PoC

lib/puma/launcher.rb

@@ -87,6 +87,8 @@ def initialize(conf, launcher_args={})
       Puma.stats_object = @runner
 
       @status = :run
+
+      log_config if ENV['LOG_CONFIG']
     end
 
     attr_reader :binder, :events, :config, :options, :restart_dir
@@ -521,5 +523,21 @@ def with_unbundled_env
         Bundler.with_unbundled_env { yield }
       end
     end
+
+    def log_config
+      log "Configuration:"
+
+      @config.options.default_options
+        .merge(@config.options.file_options)
+        .merge(@config.options.user_options)
+        .each { |config_key, value| log "-#{config_key}: #{value}" }
+
+      if @config.plugins.instances.size > 0
+        log "\nLoaded plugins:"
+        log @config.plugins.instances
+      end
+
+      log "\n"
+    end
   end
 end

lib/puma/plugin.rb

@@ -4,6 +4,8 @@ module Puma
   class UnknownPlugin < RuntimeError; end
 
   class PluginLoader
+    attr_reader :instances
+
     def initialize
       @instances = []
     end