# Open SWE base AMI — ARM64 (Graviton) Ubuntu 24.04 LTS.
#
# Builds the immutable base image for the single EC2 instance per env
# (open-swe-dev / open-swe-prod) in seahaven-vpc. The image bakes the runtime
# (uv + Python 3.12, nginx, awscli v2, CloudWatch agent) and the service-user /
# systemd / nginx TEMPLATES. It bakes NO secrets and NO env-specific values —
# those are materialized at first boot by user-data + deploy/seahaven/fetch-config.sh
# (Secrets Manager + SSM -> root-only tmpfs .env, fail-fast).
#
# Build:  packer init . && packer build open-swe-base.pkr.hcl
# The resulting AMI id is pinned in infra/cdk.context.json (CDK cachedInContext:true);
# see README.md "AMI -> cdk.context.json pinning contract".

packer {
  required_version = ">= 1.11.0, < 2.0.0"
  required_plugins {
    amazon = {
      source  = "github.com/hashicorp/amazon"
      version = "1.3.6"
    }
  }
}

variable "aws_region" {
  type    = string
  default = "us-east-1"
}

variable "instance_type" {
  type    = string
  default = "t4g.medium" # ARM64 (Graviton) build host; runtime instances are ~t4g.large
}

variable "ami_name_prefix" {
  type    = string
  default = "open-swe-base-arm64"
}

# Versions baked into the image. Pin and bump deliberately.
variable "python_version" {
  type    = string
  default = "3.12"
}

variable "node_major" {
  type    = string
  default = "24"
}

variable "uv_version" {
  type    = string
  default = "0.11.24"
}

variable "cloudwatch_agent_deb_url" {
  type    = string
  default = "https://amazoncloudwatch-agent.s3.amazonaws.com/ubuntu/arm64/latest/amazon-cloudwatch-agent.deb"
}

variable "awscli_zip_url" {
  type    = string
  default = "https://awscli.amazonaws.com/awscli-exe-linux-aarch64.zip"
}

locals {
  timestamp = formatdate("YYYYMMDD-hhmmss", timestamp())
}

# Latest Canonical Ubuntu 24.04 (Noble) arm64 server image.
source "amazon-ebs" "open-swe" {
  region        = var.aws_region
  instance_type = var.instance_type
  ssh_username  = "ubuntu"

  ami_name        = "${var.ami_name_prefix}-${local.timestamp}"
  # ASCII only — AWS rejects non-ASCII in the AMI Description attribute.
  ami_description = "Open SWE base - Ubuntu 24.04 arm64 + uv/py3.12 + nginx + CW agent (templates only, no secrets)"

  source_ami_filter {
    filters = {
      name                = "ubuntu/images/hvm-ssd*/ubuntu-noble-24.04-arm64-server-*"
      architecture        = "arm64"
      root-device-type    = "ebs"
      virtualization-type = "hvm"
    }
    owners      = ["099720109477"] # Canonical
    most_recent = true
  }

  # IMDSv2 required on the build host.
  metadata_options {
    http_endpoint               = "enabled"
    http_tokens                 = "required"
    http_put_response_hop_limit = 1
  }

  # gp3 root, encrypted. Runtime root size is set by CDK; this is just the build host.
  launch_block_device_mappings {
    device_name           = "/dev/sda1"
    volume_size           = 20
    volume_type           = "gp3"
    encrypted             = true
    delete_on_termination = true
  }

  tags = {
    Name      = "open-swe-base-arm64"
    Purpose   = "open-swe-runtime-base"
    ManagedBy = "packer"
  }
}

build {
  name    = "open-swe-base"
  sources = ["source.amazon-ebs.open-swe"]

  # Stage the boot-time templates into the image. The destination dir must exist
  # BEFORE a trailing-slash (contents-only) file upload — packer's file provisioner
  # does not create it, and uploading the directory itself trips scp ("Is a
  # directory"). So mkdir first, then upload the contents into it.
  provisioner "shell" {
    inline = ["mkdir -p /tmp/open-swe-templates"]
  }

  provisioner "file" {
    source      = "${path.root}/templates/"
    destination = "/tmp/open-swe-templates"
  }

  provisioner "shell" {
    environment_vars = [
      "PYTHON_VERSION=${var.python_version}",
      "NODE_MAJOR=${var.node_major}",
      "UV_VERSION=${var.uv_version}",
      "CLOUDWATCH_AGENT_DEB_URL=${var.cloudwatch_agent_deb_url}",
      "AWSCLI_ZIP_URL=${var.awscli_zip_url}",
    ]
    # {{ .Vars }} MUST be included or the environment_vars above never reach the
    # script (provision.sh runs under `set -u` and fails on the first reference).
    execute_command = "chmod +x {{ .Path }}; {{ .Vars }} sudo -E bash '{{ .Path }}'"
    script          = "${path.root}/scripts/provision.sh"
  }
}