docuconf for Ruby

bundle install

# Until the first release, from the main branch:
gem "docuconf-anyway", git: "https://github.com/Docuconf/docuconf-ruby", branch: "main"

# frozen_string_literal: true

require "docuconf/anyway"

class OrdersConfig < Anyway::Config
  include Docuconf::Anyway

  # Read PORT, DATABASE_URL, ... with no ORDERS_ prefix.
  env_prefix ""

  attr_config :database_url,
    port: 8080, log_level: "info", allowed_origins: ["http://localhost:3000"],
    request_timeout: "30s", worker_count: 4
  required :database_url

  describe :port, "HTTP listen port", min: 1, max: 65_535
  describe :log_level, "Minimum log level", values: %w[debug info warn error]
  describe :database_url, "Postgres connection string for orders", type: :url, schemes: %w[postgres],
    max_length: 2048, secret: true # never printed, and the contract marks it secret
  describe :allowed_origins, "CORS origins allowed to call the API", min_items: 1

  # How long the server works on one request before it gives up.
  #
  # Raise it when clients upload large order batches. Keep it below the load
  # balancer's idle timeout, or the client sees a reset rather than a +504+.
  describe :request_timeout, "Time allowed to handle one request", min: "1s", max: "5m"
  describe :worker_count, "Background workers processing orders", min: 1, max: 64
end

# Loading the config validates it: every problem is reported at once, each
# with a stable code, and the secret's value is never printed. On failure
# load! prints the problems and exits 1.
CONFIG = OrdersConfig.load!

DATABASE_URL=postgres://orders:pw@localhost:5432/orders bundle exec ruby server.rb

$ PORT=0 bundle exec ruby server.rb
docuconf: 2 configuration problems:
  - DATABASE_URL [missing_required]: required, and not set: set DATABASE_URL in the environment (a secret cannot come from a file)
  - PORT [out_of_range]: 0 is below min 1

# frozen_string_literal: true

require "minitest/autorun"
require "anyway/testing"
require_relative "../../orders/config/orders_config"

class OrdersConfigTest < Minitest::Test
  # with_env sets these variables for the block and restores ENV afterwards.
  include Anyway::Testing::Helpers

  def test_defaults
    with_env("DATABASE_URL" => "postgres://orders@db/orders") do
      config = OrdersConfig.new
      assert_equal 8080, config.port
      assert_equal 4, config.worker_count
    end
  end

  def test_rejects_bad_values
    with_env("PORT" => "70000", "DATABASE_URL" => nil) do
      error = assert_raises(Docuconf::Anyway::ValidationError) { OrdersConfig.new }
      assert_includes error.message, "PORT [out_of_range]"
      assert_includes error.message, "DATABASE_URL [missing_required]"
    end
  end
end

bundle exec ruby test/orders_config_test.rb

bundle exec docuconf export --name orders-api --package orders --out contract.cue config/orders_config.rb

// Code generated by docuconf. DO NOT EDIT.
package orders

import "docuconf.dev/contract"

contract.#Contract & {
	apiVersion: "docuconf.dev/v1alpha1"
	kind:       "ConfigContract"
	metadata: {
		name: "orders-api"
		generator: {
			language: "ruby"
			sdk:      "docuconf-anyway"
			version:  "0.1.0"
		}
	}
	vars: {
		ALLOWED_ORIGINS: {
			type:        "list"
			description: "CORS origins allowed to call the API"
			configKey:   "orders.allowed_origins"
			items:       "string"
			encoding:    "csv"
			separator:   ","
			minItems:    1
			default: ["http://localhost:3000"]
		}
		DATABASE_URL: {
			type:        "url"
			description: "Postgres connection string for orders"
			required:    true
			secret:      true
			configKey:   "orders.database_url"
			schemes: ["postgres"]
			maxLength: 2048
		}
		LOG_LEVEL: {
			type:        "enum"
			description: "Minimum log level"
			configKey:   "orders.log_level"
			values: ["debug", "info", "warn", "error"]
			default: "info"
		}
		PORT: {
			type:        "int"
			description: "HTTP listen port"
			configKey:   "orders.port"
			min:         1
			max:         65535
			default:     8080
		}
		REQUEST_TIMEOUT: {
			type:        "duration"
			description: "Time allowed to handle one request"
			details:     "How long the server works on one request before it gives up.\n\nRaise it when clients upload large order batches. Keep it below the load\nbalancer's idle timeout, or the client sees a reset rather than a `504`."
			configKey:   "orders.request_timeout"
			encoding:    "iso8601"
			min:         "1s"
			max:         "5m"
			default:     "30s"
		}
		WORKER_COUNT: {
			type:        "int"
			description: "Background workers processing orders"
			configKey:   "orders.worker_count"
			min:         1
			max:         64
			default:     4
		}
	}
}