Topic: merge Add a syslog sink and a tiny utility for testing logging…

… to syslog

from the commandline.

Change-Id: I8e0c23b376b8e68fe7d8607f3e88c101da5d37e8

vcap_logging/bin/test_syslog

@@ -0,0 +1,40 @@
+#!/usr/bin/env ruby
+# A very simple test script for logging to syslog
+#
+$LOAD_PATH.unshift(File.expand_path("../../lib", __FILE__))
+
+require 'optparse'
+
+require 'vcap/logging'
+
+opts = {
+  :level => :info,
+  :name  => 'test_syslog',
+}
+parser = OptionParser.new do |op|
+  op.banner = "Usage: test_syslog [opts] <message>"
+
+  op.on('-l [LEVEL]', '--level [LEVEL]', 'Foo') {|level| opts[:level] = level.to_sym }
+  op.on('-n [NAME]', '--name [NAME]', 'Bar') {|name| opts[:name] = name }
+
+end
+parser.parse!
+
+unless ARGV.length > 0
+  puts parser.help
+  exit 1
+end
+
+formatter = VCAP::Logging::Formatter::DelimitedFormatter.new do
+  timestamp
+  log_level
+  fiber_shortid
+  thread_shortid
+  process_id
+  data
+end
+sink = VCAP::Logging::Sink::SyslogSink.new(opts[:name], :formatter => formatter)
+VCAP::Logging.add_sink(nil, nil, sink)
+
+log = VCAP::Logging.logger('test')
+log.send(opts[:level], ARGV.join(' '))

vcap_logging/lib/vcap/logging.rb

@@ -71,6 +71,10 @@ def logger(name)
         @loggers[name]
       end
 
+      def add_sink(*args)
+        @sink_map.add_sink(*args)
+      end
+
       # Sets the log level to _log_level_ for every logger whose name matches _path_regex_
       #
       # @param  path_regex      String  Regular expression to use when matching against the logger name

vcap_logging/lib/vcap/logging/sink.rb

@@ -1,2 +1,3 @@
 require 'vcap/logging/sink/base_sink'
 require 'vcap/logging/sink/file_sink'
+require 'vcap/logging/sink/syslog_sink'

vcap_logging/lib/vcap/logging/sink/base_sink.rb

@@ -2,6 +2,8 @@
 
 require 'vcap/logging/log_record'
 
+require 'thread'
+
 module VCAP
   module Logging
     module Sink

vcap_logging/lib/vcap/logging/sink/syslog_sink.rb

@@ -0,0 +1,68 @@
+require 'syslog'
+
+require 'vcap/logging/sink/base_sink'
+
+module VCAP::Logging::Sink
+
+  # A sink for logging messages to the local syslog server.
+  # NB: The ruby syslog module is a thin wrapper around glibc syslog(). It will first
+  #     attempt to open a unix stream socket to '/dev/log', and upon failure will attempt
+  #     to open a unix datagram socket there. Make sure you configure your syslog server
+  #     to use the appropriate type (probably dgram in our case).
+  #
+  #     Beware that all messages will be silently lost if the syslog server goes away.
+  class SyslogSink < BaseSink
+
+    DEFAULT_LOG_LEVEL_MAP = {
+      :fatal  => Syslog::LOG_CRIT,
+      :error  => Syslog::LOG_ERR,
+      :warn   => Syslog::LOG_WARNING,
+      :info   => Syslog::LOG_INFO,
+      :debug  => Syslog::LOG_DEBUG,
+      :debug1 => Syslog::LOG_DEBUG,
+      :debug2 => Syslog::LOG_DEBUG,
+    }
+
+    # @param  prog_name  String  Program name to identify lines logged to syslog
+    # @param  opts       Hash    :log_level_map  Map of log level => syslog level
+    #                            :formatter      LogFormatter
+    def initialize(prog_name, opts={})
+      super(opts[:formatter])
+
+      @prog_name     = prog_name
+      @log_level_map = opts[:log_level_map] || DEFAULT_LOG_LEVEL_MAP
+      @syslog        = nil
+      open
+    end
+
+    def open
+      @mutex.synchronize do
+        unless @opened
+          @syslog = Syslog.open(@prog_name, Syslog::LOG_CONS | Syslog::LOG_PID, Syslog::LOG_USER)
+          @opened = true
+        end
+      end
+    end
+
+    def close
+      @mutex.synchronize do
+        if @opened
+          @syslog.close
+          @syslog = nil
+          @opened = false
+        end
+      end
+    end
+
+    def add_record(log_record)
+      raise UsageError, "You cannot add a record until the sink has been opened" unless @opened
+      raise UsageError, "You must supply a formatter" unless @formatter
+
+      message = @formatter.format_record(log_record)
+
+      pri = @log_level_map[log_record.log_level]
+      @mutex.synchronize { @syslog.log(pri, message) }
+    end
+
+  end
+end

vcap_logging/spec/unit/syslog_sink_spec.rb

@@ -0,0 +1,23 @@
+require File.join(File.dirname(__FILE__), '..', 'spec_helper')
+
+require 'syslog'
+
+describe VCAP::Logging::Sink::SyslogSink do
+  it 'should use the user facility for logging messages' do
+    Syslog.should_receive(:open).with('test', Syslog::LOG_CONS | Syslog::LOG_PID, Syslog::LOG_USER).and_return(nil)
+    sink = VCAP::Logging::Sink::SyslogSink.new('test')
+  end
+
+  it 'should map app log levels to syslog levels' do
+    msg = 'test message'
+    rec = mock(:test_record)
+    rec.should_receive(:log_level).and_return(:info)
+    fmt = mock(:test_formatter)
+    fmt.should_receive(:format_record).with(any_args()).and_return(msg)
+    Syslog.should_receive(:open).with('test', Syslog::LOG_CONS | Syslog::LOG_PID, Syslog::LOG_USER).and_return(Syslog)
+    Syslog.should_receive(:log).with(Syslog::LOG_INFO, msg).and_return(nil)
+    sink = VCAP::Logging::Sink::SyslogSink.new('test')
+    sink.formatter = fmt
+    sink.add_record(rec)
+  end
+end