Infrastructure as Code, Automation & Cloud Architecture

# AWS Infrastructure as Code
# Generated by DevOps Portfolio Terraform Generator

provider "aws" {
  region = "us-west-2"
}

resource "aws_vpc" "main" {
  cidr_block = "10.0.0.0/16"
  
  tags = {
    Name = "main-vpc"
    Environment = "production"
  }
}

resource "aws_subnet" "public" {
  count = 2

  vpc_id            = aws_vpc.main.id
  cidr_block        = "10.0.${count.index}.0/24"
  availability_zone = "us-west-2${["a", "b"][count.index]}"
  tags = {
    Name = "public-subnet-${count.index}"
  }
}

resource "aws_security_group" "web" {
  name        = "web-sg"
  description = "Allow web traffic"
  vpc_id      = aws_vpc.main.id

  ingress {
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
  
  ingress {
    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" {
  count = 2
  
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t3.micro"
  subnet_id     = aws_subnet.public[${count.index % 2}].id
  
  vpc_security_group_ids = [aws_security_group.web.id]
  
  tags = {
    Name = "web-server-${count.index}"
  }
  
  user_data = <<-EOF
              #!/bin/bash
              echo "Hello from Terraform!"
              yum update -y
              yum install -y httpd
              systemctl start httpd
              systemctl enable httpd
              echo "<h1>Deployed with Terraform</h1>" > /var/www/html/index.html
              EOF
}


resource "aws_lb" "web" {
  name               = "web-lb"
  internal           = false
  load_balancer_type = "application"
  security_groups    = [aws_security_group.web.id]
  subnets            = aws_subnet.public[*].id
}

resource "aws_lb_target_group" "web" {
  name     = "web-target-group"
  port     = 80
  protocol = "HTTP"
  vpc_id   = aws_vpc.main.id
  
  health_check {
    path                = "/"
    port                = "traffic-port"
    healthy_threshold   = 3
    unhealthy_threshold = 3
    timeout             = 5
    interval            = 30
  }
}

resource "aws_lb_listener" "web" {
  load_balancer_arn = aws_lb.web.arn
  port              = 80
  protocol          = "HTTP"
  
  default_action {
    type             = "forward"
    target_group_arn = aws_lb_target_group.web.arn
  }
}

resource "aws_lb_target_group_attachment" "web" {
  count            = 2
  target_group_arn = aws_lb_target_group.web.arn
  target_id        = aws_instance.web[count.index].id
  port             = 80
}


resource "aws_launch_template" "web" {
  name_prefix   = "web-"
  image_id      = "ami-0c55b159cbfafe1f0"
  instance_type = "t3.micro"
  
  vpc_security_group_ids = [aws_security_group.web.id]
  
  user_data = base64encode(<<-EOF
              #!/bin/bash
              echo "Hello from Terraform!"
              yum update -y
              yum install -y httpd
              systemctl start httpd
              systemctl enable httpd
              echo "<h1>Deployed with Terraform</h1>" > /var/www/html/index.html
              EOF
  )
}

resource "aws_autoscaling_group" "web" {
  desired_capacity    = 2
  max_size            = 4
  min_size            = 1
  vpc_zone_identifier = aws_subnet.public[*].id
  
  launch_template {
    id      = aws_launch_template.web.id
    version = "$Latest"
  }
  
  tag {
    key                 = "Name"
    value               = "web-server-asg"
    propagate_at_launch = true
  }
}

resource "aws_autoscaling_attachment" "web" {
  autoscaling_group_name = aws_autoscaling_group.web.name
  lb_target_group_arn    = aws_lb_target_group.web.arn
}

resource "aws_autoscaling_policy" "scale_up" {
  name                   = "scale-up"
  autoscaling_group_name = aws_autoscaling_group.web.name
  adjustment_type        = "ChangeInCapacity"
  scaling_adjustment     = 1
  cooldown               = 300
}

resource "aws_autoscaling_policy" "scale_down" {
  name                   = "scale-down"
  autoscaling_group_name = aws_autoscaling_group.web.name
  adjustment_type        = "ChangeInCapacity"
  scaling_adjustment     = -1
  cooldown               = 300
}

resource "aws_cloudwatch_metric_alarm" "high_cpu" {
  alarm_name          = "high-cpu-utilization"
  comparison_operator = "GreaterThanThreshold"
  evaluation_periods  = 2
  metric_name         = "CPUUtilization"
  namespace           = "AWS/EC2"
  period              = 120
  statistic           = "Average"
  threshold           = 80
  alarm_description   = "This metric monitors ec2 cpu utilization"
  alarm_actions       = [aws_autoscaling_policy.scale_up.arn]
  dimensions = {
    AutoScalingGroupName = aws_autoscaling_group.web.name
  }
}

resource "aws_cloudwatch_metric_alarm" "low_cpu" {
  alarm_name          = "low-cpu-utilization"
  comparison_operator = "LessThanThreshold"
  evaluation_periods  = 2
  metric_name         = "CPUUtilization"
  namespace           = "AWS/EC2"
  period              = 120
  statistic           = "Average"
  threshold           = 20
  alarm_description   = "This metric monitors ec2 cpu utilization"
  alarm_actions       = [aws_autoscaling_policy.scale_down.arn]
  dimensions = {
    AutoScalingGroupName = aws_autoscaling_group.web.name
  }
}

output "instance_ips" {
  value = aws_instance.web[*].public_ip
}


output "load_balancer_dns" {
  value = aws_lb.web.dns_name
}