Loading settings from ENV. A task pushing settings to Heroku

Author: Sidelnikov Stanislav

lib/rails_config.rb

@@ -9,8 +9,9 @@ module RailsConfig
   # ensures the setup only gets run once
   @@_ran_once = false
 
-  mattr_accessor :const_name
+  mattr_accessor :const_name, :use_env
   @@const_name = "Settings"
+  @@use_env = false
 
   def self.setup
     yield self if @@_ran_once == false
@@ -28,6 +29,7 @@ def self.load_files(*files)
     end
 
     config.load!
+    config.load_env! if @@use_env
     config
   end
 

lib/rails_config/integration/rails.rb

@@ -3,6 +3,9 @@ module Integration
     module Rails3
       if defined?(Rails::Railtie)
         class Railtie < Rails::Railtie
+          rake_tasks do
+            Dir[File.join(File.dirname(__FILE__),'../tasks/*.rake')].each { |f| load f }
+          end
 
           # manually load the custom initializer before everything else
           initializer :load_custom_rails_config, :before => :load_environment_config, :group => :all do

lib/rails_config/options.rb

@@ -16,6 +16,24 @@ def add_source!(source)
       @config_sources << source
     end
 
+    def reload_env!
+      conf = Hash.new
+      ENV.each do |key, value|
+        next unless key.to_s.index(RailsConfig.const_name) == 0
+        hash = value
+        key.to_s.split('.').reverse.each do |element|
+          hash = {element => hash}
+        end
+        DeepMerge.deep_merge!(hash, conf, :preserve_unmergeables => false)
+      end
+
+      merge!(conf[RailsConfig.const_name] || {})
+
+      return self
+    end
+
+    alias :load_env! :reload_env!
+
     # look through all our sources and rebuild the configuration
     def reload!
       conf = {}
@@ -32,6 +50,8 @@ def reload!
       # swap out the contents of the OStruct with a hash (need to recursively convert)
       marshal_load(__convert(conf).marshal_dump)
 
+      reload_env! if RailsConfig.use_env
+
       return self
     end
 

lib/rails_config/railtie.rb

@@ -0,0 +1,8 @@
+require 'rails'
+module RailsConfig
+  class Railtie < Rails::Railtie
+    rake_tasks do
+      Dir[File.join(File.dirname(__FILE__),'tasks/*.rake')].each { |f| load f }
+    end
+  end
+end

lib/rails_config/tasks/heroku.rake

@@ -0,0 +1,7 @@
+require 'rails_config'
+require 'tasks.rb'
+namespace 'rails_config' do
+  task :heroku => :environment do |_, args|
+    RailsConfig::Tasks::Heroku.new(args[:app]).invoke
+  end
+end

lib/rails_config/tasks/task.rake

@@ -0,0 +1,3 @@
+task :test do
+  puts 'A test task'
+end

lib/tasks.rb

@@ -0,0 +1,60 @@
+require "bundler"
+
+module RailsConfig
+  module Tasks
+    class Heroku < Struct.new(:app)
+      def invoke
+        puts 'Setting vars...'
+        heroku_command = "config:set #{vars}"
+        heroku(heroku_command)
+        puts 'Vars set:'
+        puts heroku_command
+      end
+
+      def vars
+        # Load only local options to Heroku
+        RailsConfig.load_and_set_settings(
+            Rails.root.join("config", "settings.local.yml").to_s,
+            Rails.root.join("config", "settings", "#{environment}.local.yml").to_s,
+            Rails.root.join("config", "environments", "#{environment}.local.yml").to_s
+        )
+
+        out = ''
+        dotted_hash = to_dotted_hash Kernel.const_get(RailsConfig.const_name).to_hash
+        dotted_hash.each {|key, value| out += " #{key}=#{value} "}
+        out
+      end
+
+      def environment
+        heroku("run 'echo $RAILS_ENV'").chomp[/(\w+)\z/]
+      end
+
+      def heroku(command)
+        with_app = app ? " --app #{app}" : ""
+        `heroku #{command}#{with_app}`
+        #puts "heroku #{command}#{with_app}"
+      end
+
+      def `(command)
+        Bundler.with_clean_env { super }
+      end
+
+      def to_dotted_hash(source, target = {}, namespace = nil)
+        prefix = "#{namespace}." if namespace
+        case source
+          when Hash
+            source.each do |key, value|
+              to_dotted_hash(value, target, "#{prefix}#{key}")
+            end
+          when Array
+            source.each_with_index do |value, index|
+              to_dotted_hash(value, target, "#{prefix}#{index}")
+            end
+          else
+            target[namespace] = source
+        end
+        target
+      end
+    end
+  end
+end

spec/fixtures/env/settings.yml

@@ -0,0 +1,4 @@
+Settings.test_var: 123
+Settings.size: 3
+Settings.hash_test.one: 1-1
+Settings.hash_test.two: 1-2

spec/rails_config_spec.rb

@@ -66,6 +66,45 @@
     Settings.size.should eq 2
   end
 
+  context "ENV variables" do
+    let(:config) do
+      RailsConfig.load_files(setting_path("settings.yml"))
+    end
+
+    before :all do
+      load_env(setting_path('env/settings.yml'))
+      RailsConfig.use_env = true
+    end
+    after :all do
+      RailsConfig.use_env = false
+    end
+
+    it "should load basic ENV variables" do
+      config.load_env!
+      config.test_var.should eq "123"
+    end
+
+    it "should load nested sections" do
+      config.load_env!
+      config.hash_test.one.should eq "1-1"
+    end
+
+    it "should override settings from files" do
+      RailsConfig.load_and_set_settings [setting_path("settings.yml")]
+
+      Settings.server.should eq "google.com"
+      Settings.size.should eq "3"
+    end
+
+    it "should reload env" do
+      RailsConfig.load_and_set_settings [setting_path("settings.yml")]
+      RailsConfig.reload!
+
+      Settings.server.should eq "google.com"
+      Settings.size.should eq "3"
+    end
+  end
+
   context "Nested Settings" do
     let(:config) do
       RailsConfig.load_files(setting_path("development.yml"))

spec/spec_helper.rb

@@ -21,5 +21,13 @@ def setting_path(filename)
     @fixture_path.join(filename)
   end
 
+  # loads ENV vars from a file
+  def load_env(filename)
+    if filename and File.exists?(filename.to_s)
+      result = YAML.load(ERB.new(IO.read(filename.to_s)).result)
+    end
+    result.each { |key, value| ENV[key.to_s] = value.to_s } unless result.nil?
+  end
+
 end