple VPCs in one account/region.
 
-### Initialize Terraform
+### Step 1 - Initialize Terraform
 
 ```shell
 terraform init
 ```
 
-### Plan and Apply for Each Environment
+### Step 2 - Create and List Workspaces
+
+```shell
+terraform workspace new dev
+terraform workspace new demo
+terraform workspace list
+```
+
+You’ll see something like:
+
+```
+  default
+* dev
+  demo
+```
+
+The * indicates your current workspace
+
+### Step 3 - Plan and Apply for Each Environment
 
 - Dev Environment
 
   ```shell
-  terraform plan  -var-file="dev.tfvars"
-  terraform apply -var-file="dev.tfvars"
+  terraform workspace select dev
+  terraform plan  --var-file="dev.tfvars"
+  terraform apply --var-file="dev.tfvars"
   ```
 
 - Demo Environment
 
   ```shell
-  terraform plan  -var-file="demo.tfvars"
-  terraform apply -var-file="demo.tfvars"
+  terraform workspace select demo
+  terraform plan  --var-file="demo.tfvars"
+  terraform apply --var-file="demo.tfvars"
   ```
 
-### ⚠️ Important Notes:
+Terraform will automatically create per-workspace state files under:
+
+```
+terraform.tfstate.d/
+├── dev/
+│   └── terraform.tfstate
+└── demo/
+    └── terraform.tfstate
+```
+
+### ⚠️ Important Notes
+
+😁 This won't happen if you're using workspace!!
 
 - Each .tfvars represents a separate environment configuration.
 - Terraform treats all resources defined in this directory as a single state.
@@ -90,6 +118,7 @@ terraform init
 
 After deployment, Terraform prints key identifiers:
 
+- current_workspace
 - vpc_id
 - public_subnets
 - private_subnets
@@ -102,24 +131,17 @@ You can also view them via: `terraform output`
 
 ## 🧠 Notes
 
-- Each .tfvars defines values like:
-
-```hcl
-  region   = "us-east-1"
-  profile  = "dev"
-  vpc_name = "dev"
-  vpc_cidr = "10.0.0.0/16"
-```
-
-- Do not use multiple tfvars with the same workspace — Terraform will treat it as an update, not a new VPC.
-- For multiple coexisting VPCs in the same AWS account/region, consider switching to Terraform Workspaces (see next version).
+- Keep your CIDR blocks unique across workspaces (10.0.0.0/16, 10.1.0.0/16, etc.)
+- Add ${terraform.workspace} in resource tags to easily identify which workspace created which resource in AWS.
+- Terraform automatically stores workspace states in: `terraform.tfstate.d/<workspace>/terraform.tfstate`
 
 ---
 
 ## 🧹 Clean Up
 
-To destroy the infrastructure:
+To destroy the specific Workspace's infrastructure, select and destroy only that workspace's env
 
 ```shell
-terraform destroy -var-file="dev.tfvars"
+terraform workspace select demo
+terraform destroy -var-file="demo.tfvars"
 ```

igw.tf

@@ -3,6 +3,6 @@ resource "aws_internet_gateway" "csye6225" {
   vpc_id = aws_vpc.csye6225.id
 
   tags = merge(var.tags, {
-    Name = "igw-csye6225-${var.vpc_name}"
+    Name = "igw-csye6225-${var.vpc_name}-${terraform.workspace}"
   })
 }

outputs.tf

@@ -1,3 +1,7 @@
+output "current_workspace" {
+  value = terraform.workspace
+}
+
 output "vpc_id" {
   value = aws_vpc.csye6225.id
 }

providers.tf

@@ -1,5 +1,5 @@
 # Configure the AWS Provider
 provider "aws" {
-  region  = "us-east-1"
+  region  = var.region
   profile = var.profile
 }

route_tables.tf

@@ -3,7 +3,7 @@ resource "aws_route_table" "public" {
   vpc_id = aws_vpc.csye6225.id
 
   tags = merge(var.tags, {
-    Name = "rt-public-${var.vpc_name}"
+    Name = "rt-public-${var.vpc_name}-${terraform.workspace}"
   })
 }
 
@@ -12,7 +12,7 @@ resource "aws_route_table" "private" {
   vpc_id = aws_vpc.csye6225.id
 
   tags = merge(var.tags, {
-    Name = "rt-private-${var.vpc_name}"
+    Name = "rt-private-${var.vpc_name}-${terraform.workspace}"
   })
 }
 

subnets.tf

@@ -11,7 +11,7 @@ resource "aws_subnet" "public" {
   map_public_ip_on_launch = true
 
   tags = merge(var.tags, {
-    Name = "subnet-public-${var.vpc_name}-${each.key}",
+    Name = "subnet-public-${var.vpc_name}-${terraform.workspace}-${each.key}",
     Tier = "public"
   })
 }
@@ -28,7 +28,7 @@ resource "aws_subnet" "private" {
   availability_zone = each.key
 
   tags = merge(var.tags, {
-    Name = "subnet-private-${var.vpc_name}-${each.key}",
+    Name = "subnet-private-${var.vpc_name}-${terraform.workspace}-${each.key}",
     Tier = "private"
   })
 }

vpc.tf

@@ -1,11 +1,9 @@
 resource "aws_vpc" "csye6225" {
-  region               = var.region
   cidr_block           = var.vpc_cidr
   enable_dns_support   = true
   enable_dns_hostnames = true
 
   tags = merge(var.tags, {
-    Name = "csye6225-${var.vpc_name}"
+    Name = "csye6225-${var.vpc_name}-${terraform.workspace}"
   })
-
 }