Rework application configuration

Use a preinitializer to load the settings from application.yml so
that they are available as early as possible. All settings can also
be overridden using environment variables.

The ad-hoc settins in environment.rb are then moved to this new
system so we have one consistent location for settings.

config/application.yml

@@ -1,4 +1,21 @@
 standard_settings: &standard_settings
+  # The server URL
+  server_url: "www.openstreetmap.org"
+  # The generator
+  generator: "OpenStreetMap server"
+  # Sender addresses for emails
+  email_from: "OpenStreetMap <webmaster@openstreetmap.org>"
+  email_return_path: "bounces@openstreetmap.org"
+  # API version
+  api_version: "0.6"
+  # Application status - posstible values are:
+  #   :online - online and operating normally
+  #   :api_readonly - site online but API in read-only mode
+  #   :api_offline - site online but API offline
+  #   :database_readonly - database and site in read-only mode
+  #   :database_offline - database offline with site in emergency mode
+  #   :gpx_offline - gpx storage offline
+  status: :online
   # The maximum area you're allowed to request, in square degrees
   max_request_area: 0.25
   # Number of GPS trace/trackpoints returned per-page

config/environment.rb

@@ -1,36 +1,8 @@
 # Be sure to restart your server when you modify this file
 
-# Uncomment below to force Rails into production mode when
-# you don't control web/app server and can't set it the proper way
-ENV['RAILS_ENV'] ||= 'production'
-
 # Specifies gem version of Rails to use when vendor/rails is not present
 RAILS_GEM_VERSION = '2.3.8' unless defined? RAILS_GEM_VERSION
 
-# Set the server URL
-SERVER_URL = ENV['OSM_SERVER_URL'] || 'www.openstreetmap.org'
-
-# Set the generator
-GENERATOR = ENV['OSM_SERVER_GENERATOR'] || 'OpenStreetMap server'
-
-# Settings for generated emails (e.g. signup confirmation
-EMAIL_FROM = ENV['OSM_EMAIL_FROM'] || 'OpenStreetMap <webmaster@openstreetmap.org>'
-EMAIL_RETURN_PATH = ENV['OSM_EMAIL_RETURN_PATH'] || 'bounces@openstreetmap.org'
-
-# Application constants needed for routes.rb - must go before Initializer call
-API_VERSION = ENV['OSM_API_VERSION'] || '0.6'
-
-# Set application status - possible settings are:
-#
-#   :online - online and operating normally
-#   :api_readonly - site online but API in read-only mode
-#   :api_offline - site online but API offline
-#   :database_readonly - database and site in read-only mode
-#   :database_offline - database offline with site in emergency mode
-#   :gpx_offline - gpx storage offline
-#
-OSM_STATUS = :online
-
 # Bootstrap the Rails environment, frameworks, and default configuration
 require File.join(File.dirname(__FILE__), 'boot')
 
@@ -43,7 +15,7 @@ Rails::Initializer.run do |config|
   # config.load_paths += %W( #{RAILS_ROOT}/extras )
 
   # Specify gems that this application depends on and have them installed with rake gems:install
-  unless  OSM_STATUS == :database_offline
+  unless  STATUS == :database_offline
     config.gem 'composite_primary_keys', :version => '2.2.2'
   end
   config.gem 'libxml-ruby', :version => '>= 1.1.1', :lib => 'libxml'
@@ -59,7 +31,7 @@ Rails::Initializer.run do |config|
  
   # Skip frameworks you're not going to use. To use Rails without a database,
   # you must remove the Active Record framework.
-  if OSM_STATUS == :database_offline
+  if STATUS == :database_offline
     config.frameworks -= [ :active_record ]
     config.eager_load_paths = []
   end

config/initializers/load_configs.rb

@@ -1,4 +0,0 @@
-# This file loads various yml configuration files
-
-# Load application config
-APP_CONFIG = YAML.load(File.read(RAILS_ROOT + "/config/application.yml"))[RAILS_ENV]

config/initializers/memory_limits.rb

@@ -1,11 +1,11 @@
 # Setup any specified hard limit on the virtual size of the process
-if APP_CONFIG.include?('hard_memory_limit') and Process.const_defined?(:RLIMIT_AS)
-  Process.setrlimit Process::RLIMIT_AS, APP_CONFIG['hard_memory_limit']*1024*1024, Process::RLIM_INFINITY
+if defined?(HARD_MEMORY_LIMIT) and Process.const_defined?(:RLIMIT_AS)
+  Process.setrlimit Process::RLIMIT_AS, HARD_MEMORY_LIMIT*1024*1024, Process::RLIM_INFINITY
 end
 
 # If we're running under passenger and a soft memory limit is
 # configured then setup some rack middleware to police the limit
-if APP_CONFIG.include?('soft_memory_limit') and defined?(PhusionPassenger)
+if defined?(SOFT_MEMORY_LIMIT) and defined?(PhusionPassenger)
   # Define some rack middleware to police the soft memory limit
   class MemoryLimit
     def initialize(app)
@@ -17,7 +17,7 @@ if APP_CONFIG.include?('soft_memory_limit') and defined?(PhusionPassenger)
       status, headers, body = @app.call(env)
       
       # Restart if we've hit our memory limit
-      if resident_size > APP_CONFIG['soft_memory_limit']
+      if resident_size > SOFT_MEMORY_LIMIT
         Process.kill("USR1", 0)
       end
       

config/initializers/session_store.rb

@@ -12,6 +12,6 @@ ActionController::Base.session = {
 # Use the database for sessions instead of the cookie-based default,
 # which shouldn't be used to store highly confidential information
 # (create the session table with "rake db:sessions:create")
-unless OSM_STATUS == :database_offline or OSM_STATUS == :database_readonly
+unless STATUS == :database_offline or STATUS == :database_readonly
   ActionController::Base.session_store = :sql_session_store
 end

config/initializers/sql_session_store.rb

@@ -4,6 +4,6 @@ adapter = Rails.configuration.database_configuration[environment]["adapter"]
 session_class = adapter + "_session"
 
 # Configure SqlSessionStore
-unless  OSM_STATUS == :database_offline
+unless  STATUS == :database_offline
   SqlSessionStore.session_class = session_class.camelize.constantize
 end

config/preinitializer.rb

@@ -0,0 +1,16 @@
+require 'yaml'
+
+config = YAML.load_file("#{RAILS_ROOT}/config/application.yml")
+env = ENV['RAILS_ENV'] || 'development'
+
+ENV.each do |key,value|
+  if key.match(/^OSM_(.*)$/)
+    Object.const_set(Regexp.last_match(1).upcase, value)
+  end
+end
+
+config[env].each do |key,value|
+  unless Object.const_defined?(key.upcase)
+    Object.const_set(key.upcase, value)
+  end
+end