ConfigDefault

ConfigDefault is a simple way to separate your test/development config from your staging/production config. Designed to work with Rails. It depends on ActiveSupport.

Installation

Add this line to your application's Gemfile:

gem "config_default"

And then execute:

$ bundle install

Or install it yourself as:

$ gem install config_default

Configuration

You can control your configuration path and postfix which ConfigDefault will use. Please use it in your application.rb file. This example implement default values:

ConfigDefault.configure do |config|
  config.config_path = "./config"
  config.postfix = "default"
end

If you want to implement Rails monkey patches for Rails.application.config_for and ability to separate database.yml file you need to execute #apply_rails_patch! method in your application.rb file before application init.

  ConfigDefault.apply_rails_patch!

Usage

Default behaviour

First you need to separate you configuration to .default and not. Let's check an example for Rails default config file config/database.yml:

# config/database.default.yml
default: &default
  adapter: postgres
  max_connections: 5
  host: postgres
  database: db

development:
  <<: *default
  database: db_development

test:
  <<: *default
  database: db_test

staging: *default

production: *default

public_production: *default

So this config file is enough for development/test environment. But in staging/production you need to add other SECRET variables to this config. Now you can do in your secret repository this:

# config/database.yml
production:
  user: db_superuser
  password: db_password

All you need after creating this file in your secret location is to place this file near with the .default one. ConfigDefault will merge them automatically on startup.

Your application configuration

Also ConfigDefault can help you with your application config and secrets. Just create config/app.default.yml (test/staging) and config/app.yml (staging/production) files. And then in your application load it:

config = ConfigDefault.load(:app)

It will load result hash with merging app.yml and app.default.yml files. By default ConfigDefault load YAML files as is. So it's mean that what key (string or symbol) you will define in the YAML file => it'll be the same on #load result.

You can change this behaviour with #load options:

config = ConfigDefault.load(:app, symbolize_keys: true) # Hash with symbolized first keys
config = ConfigDefault.load(:app, deep_symbolize_keys: true) # Hash with symbolized all keys

By default ConfigDefault using Rails.env to determnine what key you need from you config file. You can pass this key by your own:

config = ConfigDefault.load(:app, key: nil) # Will not use key at all and result by full file
config = ConfigDefault.load(:app, key: "preprod") # Will search preprod key in file

#load_struct method

If you want to use configuration as a struct object you can use #load_struct method. Let's see an example with database.yaml config above:

config = ConfigDefault.load_struct(:database)
config.host
# => "postgres"
config.lolkek
# => StandardError: There is no option :lolkek in configuration.

If your want to not raise an error on wrong key using (sometimes it's helpful) please use allow_nil option:

config = ConfigDefault.load_struct(:database, allow_nil: true)
config.host
# => "postgres"
config.lolkek
# => nil

If your need nested object using use recursive option on configuration load:

# config/app.default.yml
first:
  second:
    third: "option"

config = ConfigDefault.load_struct(:app, key: nil, recursive: true)
config.first.second.third
# => "option"

At any setting you can use #to_hash method to get a Hash for this configuration branch. It will be ActiveSupport::HashWithIndifferentAccess. Example with app.default.yml from above:

config = ConfigDefault.load_struct(:app, key: nil, recursive: true)
config.to_hash
# => { "first" => { "second" => { "third" => "option" } } }
config.first.to_hash
# => { "second" => { "third" => "option" } }
config.first.second.to_hash
# => { "third" => "option" }

Using ConfigDefault::Struct without configuration load

You can use ConfigDefault::Struct to achive ability to create config object from Hash objects. Here an example of creation struct object on the fly:

config_on_the_fly = { first: { second: { third: "option" } } }
config = ConfigDefault::Struct.new(config_on_the_fly, recursive: true)
config.first.to_hash
# => { "second" => { "third" => "option" } }
config.first.second.third
# => "option"
config.first.lolkek
# => StandardError: There is no option :lolkek in configuration.

ConfigDefault::Struct supports recursive and allow_nil options.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/skirushkin/config_default.

License

The gem is available as open source under the terms of the MIT License.