Incorporate uaparser feedback, make flatjar work.

* Handle running inside a flatjar. (technique taken from geoip filter)
* Rename field/container to source/target
* Allow target to be an existing hash in which case data is merged
* Better comments
* Allow arrays for input (though only parse the first element)
* s/'/"/ and add parens to function calles
* Changelog entry

CHANGELOG

@@ -16,6 +16,8 @@
     warn you if you use it. (LOGSTASH-803)
   - feature: grok: Adds tag_on_failure setting so you can prevent grok from
     tagging events on failure. (#328, patch by Neil Prosser)
+  - new: uaparser: parses user agent strings in to structured data based on
+    BrowserScope data (#347, patch by Dan Everton)
 
   ## outputs
   - fix bug in mongo output that would fail to load bson_java support

Makefile

@@ -208,6 +208,7 @@ build/flatgems: | build vendor/bundle
 	@# all the gem specs.
 	rsync -av $(VENDOR_DIR)/gems/jruby-openssl-*/lib/shared/jopenssl.jar $@/lib
 	rsync -av $(VENDOR_DIR)/gems/sys-uname-*/lib/unix/ $@/lib
+	rsync -av $(VENDOR_DIR)/gems/user_agent_parser-*/vendor/ua-parser $@/vendor
 
 flatjar-test:
 	GEM_HOME= GEM_PATH= java -jar build/logstash-$(VERSION)-flatjar.jar rspec $(TESTS)
@@ -227,7 +228,7 @@ flatjar: build/logstash-$(VERSION)-flatjar.jar
 build/jar: | build build/flatgems build/monolith
 	$(QUIET)mkdir build/jar
 	$(QUIET)rsync -av --delete build/flatgems/lib/ build/monolith/ build/ruby/ patterns build/jar/
-	$(QUIET)rsync -av --delete build/flatgems/data build/jar/
+	$(QUIET)rsync -av --delete build/flatgems/data build/flatgems/vendor build/jar/
 	$(QUIET)(cd lib; rsync -av --delete logstash/web/public ../build/jar/logstash/web/public)
 	$(QUIET)(cd lib; rsync -av --delete logstash/web/views ../build/jar/logstash/web/views)
 	$(QUIET)(cd lib; rsync -av --delete logstash/certs ../build/jar/logstash/certs)

lib/logstash/filters/uaparser.rb

@@ -1,62 +1,87 @@
 require "logstash/filters/base"
 require "logstash/namespace"
+require "tempfile"
 
-# This filter can parse user agent strings in to structured data
+# Parse user agent strings into structured data based on BrowserScope data
+#
+# UserAgent filter, adds information about user agent like family, operating
+# system, version, and device
+#
+# Logstash releases ship with the regexes.yaml database made available from
+# ua-parser with an Apache 2.0 license. For more details on ua-parser, see
+# <https://github.com/tobie/ua-parser/>.
 class LogStash::Filters::UAParser < LogStash::Filters::Base
   config_name "uaparser"
   plugin_status "experimental"
 
-  # The field containing the user agent string to parse
-  config :field, :validate => :string
+  # The field containing the user agent string. If this field is an
+  # array, only the first value will be used.
+  config :source, :validate => :string, :required => true
 
   # The name of the field to assign the UA data hash to
-  config :container, :validate => :string, :default => "ua"
+  config :target, :validate => :string, :default => "ua"
 
-  # name with full path of BrowserScope YAML file.
-  # One is shipped with this filter, but you can reference
-  # updated versions here. See https://github.com/tobie/ua-parser
-  # for updates
-  config :regexes_path, :validate => :string
+  # regexes.yaml file to use
+  #
+  # If not specified, this will default to the regexes.yaml that ships
+  # with logstash.
+  config :regexes, :validate => :string
 
   public
   def register
     require 'user_agent_parser'
-
-    if @regexes_path.nil?
-        @parser = UserAgentParser::Parser.new
+    if @regexes.nil?
+      begin
+        @parser = UserAgentParser::Parser.new()
+      rescue Exception => e
+        begin
+          # Running from a flatjar which has a different layout
+          jar_path = [__FILE__.split("!").first, "/vendor/ua-parser/regexes.yaml"].join("!")
+          tmp_file = Tempfile.new('logstash-uaparser-regexes')
+          tmp_file.write(File.read(jar_path))
+          tmp_file.close # this file is reaped when ruby exits
+          @parser = UserAgentParser::Parser.new(tmp_file.path)
+        rescue => ex
+          raise "Failed to cache, due to: #{ex}\n#{ex.backtrace}"
+        end
+      end
     else
-        @logger.info? and @logger.info "Using regexes from",  :regexes_path => @regexes_path
-        @parser = UserAgentParser::Parser.new(regexes_path)
+      @logger.info("Using user agent regexes", :regexes => @regexes)
+      @parser = UserAgentParser::Parser.new(@regexes)
     end
   end #def register
 
   public
   def filter(event)
     return unless filter?(event)
+    ua_data = nil
 
-    result = @parser.parse event[@field]
+    useragent = event[@source]
+    useragent = useragent.first if useragent.is_a? Array
 
-    ua = {}
-    ua['name'] = result.name
-
-    if not result.os.nil?
-      ua['os'] = result.os
+    begin
+      ua_data = @parser.parse(useragent)
+    rescue Exception => e
+      @logger.error("Uknown error while parsing user agent data", :exception => e, :field => @source, :event => event)
     end
 
-    if not result.device.nil?
-      ua['device'] = result.device
+    unless ua_data.nil?
+        event[@target] = {} if event[@target].nil?
+
+        event[@target]["name"] = ua_data.name
+        event[@target]["os"] = ua_data.os if not ua_data.os.nil?
+        event[@target]["device"] = ua_data.device if not ua_data.device.nil?
+
+        if not ua_data.version.nil?
+          ua_version = ua_data.version
+
+          event[@target]["major"] = ua_version.major
+          event[@target]["minor"] = ua_version.minor
+        end
+
+      filter_matched(event)
     end
 
-    if not result.version.nil?
-      ua_version = result.version
-
-      ua['major'] = ua_version.major
-      ua['minor'] = ua_version.minor
-    end
-
-    event[@container] = ua
-
-    filter_matched(event)
   end # def filter
 end # class LogStash::Filters::UAParser