Revamp Academy Docs

Project architecture

VPC
 │
 ├── Public Subnet-1 ── EC2-1
 ├── Public Subnet-2 ── EC2-2
 ├── Internet Gateway
 └── Route Table (0.0.0.0/0 → IGW)

Complete starter configuration

A single-subnet version you can apply and then expand:

resource "aws_vpc" "main" {
  cidr_block           = "10.10.0.0/16"
  enable_dns_hostnames = true
 
  tags = {
    Name = "terraform-vpc"
  }
}
 
resource "aws_subnet" "public" {
  vpc_id                  = aws_vpc.main.id
  cidr_block              = "10.10.1.0/24"
  availability_zone       = "ap-south-1a"
  map_public_ip_on_launch = true
 
  tags = {
    Name = "public-subnet"
  }
}
 
resource "aws_internet_gateway" "igw" {
  vpc_id = aws_vpc.main.id
 
  tags = {
    Name = "main-igw"
  }
}
 
resource "aws_route_table" "public_rt" {
  vpc_id = aws_vpc.main.id
 
  route {
    cidr_block = "0.0.0.0/0"
    gateway_id = aws_internet_gateway.igw.id
  }
 
  tags = {
    Name = "public-route-table"
  }
}
 
resource "aws_route_table_association" "public_assoc" {
  subnet_id      = aws_subnet.public.id
  route_table_id = aws_route_table.public_rt.id
}
 
resource "aws_security_group" "web_sg" {
  name        = "web-sg"
  description = "Allow SSH and HTTP"
  vpc_id      = aws_vpc.main.id
 
  ingress {
    description = "SSH"
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
 
  ingress {
    description = "HTTP"
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
 
  ingress {
    description = "HTTPS"
    from_port   = 443
    to_port     = 443
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
 
  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }
}
 
resource "aws_instance" "web" {
  ami                    = "ami-07a00cf47dbbc844c"
  instance_type          = "t3.micro"
  subnet_id              = aws_subnet.public.id
  vpc_security_group_ids = [aws_security_group.web_sg.id]
 
  tags = {
    Name = "terraform-ec2"
  }
}

Opening SSH (22) to 0.0.0.0/0 is fine for short labs. Lock it to your IP (or remove it) for anything longer-lived.

Two-subnet walkthrough

1. VPC

resource "aws_vpc" "myvpc" {
  cidr_block = var.cidr
}

2–3. Public subnets

resource "aws_subnet" "sub1" {
  vpc_id                  = aws_vpc.myvpc.id
  cidr_block              = "10.0.0.0/24"
  availability_zone       = "ap-south-1a"
  map_public_ip_on_launch = true
}
 
resource "aws_subnet" "sub2" {
  vpc_id                  = aws_vpc.myvpc.id
  cidr_block              = "10.0.1.0/24"
  availability_zone       = "ap-south-1b"
  map_public_ip_on_launch = true
}

4. Internet gateway

resource "aws_internet_gateway" "igw" {
  vpc_id = aws_vpc.myvpc.id
}

5. Route table

resource "aws_route_table" "RT" {
  vpc_id = aws_vpc.myvpc.id
 
  route {
    cidr_block = "0.0.0.0/0"
    gateway_id = aws_internet_gateway.igw.id
  }
}

6. Associations

resource "aws_route_table_association" "rta1" {
  subnet_id      = aws_subnet.sub1.id
  route_table_id = aws_route_table.RT.id
}
 
resource "aws_route_table_association" "rta2" {
  subnet_id      = aws_subnet.sub2.id
  route_table_id = aws_route_table.RT.id
}

7. Security group

Allow SSH (22) and HTTP (80) on a group attached to the VPC.

8–9. EC2 instances

resource "aws_instance" "webserver1" {
  ami           = "ami-0db56f446d44f2f09"
  instance_type = "t3.micro"
  subnet_id     = aws_subnet.sub1.id
}
 
resource "aws_instance" "webserver2" {
  ami           = "ami-0db56f446d44f2f09"
  instance_type = "t3.micro"
  subnet_id     = aws_subnet.sub2.id
}

10. Outputs

output "server1_public_ip" {
  value = aws_instance.webserver1.public_ip
}
 
output "server2_public_ip" {
  value = aws_instance.webserver2.public_ip
}

Replace AMI IDs with current ones for your region (ap-south-1 in these examples). Attach the security group and a key pair if you need SSH access.

Hands-on project

Create:

1 VPC
  ↓
2 Public Subnets
  ↓
1 Internet Gateway
  ↓
1 Route Table (+ associations)
  ↓
1 Security Group
  ↓
2 EC2 Instances

Day 2 assignment

Create:

1 VPC
3 public subnets
1 internet gateway
1 route table
1 security group
3 EC2 instances

Display as outputs:

VPC ID
Subnet IDs
Public IPs

Clean up

terraform destroy

Day 2 summary

Provider configuration
        ↓
Multiple providers / regions
        ↓
Variables + terraform.tfvars
        ↓
Outputs
        ↓
Interpolation & references
        ↓
VPC → Subnet → IGW → Route table → SG → EC2

Project architecture

VPC
 │
 ├── Public Subnet-1 ── EC2-1
 ├── Public Subnet-2 ── EC2-2
 ├── Internet Gateway
 └── Route Table (0.0.0.0/0 → IGW)

Complete starter configuration

A single-subnet version you can apply and then expand:

resource "aws_vpc" "main" {
  cidr_block           = "10.10.0.0/16"
  enable_dns_hostnames = true
 
  tags = {
    Name = "terraform-vpc"
  }
}
 
resource "aws_subnet" "public" {
  vpc_id                  = aws_vpc.main.id
  cidr_block              = "10.10.1.0/24"
  availability_zone       = "ap-south-1a"
  map_public_ip_on_launch = true
 
  tags = {
    Name = "public-subnet"
  }
}
 
resource "aws_internet_gateway" "igw" {
  vpc_id = aws_vpc.main.id
 
  tags = {
    Name = "main-igw"
  }
}
 
resource "aws_route_table" "public_rt" {
  vpc_id = aws_vpc.main.id
 
  route {
    cidr_block = "0.0.0.0/0"
    gateway_id = aws_internet_gateway.igw.id
  }
 
  tags = {
    Name = "public-route-table"
  }
}
 
resource "aws_route_table_association" "public_assoc" {
  subnet_id      = aws_subnet.public.id
  route_table_id = aws_route_table.public_rt.id
}
 
resource "aws_security_group" "web_sg" {
  name        = "web-sg"
  description = "Allow SSH and HTTP"
  vpc_id      = aws_vpc.main.id
 
  ingress {
    description = "SSH"
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
 
  ingress {
    description = "HTTP"
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
 
  ingress {
    description = "HTTPS"
    from_port   = 443
    to_port     = 443
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
 
  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }
}
 
resource "aws_instance" "web" {
  ami                    = "ami-07a00cf47dbbc844c"
  instance_type          = "t3.micro"
  subnet_id              = aws_subnet.public.id
  vpc_security_group_ids = [aws_security_group.web_sg.id]
 
  tags = {
    Name = "terraform-ec2"
  }
}

Opening SSH (22) to 0.0.0.0/0 is fine for short labs. Lock it to your IP (or remove it) for anything longer-lived.

Two-subnet walkthrough

1. VPC

resource "aws_vpc" "myvpc" {
  cidr_block = var.cidr
}

2–3. Public subnets

resource "aws_subnet" "sub1" {
  vpc_id                  = aws_vpc.myvpc.id
  cidr_block              = "10.0.0.0/24"
  availability_zone       = "ap-south-1a"
  map_public_ip_on_launch = true
}
 
resource "aws_subnet" "sub2" {
  vpc_id                  = aws_vpc.myvpc.id
  cidr_block              = "10.0.1.0/24"
  availability_zone       = "ap-south-1b"
  map_public_ip_on_launch = true
}

4. Internet gateway

resource "aws_internet_gateway" "igw" {
  vpc_id = aws_vpc.myvpc.id
}

5. Route table

resource "aws_route_table" "RT" {
  vpc_id = aws_vpc.myvpc.id
 
  route {
    cidr_block = "0.0.0.0/0"
    gateway_id = aws_internet_gateway.igw.id
  }
}

6. Associations

resource "aws_route_table_association" "rta1" {
  subnet_id      = aws_subnet.sub1.id
  route_table_id = aws_route_table.RT.id
}
 
resource "aws_route_table_association" "rta2" {
  subnet_id      = aws_subnet.sub2.id
  route_table_id = aws_route_table.RT.id
}

7. Security group

Allow SSH (22) and HTTP (80) on a group attached to the VPC.

8–9. EC2 instances

resource "aws_instance" "webserver1" {
  ami           = "ami-0db56f446d44f2f09"
  instance_type = "t3.micro"
  subnet_id     = aws_subnet.sub1.id
}
 
resource "aws_instance" "webserver2" {
  ami           = "ami-0db56f446d44f2f09"
  instance_type = "t3.micro"
  subnet_id     = aws_subnet.sub2.id
}

10. Outputs

output "server1_public_ip" {
  value = aws_instance.webserver1.public_ip
}
 
output "server2_public_ip" {
  value = aws_instance.webserver2.public_ip
}

Replace AMI IDs with current ones for your region (ap-south-1 in these examples). Attach the security group and a key pair if you need SSH access.

Hands-on project

Create:

1 VPC
  ↓
2 Public Subnets
  ↓
1 Internet Gateway
  ↓
1 Route Table (+ associations)
  ↓
1 Security Group
  ↓
2 EC2 Instances

Day 2 assignment

Create:

1 VPC
3 public subnets
1 internet gateway
1 route table
1 security group
3 EC2 instances

Display as outputs:

VPC ID
Subnet IDs
Public IPs

Clean up

terraform destroy

Day 2 summary

Provider configuration
        ↓
Multiple providers / regions
        ↓
Variables + terraform.tfvars
        ↓
Outputs
        ↓
Interpolation & references
        ↓
VPC → Subnet → IGW → Route table → SG → EC2

AWS Infrastructure Project

Project architecture

Complete starter configuration

Two-subnet walkthrough

1. VPC

2–3. Public subnets

4. Internet gateway

5. Route table

6. Associations

7. Security group

8–9. EC2 instances

10. Outputs

Hands-on project

Day 2 assignment

Clean up

Day 2 summary

AWS Infrastructure Project

Project architecture

Complete starter configuration

Two-subnet walkthrough

1. VPC

2–3. Public subnets

4. Internet gateway

5. Route table

6. Associations

7. Security group

8–9. EC2 instances

10. Outputs

Hands-on project

Day 2 assignment

Clean up

Day 2 summary