Feature/tagged logging (#1) (#2)

* Add tagged logging support

Implement tagged logging similar to ActiveSupport::TaggedLogging.

* Use log_tags attribute on logger

Don't use the default_options to pass the tags into the logger.  This
causes the tags field to be sent over to graylog as an array.  Instead
pass the tag names into an attribute called log_tags that matches with
the Rails standard of config.log_tags.

* Replace Thread#[] with Thread#thread_variable_get/set

* Skip log tags tests for Ruby 1.9

* Fix CI for JRuby

Co-authored-by: Mark Glenn <[email protected]>
Co-authored-by: Marcus Ilgner <[email protected]>
Co-authored-by: Vladimir Kitaev <[email protected]>

Co-authored-by: Mark Glenn <[email protected]>
Co-authored-by: Marcus Ilgner <[email protected]>
Co-authored-by: Vladimir Kitaev <[email protected]>

Gemfile.lock

@@ -69,6 +69,3 @@ DEPENDENCIES
   rack (< 2.0)
   shoulda (~> 2.11.3)
   test-unit (~> 3.2.0)
-
-BUNDLED WITH
-   1.14.6

lib/gelf/logger.rb

@@ -2,7 +2,7 @@ module GELF
   # Methods for compatibility with Ruby Logger.
   module LoggerCompatibility
 
-    attr_accessor :formatter
+    attr_accessor :formatter, :log_tags
 
     # Use it like Logger#add... or better not to use at all.
     def add(level, message = nil, progname = nil, &block)
@@ -28,9 +28,14 @@ def add(level, message = nil, progname = nil, &block)
         message_hash.merge!(self.class.extract_hash_from_exception(message))
       end
 
-      if message_hash.key?('short_message') && !message_hash['short_message'].empty?
-        notify_with_level(level, message_hash)
+      return if !message_hash.key?('short_message') || message_hash['short_message'].empty?
+
+      # Include tags in message hash
+      Array(log_tags).each_with_index do |tag_name, index|
+        message_hash.merge!("_#{tag_name}" => current_tags[index]) if current_tags[index]
       end
+
+      notify_with_level(level, message_hash)
     end
 
     # Redefines methods in +Notifier+.
@@ -51,12 +56,37 @@ def add(level, message = nil, progname = nil, &block)
     def <<(message)
       notify_with_level(GELF::UNKNOWN, 'short_message' => message)
     end
+
+    def tagged(*tags)
+      new_tags = push_tags(*tags)
+      yield self
+    ensure
+      current_tags.pop(new_tags.size)
+    end
+
+    def push_tags(*tags)
+      tags.flatten.reject{ |t| t.respond_to?(:empty?) ? !!t.empty? : !t }.tap do |new_tags|
+        current_tags.concat new_tags
+      end
+    end
+
+    def current_tags
+      val = Thread.current.thread_variable_get(:gelf_tagged_logging_tags)
+      return val unless val.nil?
+      Thread.current.thread_variable_set(:gelf_tagged_logging_tags, [])
+    end
   end
 
   # Graylog2 notifier, compatible with Ruby Logger.
   # You can use it with Rails like this:
   #     config.logger = GELF::Logger.new("localhost", 12201, "WAN", { :facility => "appname" })
   #     config.colorize_logging = false
+  #
+  # Tagged logging (with tags from rack middleware) (order of tags is important)
+  # Adds custom gelf messages: { '_uuid_name' => <uuid>, '_remote_ip_name' => <remote_ip> }
+  #     config.logger = GELF::Logger.new("localhost", 12201, "LAN", { :facility => "appname" })
+  #     config.log_tags = [:uuid, :remote_ip]
+  #     config.logger.log_tags = [:uuid_name, :remote_ip_name] # Same order as config.log_tags
   class Logger < Notifier
     include LoggerCompatibility
   end

test/test_logger.rb

@@ -237,6 +237,42 @@ class TestLogger < Test::Unit::TestCase
       @logger.formatter
     end
 
+    # Supports only Ruby 2.0 or higher
+    if RUBY_VERSION[0, 1].to_i >= 2
+      context "#tagged" do
+        # logger.tagged("TAG") { logger.info "Message" }
+        should "support tagged method" do
+          @logger.expects(:notify_with_level!).with do |level, hash|
+            level == GELF::INFO &&
+              hash['short_message'] == 'Message' &&
+              hash['facility'] == 'gelf-rb'
+          end
+
+          str = "TAG"
+          str.stubs(:blank?).returns(true)
+
+          @logger.tagged(str) { @logger.info "Message" }
+        end
+
+        should "set custom gelf message with tag name and tag content" do
+          # I want the first tag with name 'test_tag'
+          @logger.log_tags = [:test_tag]
+
+          @logger.expects(:notify_with_level!).with do |level, hash|
+            level == GELF::INFO &&
+              hash['short_message'] == 'Message' &&
+              hash['facility'] == 'gelf-rb' &&
+              hash['_test_tag'] == 'TAG' # TAG should be in the hash
+          end
+
+          str = "TAG"
+          str.stubs(:blank?).returns(false)
+
+          @logger.tagged(str) { @logger.info "Message" }
+        end
+      end
+    end
+
     context "close" do
       should "close socket" do
         @sender.expects(:close).once