1711-Games / LGN-Config

Simple config engine for server-side Swift applications

LGNConfig

This package contains a simple config engine.

LGNConfig usage

In order to use this class you have to define an enum with all config keys. Example:

public enum ConfigKey: String, AnyConfigKey {
    case KEY
    case SALT
    case LOG_LEVEL
    case HTTP_PORT
    case PRIVATE_IP
    case REGISTER_TO_CONSUL
}

Then you try to init the config. main.swift is not the worst place for it, as it doesn't require try calls to be wrapped with do catch:

let config = try Config<ConfigKey>(
    // this is optional, you may provide any `[AnyHashable: String]` input here
    rawConfig: ProcessInfo.processInfo.environment,
    // optional, default value is `false`
    isLocal: true,
    // optional, see below
    localConfig: [
        .KEY: "sdfdfg",
        .SALT: "mysecretsalt",
        .LOG_LEVEL: "trace",
        .HTTP_PORT: "8081",
        .PRIVATE_IP: "127.0.0.1",
        .REGISTER_TO_CONSUL: "false",
    ]
)

localConfig argument contains default config entries for local app environment which are used only when isLocal is set to true, otherwise it exits the application with respective message if one or more config entries are missing from config. Then you use config like this:

let cryptor = try LGNP.Cryptor(salt: config[.SALT], key: config[.KEY])

Please notice that subscript with enum keys returns non-optional string value. It's because all keys are expected to be present in initialized config, and if not, there is something very wrong with LGNConfig, and should be reported.

Additionally you can try to get a config value by string key name:

let HTTPPort: String? = config["HTTP_PORT"]

This call returns optional string because of obvious reasons.

Vapor compatibility

If you'd like to use it in a Vapor 4 project, you may create this handy layer of compatibility. In my projects it's called Vapor+LGNConfig.swift. The initializer now accepts Vapor's Environment struct instead of isLocal, and so local config would be used only in .development environment. Additionally, you will be able to use config from Application, that is, as app.config at bootstrap stage or as request.application.config in routes. You just need to init the config in configure.swift and assign it to app.config.

import LGNConfig
import Vapor

public extension Config {
    init(env: Environment, localConfig: [Key: String] = [:]) throws {
        try self.init(isLocal: env == Environment.development, localConfig: localConfig)
    }
}

public extension Application {
    fileprivate struct StorageConfigKey: StorageKey {
        typealias Value = Config<ConfigKey>
    }

    var config: Config<ConfigKey> {
        get {
            guard let config = self.storage[StorageConfigKey.self] else {
                fatalError("LGN Config not initiated")
            }
            return config
        }
        set {
            self.storage[StorageConfigKey.self] = newValue
        }
    }
}