Config: Get environment from RAILS_ENV, too

  - as well as from RACK_ENV
  - this is part of the effort to bring the configuration defaults from
    the puma-heroku plugin to Puma

History.md

@@ -3,6 +3,7 @@
 * Features
   * Strip whitespace at end of HTTP headers (#2010)
   * Optimize HTTP parser for JRuby (#2012)
+  * Configuration: `environment` is read from `RAILS_ENV`, if `RACK_ENV` can't be found (#2022)
 
 * Bugfixes
   * Fix Errno::EINVAL when SSL is enabled and browser rejects cert (#1564)

README.md

@@ -219,7 +219,7 @@ You can also provide a configuration file with the `-C` (or `--config`) flag:
 $ puma -C /path/to/config
 ```
 
-If no configuration file is specified, Puma will look for a configuration file at `config/puma.rb`. If an environment is specified, either via the `-e` and `--environment` flags, or through the `RACK_ENV` environment variable, Puma looks for configuration at `config/puma/<environment_name>.rb`.
+If no configuration file is specified, Puma will look for a configuration file at `config/puma.rb`. If an environment is specified, either via the `-e` and `--environment` flags, or through the `RACK_ENV` or the `RAILS_ENV` environment variables, Puma looks for configuration at `config/puma/<environment_name>.rb`.
 
 If you want to prevent Puma from looking for a configuration file in those locations, provide a dash as the argument to the `-C` (or `--config`) flag:
 

lib/puma/configuration.rb

@@ -182,7 +182,7 @@ def puma_default_options
         :worker_shutdown_timeout => DefaultWorkerShutdownTimeout,
         :remote_address => :socket,
         :tag => method(:infer_tag),
-        :environment => -> { ENV['RACK_ENV'] || "development" },
+        :environment => -> { ENV['RACK_ENV'] || ENV['RAILS_ENV'] || "development" },
         :rackup => DefaultRackup,
         :logger => STDOUT,
         :persistent_timeout => Const::PERSISTENT_TIMEOUT,

lib/puma/control_cli.rb

@@ -22,7 +22,7 @@ def initialize(argv, stdout=STDOUT, stderr=STDERR)
       @control_auth_token = nil
       @config_file = nil
       @command = nil
-      @environment = ENV['RACK_ENV'] || "development"
+      @environment = ENV['RACK_ENV'] || ENV['RAILS_ENV'] || "development"
 
       @argv = argv.dup
       @stdout = stdout

test/test_config.rb

@@ -246,6 +246,15 @@ def test_config_files_with_rack_env
     end
   end
 
+  def test_config_files_with_rails_env
+    with_env('RAILS_ENV' => 'fake-env') do
+      conf = Puma::Configuration.new do
+      end
+
+      assert_equal ['config/puma/fake-env.rb'], conf.config_files
+    end
+  end
+
   def test_config_files_with_specified_environment
     conf = Puma::Configuration.new do
     end