Support named_tags in Rails Rack logger.

Author: reidmorrison

lib/rails_semantic_logger/engine.rb

@@ -56,6 +56,20 @@ class Engine < ::Rails::Engine
     # Silence asset logging
     config.rails_semantic_logger.quiet_assets      = false
 
+    # Hash of named tags.
+    # Use in a similar fashion to the Rails config.log_tags, except that it is now a hash.
+    #
+    # Example:
+    #   config.rails_semantic_logger.named_tags = {
+    #     request_id: :request_id,
+    #     ip:         :remote_ip,
+    #     user:       -> request { request.cookie_jar['login'] }
+    #   }
+    #
+    # Notes:
+    # - Nil Values are ignored and will be left out of the named tags.
+    config.rails_semantic_logger.named_tags        = nil
+
     # Initialize SemanticLogger. In a Rails environment it will automatically
     # insert itself above the configured rails logger to add support for its
     # additional features
@@ -194,6 +208,10 @@ class Engine < ::Rails::Engine
       if config.rails_semantic_logger.processing
         require('rails_semantic_logger/extensions/action_controller/log_subscriber_processing') if defined?(ActionView::LogSubscriber)
       end
+
+      if config.rails_semantic_logger.named_tags && defined?(Rails::Rack::Logger)
+        Rails::Rack::Logger.named_tags = config.rails_semantic_logger.named_tags
+      end
     end
 
     # Before any initializers run, but after the gems have been loaded

lib/rails_semantic_logger/extensions/rails/rack/logger.rb

@@ -4,10 +4,20 @@
 module Rails
   module Rack
     class Logger
-      @@logger = SemanticLogger['Rack']
+      mattr_accessor :named_tags
+
+      @logger = SemanticLogger['Rack']
 
       def self.logger
-        @@logger
+        @logger
+      end
+
+      def call(env)
+        request = ActionDispatch::Request.new(env)
+
+        proc = -> { call_app(request, env) }
+        proc = -> { logger.tagged(compute_tags(request), &proc) } if @taggers && !@taggers.empty?
+        named_tags ? SemanticLogger.named_tagged(compute_named_tags(request), &proc) : proc.call
       end
 
       def started_request_message(request)
@@ -27,6 +37,23 @@ def logger
         self.class.logger
       end
 
+      def compute_named_tags(request) # :doc:
+        tagged = {}
+        named_tags.each_pair do |tag, value|
+          resolved =
+            case value
+            when Proc
+              value.call(request)
+            when Symbol
+              request.send(value)
+            else
+              value
+            end
+          tagged[tag] = resolved unless resolved.nil?
+        end
+        tagged
+      end
+
     end
   end
 end

lib/rails_semantic_logger/extensions/rails/rack/logger_info_as_debug.rb

@@ -5,7 +5,7 @@ module Rails
   module Rack
     class Logger
       def self.logger
-        @@logger
+        @logger
       end
 
       private
@@ -23,8 +23,8 @@ def logger
         self.class.logger
       end
 
-      @@logger = SemanticLogger['Rack']
-      @@logger.extend(LogInfoAsDebug)
+      @logger = SemanticLogger['Rack']
+      @logger.extend(LogInfoAsDebug)
     end
   end
 end

lib/rails_semantic_logger/version.rb

@@ -1,3 +1,3 @@
 module RailsSemanticLogger #:nodoc
-  VERSION = '4.0.1'
+  VERSION = '4.1.0'
 end

rails_semantic_logger.gemspec

@@ -18,5 +18,5 @@ Gem::Specification.new do |spec|
   spec.has_rdoc              = true
   spec.required_ruby_version = '>= 2.1'
   spec.add_dependency 'rails', '>= 4.0'
-  spec.add_dependency 'semantic_logger', '~> 4.0'
+  spec.add_dependency 'semantic_logger', '~> 4.1'
 end