iaas

name	iaas
description	Infrastructure as a Service cloud computing
license	MIT
compatibility	opencode
metadata	{"audience":"developer, devops-engineer","category":"devops"}

What I do

• Provision and manage cloud infrastructure (compute, storage, network)
• Configure virtual machines and networking
• Set up managed databases and storage services
• Implement identity and access management
• Configure security groups and firewall rules
• Optimize infrastructure costs and performance

When to use me

• When you need full control over infrastructure
• When migrating legacy applications
• When running custom or unsupported workloads
• When building lift-and-shift solutions
• When requiring dedicated hardware
• When implementing custom security requirements

Key Concepts

Virtual Machine Provisioning

# Terraform - AWS EC2
resource "aws_instance" "web" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t3.micro"
  subnet_id     = aws_subnet.public.id
  
  vpc_security_group_ids = [aws_security_group.web.id]
  
  tags = {
    Name        = "WebServer"
    Environment = "production"
  }
  
  root_block_device {
    volume_size = 20
    volume_type = "gp3"
    encrypted   = true
  }
}

# GCP Compute Engine
resource "google_compute_instance" "web" {
  name         = "web-server"
  machine_type = "e2-medium"
  zone         = "us-central1-a"
  
  boot_disk {
    initialize_params {
      image = "debian-11-bullseye-v20220719"
      size  = 20
    }
  }
  
  network_interface {
    network = "default"
    access_config {
      // Ephemeral IP
    }
  }
}

# Azure VM
resource "azurerm_virtual_machine" "web" {
  name                  = "web-server"
  location              = "eastus"
  resource_group_name   = azurerm_resource_group.main.name
  vm_size               = "Standard_B1s"
  
  storage_os_disk {
    name              = "osdisk"
    managed_disk_type = "Standard_LRS"
    disk_size_gb      = 30
  }
  
  os_profile {
    computer_name  = "webserver"
    admin_username = "admin"
  }
  
  os_profile_linux_config {
    disable_password_authentication = true
  }
}

Networking

# VPC with subnets
resource "aws_vpc" "main" {
  cidr_block           = "10.0.0.0/16"
  enable_dns_hostnames = true
  enable_dns_support   = true
}

resource "aws_subnet" "public" {
  vpc_id                  = aws_vpc.main.id
  cidr_block              = "10.0.1.0/24"
  map_public_ip_on_launch = true
  
  tags = {
    Type = "Public"
  }
}

resource "aws_subnet" "private" {
  vpc_id     = aws_vpc.main.id
  cidr_block = "10.0.2.0/24"
  
  tags = {
    Type = "Private"
  }
}

# Internet Gateway
resource "aws_internet_gateway" "main" {
  vpc_id = aws_vpc.main.id
  
  tags = {
    Name = "Main IGW"
  }
}

Managed Databases

# RDS PostgreSQL
resource "aws_db_instance" "postgres" {
  identifier             = "mydb"
  engine                 = "postgres"
  engine_version         = "15.3"
  instance_class         = "db.t3.micro"
  
  allocated_storage     = 20
  max_allocated_storage = 100
  
  db_name  = "mydb"
  username = "dbadmin"
  password = var.db_password
  
  vpc_security_group_ids = [aws_security_group.rds.id]
  db_subnet_group_name   = aws_db_subnet_group.main.name
  
  backup_retention_period = 7
  skip_final_snapshot     = false
  final_snapshot_identifier = "mydb-final"
  
  enabled_cloudwatch_logs_exports = ["postgresql", "upgrade"]
}

IaaS vs PaaS vs SaaS

Layer	Responsibility	Examples
IaaS	Compute, storage, networking	EC2, GCE, Azure VMs
IaaS	OS, middleware, runtime	App Service, Cloud Run
SaaS	Complete application	Gmail, Office 365

Scaling Options

# Auto Scaling Group
resource "aws_autoscaling_group" "web" {
  name                = "web-asg"
  vpc_zone_identifier = [aws_subnet.public.id]
  
  desired_capacity = 2
  max_size         = 10
  min_size         = 2
  
  launch_template {
    id      = aws_launch_template.web.id
    version = "$Latest"
  }
  
  tag {
    key                 = "Name"
    value               = "web-asg"
    propagate_at_launch = true
  }
}

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

Security Considerations

• Use IAM roles, not access keys
• Enable encryption at rest
• Configure network ACLs
• Implement VPC flow logs
• Regular patching and updates
• Use Bastion hosts for access