zipkin-tracer gem

Add tracing to a Rack application

- In config.ru: `use ZipkinTracer::RackHandler`
- Configurable in Rails configs

Author: franklinhu
Pull Request: #13
URL: #13

README.md

@@ -143,6 +143,17 @@ The UI is a standard Rails 3 app.
   bundle exec rails server.
 ```
 
+#### zipkin-tracer gem
+The `zipkin-tracer` gem adds tracing to a Rails application through the use of a Rack Handler.
+In `config.ru`:
+
+```
+  use ZipkinTracer::RackHandler
+  run <YOUR_APPLICATION>
+```
+
+If the application's static assets are served through Rails, those requests will be traced.
+
 ## Running a Hadoop job
 It's possible to setup Scribe to log into Hadoop. If you do this you can generate various reports from the data
 that is not easy to do on the fly in Zipkin itself.

zipkin-gems/zipkin-tracer/Rakefile

@@ -0,0 +1,19 @@
+# Copyright 2012 Twitter Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+require 'rubygems'
+
+desc 'Build the gem'
+task :build do
+  system "gem build zipkin-tracer.gemspec"
+end

zipkin-gems/zipkin-tracer/lib/zipkin-tracer.rb

@@ -0,0 +1,79 @@
+# Copyright 2012 Twitter Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+require 'finagle-thrift'
+require 'finagle-thrift/trace'
+require 'scribe'
+
+require 'zipkin-tracer/careless_scribe'
+
+module ZipkinTracer extend self
+
+  class RackHandler
+    def initialize(app)
+      @app = app
+      @lock = Mutex.new
+
+      config = app.config.zipkin_tracer
+      @service_name = config[:service_name]
+      @service_port = config[:service_port]
+
+      scribe =
+        if config[:scribe_server] then
+          Scribe.new(config[:scribe_server])
+        else
+          Scribe.new()
+        end
+
+      scribe_max_buffer =
+        if config[:scribe_max_buffer] then
+          config[:scribe_max_buffer]
+        else
+          10
+        end
+
+      @sample_rate =
+        if config[:sample_rate] then
+          config[:sample_rate]
+        else
+          0.1
+        end
+
+      ::Trace.tracer = ::Trace::ZipkinTracer.new(CarelessScribe.new(scribe), scribe_max_buffer)
+    end
+
+    def call(env)
+      id = ::Trace::TraceId.new(::Trace.generate_id, nil, ::Trace.generate_id, true)
+      ::Trace.default_endpoint = ::Trace.default_endpoint.with_service_name(@service_name).with_port(@service_port)
+      ::Trace.sample_rate=(@sample_rate)
+      tracing_filter(id, env) { @app.call(env) }
+    end
+
+    private
+    def tracing_filter(trace_id, env)
+      @lock.synchronize do
+        ::Trace.push(trace_id)
+        ::Trace.set_rpc_name(env["REQUEST_METHOD"]) # get/post and all that jazz
+        ::Trace.record(::Trace::BinaryAnnotation.new("http.uri", env["PATH_INFO"], "STRING", ::Trace.default_endpoint))
+        ::Trace.record(::Trace::Annotation.new(::Trace::Annotation::SERVER_RECV, ::Trace.default_endpoint))
+      end
+      yield if block_given?
+    ensure
+      @lock.synchronize do
+        ::Trace.record(::Trace::Annotation.new(::Trace::Annotation::SERVER_SEND, ::Trace.default_endpoint))
+        ::Trace.pop
+      end
+    end
+  end
+
+end

zipkin-gems/zipkin-tracer/lib/zipkin-tracer/version.rb

@@ -0,0 +1,17 @@
+# Copyright 2012 Twitter Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+module ZipkinTracer
+  VERSION = "0.0.1"
+end
+

zipkin-gems/zipkin-tracer/zipkin-tracer.gemspec

@@ -0,0 +1,36 @@
+# -*- encoding: utf-8 -*-
+# Copyright 2012 Twitter Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+lib = File.expand_path('../lib/', __FILE__)
+$:.unshift lib unless $:.include?(lib)
+
+require 'zipkin-tracer/version'
+
+Gem::Specification.new do |s|
+  s.name                      = "zipkin-tracer"
+  s.version                   = ZipkinTracer::VERSION
+  s.authors                   = ["Franklin Hu"]
+  s.email                     = ["[email protected]"]
+  s.homepage                  = "https://github.com/twitter/zipkin"
+  s.summary                   = "Ruby tracing via Zipkin"
+  s.description               = "Adds tracing instrumentation for ruby applications"
+
+  s.required_rubygems_version = ">= 1.3.5"
+
+  s.files                     = Dir.glob("{bin,lib}/**/*")
+  s.require_path              = 'lib'
+
+  s.add_dependency "finagle-thrift", "~> 1.2.0"
+  s.add_dependency "scribe", "~> 0.2.4"
+end

zipkin-web/Gemfile

@@ -6,4 +6,5 @@ gem 'thrift_client', "0.6.3"
 gem 'zookeeper', "1.2.4"
 gem 'finagle-thrift', '1.2.0'
 gem 'scribe', '0.2.4'
+gem 'zipkin-tracer', '0.0.1'
 

zipkin-web/Gemfile.lock

@@ -88,6 +88,9 @@ GEM
       polyglot
       polyglot (>= 0.3.1)
     tzinfo (0.3.33)
+    zipkin-tracer (0.0.1)
+      finagle-thrift (~> 1.2.0)
+      scribe (~> 0.2.4)
     zookeeper (1.2.4)
       backports (~> 2.5.1)
       logging (~> 1.7.2)
@@ -101,4 +104,5 @@ DEPENDENCIES
   scribe (= 0.2.4)
   thrift (= 0.6.0)
   thrift_client (= 0.6.3)
+  zipkin-tracer (= 0.0.1)
   zookeeper (= 1.2.4)

zipkin-web/config.ru

@@ -1,11 +1,11 @@
 # Copyright 2012 Twitter Inc.
-# 
+#
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
-# 
+#
 #      http://www.apache.org/licenses/LICENSE-2.0
-# 
+#
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -15,5 +15,5 @@
 # This file is used by Rack-based servers to start the application.
 
 require ::File.expand_path('../config/environment',  __FILE__)
-use ZipkinRackHandler
+use ZipkinTracer::RackHandler
 run Zipkin::Application

zipkin-web/config/application.rb

@@ -21,7 +21,6 @@
 require "action_mailer/railtie"
 require "active_resource/railtie"
 require "rails/test_unit/railtie"
-require 'lib/careless_scribe'
 require 'sprockets/railtie'
 
 # If you have a Gemfile, require the gems listed there, including any gems
@@ -88,43 +87,17 @@ class Application < Rails::Application
     #   :skip_zookeeper      => true
     #}
 
-  end
-end
+    config.zipkin_tracer = {
+        # Scribe settings that can be overwritten
+        #:scribe_server => "HOST:PORT",
+        #:scribe_max_buff => 10
 
-class ZipkinRackHandler
-  def initialize(app)
-    @app = app
-    @lock = Mutex.new
-    Trace.tracer = Trace::ZipkinTracer.new(CarelessScribe.new(Scribe.new()), 10)
-  end
+        # Required settings
+        :service_name => "ZipkinUI",
+        :service_port => 80,
 
-  def call(env)
-    # TODO HERE BE HACK. Chad made me do it!
-    # this is due to our setup where statics are served through the ruby app, but we don't want to trace that.
-    rp = env["REQUEST_PATH"]
-    if !rp.blank? && (rp.starts_with?("/stylesheets") || rp.starts_with?("/javascripts") || rp.starts_with?("/images"))
-      return @app.call(env)
-    end
-
-    id = Trace::TraceId.new(Trace.generate_id, nil, Trace.generate_id, true)
-    Trace.default_endpoint = Trace.default_endpoint.with_service_name("zipkinui").with_port(0) #TODO any way to get the port?
-    Trace.sample_rate=(1)
-    tracing_filter(id, env) { @app.call(env) }
-  end
+        :sample_rate => 1
+    }
 
-  private
-  def tracing_filter(trace_id, env)
-    @lock.synchronize do
-      Trace.push(trace_id)
-      Trace.set_rpc_name(env["REQUEST_METHOD"]) # get/post and all that jazz
-      Trace.record(Trace::BinaryAnnotation.new("http.uri", env["PATH_INFO"], "STRING", Trace.default_endpoint))
-      Trace.record(Trace::Annotation.new(Trace::Annotation::SERVER_RECV, Trace.default_endpoint))
-    end
-    yield if block_given?
-  ensure
-    @lock.synchronize do
-      Trace.record(Trace::Annotation.new(Trace::Annotation::SERVER_SEND, Trace.default_endpoint))
-      Trace.pop
-    end
   end
 end