Add option to write logs to a file

lib/sidekiq/cli.rb

@@ -56,15 +56,12 @@ module Sidekiq
 
     def parse(args=ARGV)
       @code = nil
-      Sidekiq.logger
 
       cli = parse_options(args)
       config = parse_config(cli)
       options.merge!(config.merge(cli))
 
-      Sidekiq.logger.level = Logger::DEBUG if options[:verbose]
-      Celluloid.logger = nil unless options[:verbose]
-
+      initialize_logger
       validate!
       write_pid
       boot_system
@@ -200,6 +197,10 @@ module Sidekiq
           opts[:config_file] = arg
         end
 
+        o.on '-L', '--logfile PATH', "path to writable logfile" do |arg|
+          opts[:logfile] = arg
+        end
+
         o.on '-V', '--version', "Print version and exit" do |arg|
           puts "Sidekiq #{Sidekiq::VERSION}"
           die(0)
@@ -215,6 +216,17 @@ module Sidekiq
       opts
     end
 
+    def initialize_logger
+      if options[:logfile]
+        Sidekiq.logger = Sidekiq::Logging.new_file_logger(options[:logfile])
+      else
+        Sidekiq.logger
+      end
+
+      Sidekiq.logger.level = Logger::DEBUG if options[:verbose]
+      Celluloid.logger = nil unless options[:verbose]
+    end
+
     def write_pid
       if path = options[:pidfile]
         File.open(path, 'w') do |f|

lib/sidekiq/logging.rb

@@ -25,13 +25,12 @@ module Sidekiq
       end
     end
 
+    def self.new_file_logger(file_path)
+      initialize_logger(file_path)
+    end
+
     def self.logger
-      @logger ||= begin
-        log = Logger.new(STDOUT)
-        log.level = Logger::INFO
-        log.formatter = Pretty.new
-        log
-      end
+      @logger ||= initialize_logger(STDOUT)
     end
 
     def self.logger=(log)
@@ -42,5 +41,13 @@ module Sidekiq
       Sidekiq::Logging.logger
     end
 
+    private
+
+    def self.initialize_logger(log_target)
+      log = Logger.new(log_target)
+      log.level = Logger::INFO
+      log.formatter = Pretty.new
+      log
+    end
   end
 end

test/config.yml

@@ -3,6 +3,7 @@
 :environment:  xzibit
 :require:      ./test/fake_env.rb
 :pidfile:      /tmp/sidekiq-config-test.pid
+:logfile:      /tmp/sidekiq.log
 :concurrency:  50
 :queues:
   - [<%="very_"%>often, 2]

test/test_cli.rb

@@ -83,6 +83,47 @@ class TestCli < MiniTest::Unit::TestCase
       Sidekiq.logger.level = old
     end
 
+    describe 'with logfile' do
+      before do
+        @old_logger = Sidekiq.logger
+        @tmp_log_path = '/tmp/sidekiq.log'
+      end
+
+      after do
+        Sidekiq.logger = @old_logger
+        Sidekiq.options.delete(:logfile)
+        File.unlink @tmp_log_path if File.exists?(@tmp_log_path)
+      end
+
+      it 'sets the logfile path' do
+        @cli.parse(['sidekiq', '-L', @tmp_log_path, '-r', './test/fake_env.rb'])
+
+        assert_equal @tmp_log_path, Sidekiq.options[:logfile]
+      end
+
+      it 'creates and writes to a logfile' do
+        @cli.parse(['sidekiq', '-L', @tmp_log_path, '-r', './test/fake_env.rb'])
+
+        Sidekiq.logger.info('test message')
+
+        assert_match /test message/, File.read(@tmp_log_path), "didn't include the log message"
+      end
+
+      it 'appends messages to a logfile' do
+        File.open(@tmp_log_path, 'w') do |f|
+          f.puts 'already existant log message'
+        end
+
+        @cli.parse(['sidekiq', '-L', @tmp_log_path, '-r', './test/fake_env.rb'])
+
+        Sidekiq.logger.info('test message')
+
+        log_file_content = File.read(@tmp_log_path)
+        assert_match /already existant/, log_file_content, "didn't include the old message"
+        assert_match /test message/, log_file_content, "didn't include the new message"
+      end
+    end
+
     describe 'with pidfile' do
       before do
         @tmp_file = Tempfile.new('sidekiq-test')
@@ -134,6 +175,10 @@ class TestCli < MiniTest::Unit::TestCase
         assert_equal '/tmp/sidekiq-config-test.pid', Sidekiq.options[:pidfile]
       end
 
+      it 'sets logfile' do
+        assert_equal '/tmp/sidekiq.log', Sidekiq.options[:logfile]
+      end
+
       it 'sets queues' do
         assert_equal 2, Sidekiq.options[:queues].count { |q| q == 'very_often' }
         assert_equal 1, Sidekiq.options[:queues].count { |q| q == 'seldom' }