Infraestrutura Imutável

source "amazon-ebs" "app" {
  ami_name      = "app-{{timestamp}}"
  instance_type = "t3.small"
  region        = "us-east-1"
  source_ami_filter {
    filters = {
      name = "ubuntu/images/*ubuntu-jammy-22.04-amd64-server-*"
    }
    most_recent = true
    owners      = ["099720109477"]
  }
  ssh_username = "ubuntu"
}

build {
  sources = ["source.amazon-ebs.app"]

  provisioner "shell" {
    scripts = ["scripts/install_deps.sh"]
  }
}

resource "aws_launch_template" "app" {
  name_prefix   = "app-"
  image_id      = var.ami_id  # New AMI for each release
  instance_type = "t3.small"

  lifecycle {
    create_before_destroy = true
  }
}

# ASG automatically replaces instances with new AMI
resource "aws_autoscaling_group" "app" {
  launch_template {
    id      = aws_launch_template.app.id
    version = "$Latest"
  }
  instance_refresh {
    strategy = "Rolling"
  }
}