Model/infrastructure/terraform/lambda/fast-api/main.tf

############################################
# Load Terraform State
############################################
data "terraform_remote_state" "shared" {
  backend = "s3"
  config = {
    bucket = "assessment-model-terraform-state"
    key = "env:/${var.stage}/terraform.tfstate"
    region = "eu-west-2"
  }
}

data "terraform_remote_state" "engine" {
  backend = "s3"
  config = {
    bucket = "ara-engine-terraform-state",
    key = "env:/${var.stage}/terraform.tfstate"
    region = "eu-west-2"
  }
}

data "terraform_remote_state" "categorisation" {
  backend = "s3"
  config = {
    bucket = "categorisation-terraform-state",
    key = "env:/${var.stage}/terraform.tfstate"
    region = "eu-west-2"
  }
}

############################################
# Load Credentials
############################################
data "aws_secretsmanager_secret_version" "db_credentials" {
  secret_id = "${var.stage}/assessment_model/db_credentials"
}

locals {
  db_credentials = jsondecode(data.aws_secretsmanager_secret_version.db_credentials.secret_string)
}

############################################
# FastAPI Lambda + API Gateway
############################################
module "fastapi" {
  source     = "../../modules/lambda_with_api_gateway"

  name        = "fastapi"
  stage       = var.stage
  source_dir  = "${path.root}/../../../../"
  handler     = "backend.app.main.handler"
  runtime     = "python3.11"
  timeout     = 600
  memory_size = 512
  artifact_bucket = data.terraform_remote_state.shared.outputs.ara_fast_api_state_bucket
  requirements_file = "${path.root}/../../../../backend/app/requirements/requirements.txt"

  domain_name = "api.${var.domain_name}"

  environment = {
    ENVIRONMENT    = var.stage
    API_KEY        = var.api_key
    SECRET_KEY     = var.secret_key
    # DOMAIN_NAME    = var.domain_name
    EPC_AUTH_TOKEN = var.epc_auth_token
    GOOGLE_SOLAR_API_KEY = var.google_solar_api_key

    DB_HOST     = var.db_host
    DB_NAME     = var.db_name
    DB_PORT     = var.db_port
    DB_USERNAME = local.db_credentials.db_assessment_model_username
    DB_PASSWORD = local.db_credentials.db_assessment_model_password

    PLAN_TRIGGER_BUCKET             = data.terraform_remote_state.shared.outputs.retrofit_plan_trigger_bucket_name
    DATA_BUCKET                     = data.terraform_remote_state.shared.outputs.retrofit_sap_data_bucket_name
    SAP_PREDICTIONS_BUCKET          = data.terraform_remote_state.shared.outputs.retrofit_sap_predictions_bucket_name
    CARBON_PREDICTIONS_BUCKET       = data.terraform_remote_state.shared.outputs.retrofit_carbon_predictions_bucket_name
    HEAT_PREDICTIONS_BUCKET         = data.terraform_remote_state.shared.outputs.retrofit_heat_predictions_bucket_name
    HEATING_KWH_PREDICTIONS_BUCKET  = data.terraform_remote_state.shared.outputs.retrofit_heating_kwh_predictions_bucket_name
    HOTWATER_KWH_PREDICTIONS_BUCKET = data.terraform_remote_state.shared.outputs.retrofit_hotwater_kwh_predictions_bucket_name
    ENERGY_ASSESSMENTS_BUCKET       = data.terraform_remote_state.shared.outputs.retrofit_energy_assessments_bucket_name

    ENGINE_SQS_URL         = data.terraform_remote_state.engine.outputs.ara_engine_queue_url
    CATEGORISATION_SQS_URL = data.terraform_remote_state.categorisation.outputs.categorisation_queue_url
  }
}

############################################
# IAM policy attachments
############################################
# SQS
module "fastapi_sqs_policy" {
  source = "../../modules/general_iam_policy"

  policy_name        = "fastapi-sqs-send-${var.stage}"
  policy_description = "Allow FastAPI to send messages to engine & categorisation queues"

  actions = [
    "sqs:SendMessage"
  ]

  resources = [
    data.terraform_remote_state.engine.outputs.ara_engine_queue_arn,
    data.terraform_remote_state.categorisation.outputs.categorisation_queue_arn
  ]

  conditions = null

  tags = {
    Service = "fastapi"
    Stage   = var.stage
  }
}

resource "aws_iam_role_policy_attachment" "fastapi_sqs_send" {
  role       = module.fastapi.role_name
  policy_arn = module.fastapi_sqs_policy.policy_arn
}

# S3
resource "aws_iam_role_policy_attachment" "fastapi_s3_read_and_write" {
  role       = module.fastapi.role_name
  policy_arn = data.terraform_remote_state.shared.outputs.fast_api_s3_read_and_write_arn
}