locals {
  ############################ AWS configuration ############################

  # The AWS region where the Defguard infrastructure will be deployed.
  region = "eu-north-1"

  ############################ Core configuration ###########################

  # The URL for the Defguard Core. This is the URL under which the Defguard Core should be accessible.
  core_url = "https://defguard.example.com"

  # The gRPC port for the Defguard Core. This is the port that the core will use to communicate with Defguard Gateways.
  core_grpc_port = 50055

  # The HTTP port for the Defguard Core web UI. This is the port that the core will listen on for incoming HTTP requests.
  core_http_port = 8000

  # Whether to allow insecure cookies for the Defguard Core web UI. Set to true if you
  # are using HTTP to access the Defguard Core web UI.
  core_cookie_insecure = false

  # The initial password for the "admin" user. Use it to login to the Defguard Core web UI for the first time.
  default_admin_password = "pass123"

  # The deb package version of the Defguard Core that will be installed on the instance.
  # Must be a valid, released version of Defguard Core.
  core_package_version = "1.5.0"

  # The architecture of the Defguard Core server instance.
  # Supported values: "x86_64", "aarch64"
  core_arch = "x86_64"

  # The instance type for the Defguard Core server.
  core_instance_type = "t3.micro"

  ########################### Proxy configuration ###########################

  # The URL for the Defguard Proxy. This is the URL under which the Defguard Proxy should be accessible.
  proxy_url = "https://proxy.example.com"

  # The gRPC port for the Defguard Proxy. This is the port that the proxy will use to communicate with the Defguard Core.
  proxy_grpc_port = 50051

  # The HTTP port for the Defguard Proxy. This is the port that the proxy will listen on for incoming HTTP requests.
  proxy_http_port = 8000

  # The deb package version of the proxy that will be installed on the instance.
  # Must be a valid, released version of Defguard Proxy.
  proxy_package_version = "1.5.0"

  # The architecture of the Defguard Proxy server instance.
  # Supported values: "x86_64", "aarch64"
  proxy_arch = "x86_64"

  # The instance type for the Defguard Proxy server.
  proxy_instance_type = "t3.micro"

  ###################### VPN and Gateway configuration ######################

  # List of VPN networks to be created. A gateway will be created for each network.
  vpn_networks = [
    {
      # The ID of the VPN network. Must start with 1 and be incremented for each new network.
      # Used for modifying the network configuration later.
      id = 1
      # The name of the VPN network. Displayed to the users.
      name = "vpn1"
      # The CIDR address of the VPN network. Clients will be assigned IP addresses from this range.
      address = "10.10.10.1/24"
      # The UDP port for the WireGuard VPN. Gateways will listen on this port for incoming VPN connections.
      port = 51820
      # Whether to enable NAT for the VPN network. If true, the gateway will perform NAT (masquerade) for the VPN clients.
      # This is useful if you want the VPN clients to access the internet through the gateway or to access other resources in the VPC.
      nat = true
    }
  ]

  # The gateway deb package version that will be installed on the instance.
  # Must be a valid, released version of Defguard Gateway.
  gateway_package_version = "1.5.0"

  # The architecture of the Defguard Gateway server instance.
  # Supported values: "x86_64", "aarch64"
  gateway_arch = "x86_64"

  # The instance type for the Defguard Gateway server.
  gateway_instance_type = "t3.micro"

  ########################## Database configuration #########################

  # The name of the database that will be created for the Defguard Core.
  db_name = "defguard"

  # The username for the database that will be created for the Defguard Core.
  db_username = "defguard"

  # The port on which the database will listen for incoming connections.
  db_port = 5432

  # The password for the database user. This will be used by the Defguard Core to connect to the database.
  db_password = "defguard"

  # The amount of storage allocated for the database in GB. The minimum amount for this example required by AWS is 20 GB.
  db_storage = 20 # GB

  # The instance class for the database. This defines the performance characteristics of the database instance.
  db_instance_class = "db.t3.micro"

  ############################ VPC configuration ############################

  # The name of the VPC that will be created for the Defguard infrastructure.
  vpc_name = "defguard-vpc"

  # The CIDR block for the VPC. This defines the IP address range for the VPC and its subnets.
  vpc_cidr = "10.0.0.0/16"

  # The tags to be applied to the Defguard VPC.
  vpc_tags = {
    Name = local.vpc_name
  }

  # The private subnets for the VPC. These subnets are used for the database instance.
  # Note: 2 subnets are required for high availability of the database instance.
  vpc_private_subnets = ["10.0.2.0/24", "10.0.3.0/24"]

  # The subnets for the VPC that will be used for the Defguard Core, proxy, and gateways.
  vpc_public_subnets = ["10.0.1.0/24"]

  # The availability zones for the VPC. This is used mainly for the database instance to ensure high availability.
  azs = ["eu-north-1a", "eu-north-1b"]
}

variable "aws_access_key" {
  description = "AWS access key"
  type        = string
}

variable "aws_secret_key" {
  description = "AWS secret key"
  type        = string
}

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 6.0"
    }
  }
}

data "aws_ami" "ubuntu" {
  most_recent = true
  owners      = ["099720109477"]

  filter {
    name   = "name"
    values = ["ubuntu/images/hvm-ssd-gp3/ubuntu-noble-24.04-amd64-server-*"]
  }
}

provider "aws" {
  region     = local.region
  access_key = var.aws_access_key
  secret_key = var.aws_secret_key
}

resource "random_password" "gateway_secret" {
  length  = 64
  special = false
}

module "defguard_core" {
  # source = "../../modules/core"
  source          = "github.com/DefGuard/deployment//terraform/modules/core?ref=main"
  instance_type   = local.core_instance_type
  package_version = local.core_package_version
  arch            = local.core_arch
  ami             = data.aws_ami.ubuntu.id

  core_url        = local.core_url
  proxy_grpc_port = local.proxy_grpc_port
  proxy_url       = local.proxy_url
  grpc_port       = local.core_grpc_port
  http_port       = local.core_http_port
  cookie_insecure = local.core_cookie_insecure
  vpn_networks = [for network in local.vpn_networks : {
    id       = network.id
    name     = network.name
    address  = network.address
    port     = network.port
    endpoint = aws_eip.defguard_gateway_endpoint[network.id - 1].public_ip
  }]
  db_details = {
    name     = local.db_name
    username = local.db_username
    password = local.db_password
    port     = local.db_port
    address  = aws_db_instance.defguard_core_db.address
  }
  proxy_address        = module.defguard_proxy.proxy_private_address
  gateway_secret       = random_password.gateway_secret.result
  network_interface_id = aws_network_interface.defguard_core_network_interface.id
  # log_level            = "info"
}

module "defguard_proxy" {
  # source = "../../modules/proxy"
  source = "github.com/DefGuard/deployment//terraform/modules/proxy?ref=main"

  instance_type   = local.proxy_instance_type
  package_version = local.proxy_package_version
  arch            = local.proxy_arch
  grpc_port       = local.proxy_grpc_port
  http_port       = local.proxy_http_port
  proxy_url       = local.proxy_url
  # log_level       = "info"

  ami                  = data.aws_ami.ubuntu.id
  network_interface_id = aws_network_interface.defguard_proxy_network_interface.id
}

module "defguard_gateway" {
  count = length(local.vpn_networks)
  # source = "../../modules/gateway"
  source = "github.com/DefGuard/deployment//terraform/modules/gateway?ref=main"

  ami             = data.aws_ami.ubuntu.id
  instance_type   = local.gateway_instance_type
  package_version = local.gateway_package_version
  arch            = local.gateway_arch

  core_grpc_port       = local.core_grpc_port
  nat                  = local.vpn_networks[count.index].nat
  network_id           = local.vpn_networks[count.index].id
  gateway_secret       = random_password.gateway_secret.result
  network_interface_id = aws_network_interface.defguard_gateway_network_interface[count.index].id
  core_address         = aws_network_interface.defguard_core_network_interface.private_ip
  # log_level            = "info"

  depends_on = [module.defguard_core]
}

module "vpc" {
  source = "terraform-aws-modules/vpc/aws"

  name            = local.vpc_name
  cidr            = local.vpc_cidr
  azs             = local.azs
  private_subnets = local.vpc_private_subnets
  public_subnets  = local.vpc_public_subnets

  enable_dns_hostnames = true
  tags                 = local.vpc_tags
}

###########################################################################
####################### Core database configuration #######################
###########################################################################

resource "aws_db_instance" "defguard_core_db" {
  engine                 = "postgres"
  instance_class         = local.db_instance_class
  username               = local.db_username
  password               = local.db_password
  db_name                = local.db_name
  port                   = local.db_port
  skip_final_snapshot    = true
  allocated_storage      = local.db_storage
  db_subnet_group_name   = aws_db_subnet_group.defguard.name
  vpc_security_group_ids = [aws_security_group.defguard_db_sg.id]
  parameter_group_name   = aws_db_parameter_group.defguard_db_parameter_group.name
}

resource "aws_db_parameter_group" "defguard_db_parameter_group" {
  name   = "defguard-db-parameter-group"
  family = "postgres17"

  parameter {
    name  = "rds.force_ssl"
    value = "0"
  }
}

resource "aws_db_subnet_group" "defguard" {
  name       = "defguard-db-subnet-group"
  subnet_ids = module.vpc.private_subnets
}

###########################################################################
######################## Core network configuration #######################
###########################################################################

# Public IP address for the Defguard Core instance
# Remove this if you want to use a private IP only
# or you are running Defguard behind a reverse proxy.
resource "aws_eip" "defguard_core_endpoint" {
  domain = "vpc"
}

resource "aws_eip_association" "defguard_core_endpoint_association" {
  network_interface_id = aws_network_interface.defguard_core_network_interface.id
  allocation_id        = aws_eip.defguard_core_endpoint.id
}

resource "aws_security_group" "defguard_core_sg" {
  name        = "defguard-core-sg"
  description = "Core access"
  vpc_id      = module.vpc.vpc_id

  ########################### General access rules ##########################

  # (optional) SSH access to the Defguard Core server instance
  # ingress {
  #   from_port   = 22
  #   to_port     = 22
  #   protocol    = "tcp"
  #   cidr_blocks = ["0.0.0.0/0"]
  # }

  # HTTP access to the Defguard Core web UI from connected VPN clients
  # Remove this rule if you want to run core only behind a reverse proxy
  # Note that the core access should be limited to the VPN clients and internal networks only.
  ingress {
    from_port = local.core_http_port
    to_port   = local.core_http_port
    protocol  = "tcp"
    cidr_blocks = [
      for eip in aws_eip.defguard_gateway_endpoint : "${eip.public_ip}/32"
    ]
  }

  # Example access from a reverse proxy
  # ingress {
  #   from_port = local.core_http_port
  #   to_port   = local.core_http_port
  #   protocol  = "tcp"
  #   security_groups = [ <your reverse proxy security group ID> ]
  # }

  ########## Security group rules essential for Defguard operation ##########

  # gRPC communication with Defguard Gateways
  ingress {
    from_port = local.core_grpc_port
    to_port   = local.core_grpc_port
    protocol  = "tcp"
    security_groups = [
      for sg in aws_security_group.defguard_gateway_sg : sg.id
    ]
  }

  # General egress
  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

resource "aws_network_interface" "defguard_core_network_interface" {
  subnet_id       = module.vpc.public_subnets[0]
  security_groups = [aws_security_group.defguard_core_sg.id]

  tags = {
    Name = "defguard-core-network-interface"
  }
}

###########################################################################
###################### Gateway network configuration ######################
###########################################################################

# Public IP addresses for the Defguard Gateway instances
# Gateways must be accessible externally to allow VPN clients to connect.

resource "aws_eip" "defguard_gateway_endpoint" {
  count  = length(local.vpn_networks)
  domain = "vpc"
}

resource "aws_eip_association" "defguard_gateway_endpoint_association" {
  count                = length(local.vpn_networks)
  network_interface_id = aws_network_interface.defguard_gateway_network_interface[count.index].id
  allocation_id        = aws_eip.defguard_gateway_endpoint[count.index].id
}

resource "aws_security_group" "defguard_gateway_sg" {
  count       = length(local.vpn_networks)
  name        = "defguard-gateway-sg-${count.index}"
  description = "Gateway access"
  vpc_id      = module.vpc.vpc_id

  ########################### General access rules ##########################

  # (optional) SSH access to the Defguard Gateway server instance
  # ingress {
  #   from_port   = 22
  #   to_port     = 22
  #   protocol    = "tcp"
  #   cidr_blocks = ["0.0.0.0/0"]
  # }

  ########## Security group rules essential for Defguard operation ##########

  # VPN traffic coming from connected clients
  ingress {
    from_port   = local.vpn_networks[count.index].port
    to_port     = local.vpn_networks[count.index].port
    protocol    = "udp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  # General egress
  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

resource "aws_network_interface" "defguard_gateway_network_interface" {
  count           = length(local.vpn_networks)
  subnet_id       = module.vpc.public_subnets[0]
  security_groups = [aws_security_group.defguard_gateway_sg[count.index].id]

  tags = {
    Name = "defguard-gateway-network-interface-${count.index}"
  }
}

###########################################################################
####################### Proxy network configuration #######################
###########################################################################

# Public IP address for the Defguard Proxy instance
# Remove this if you want to run proxy behind a reverse proxy
resource "aws_eip" "defguard_proxy_endpoint" {
  domain = "vpc"
}

resource "aws_eip_association" "defguard_proxy_endpoint_association" {
  network_interface_id = aws_network_interface.defguard_proxy_network_interface.id
  allocation_id        = aws_eip.defguard_proxy_endpoint.id
}

resource "aws_security_group" "defguard_proxy_sg" {
  name        = "defguard-proxy-sg"
  description = "Proxy access"
  vpc_id      = module.vpc.vpc_id

  ########################### General access rules ##########################

  # (optional) SSH access to the Defguard Proxy server instance
  # ingress {
  #   from_port   = 22
  #   to_port     = 22
  #   protocol    = "tcp"
  #   cidr_blocks = ["0.0.0.0/0"]
  # }

  # HTTP access to the Defguard Proxy web UI from anywhere
  # Remove this rule if you want to run proxy behind a reverse proxy
  # Note that the proxy should be accessible externally to allow Defguard clients
  # to communicate through it and to allow the enrollment of new users.
  ingress {
    from_port   = local.proxy_http_port
    to_port     = local.proxy_http_port
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  # Example access from a reverse proxy
  # ingress {
  #   from_port = local.proxy_http_port
  #   to_port   = local.proxy_http_port
  #   protocol  = "tcp"
  #   security_groups = [ <your reverse proxy security group ID> ]
  # }

  ########## Security group rules essential for Defguard operation ##########

  # Internal communication with Defguard Core
  ingress {
    from_port       = local.proxy_grpc_port
    to_port         = local.proxy_grpc_port
    protocol        = "tcp"
    security_groups = [aws_security_group.defguard_core_sg.id]
  }

  # General egress
  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

resource "aws_network_interface" "defguard_proxy_network_interface" {
  subnet_id       = module.vpc.public_subnets[0]
  security_groups = [aws_security_group.defguard_proxy_sg.id]

  tags = {
    Name = "defguard-proxy-network-interface"
  }
}


###########################################################################
###################### Database network configuration #####################
###########################################################################

resource "aws_security_group" "defguard_db_sg" {
  name        = "defguard-db-sg"
  description = "Access to the database"
  vpc_id      = module.vpc.vpc_id

  # Allows access to the database from the Defguard Core instance
  ingress {
    from_port       = local.db_port
    to_port         = local.db_port
    protocol        = "tcp"
    security_groups = [aws_security_group.defguard_core_sg.id]
  }

  tags = {
    Name = "defguard-db-sg"
  }
}

###########################################################################
################################# Outputs #################################
###########################################################################

output "defguard_core_private_address" {
  description = "IP address of Defguard Core instance in the internal network"
  value       = aws_network_interface.defguard_core_network_interface.private_ip
}

output "defguard_core_public_address" {
  description = "Public IP address of Defguard Core instance"
  value       = aws_eip.defguard_core_endpoint.public_ip
}

output "defguard_proxy_public_address" {
  description = "Public IP address of Defguard Proxy instance"
  value       = aws_eip.defguard_proxy_endpoint.public_ip
}

output "defguard_proxy_private_address" {
  description = "Private IP address of Defguard Proxy instance"
  value       = aws_network_interface.defguard_proxy_network_interface.private_ip
}

output "defguard_gateway_public_addresses" {
  description = "Public IP addresses of Defguard Gateway instances"
  value       = [for gw in aws_eip.defguard_gateway_endpoint : gw.public_ip]
}

output "defguard_gateway_private_addresses" {
  description = "Private IP addresses of Defguard Gateway instances"
  value       = [for gw in aws_network_interface.defguard_gateway_network_interface : gw.private_ip]
}