zipkin-query gem

Split access to Zipkin Query service out into separate gem
- Fix generated ruby namespacing in `zipkin-thrift`
- Thrift files are symlinked in `zipkin-gems/zipkin-query/thrift`, and
  the generated code is in `zipkin-gems/zipkin-query/vendor`

Author: franklinhu
Pull Request: #19
URL: #19

zipkin-gems/zipkin-query/Rakefile

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+# 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-query.gemspec"
+end

zipkin-gems/zipkin-query/lib/zipkin-query.rb

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+# 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.
+
+gen_rb_path = File.expand_path(File.dirname(__FILE__) + "/../vendor/gen-rb")
+$LOAD_PATH.unshift gen_rb_path
+$LOAD_PATH.unshift "#{gen_rb_path}/zipkin-query"
+
+require "#{gen_rb_path}/zipkin-query"
+
+module ZipkinQuery extend self
+
+  module Client
+    # The node location in zookeeper that stores the cassandra location
+    NODE_PATH = "/twitter/service/zipkin/query"
+
+    def self.with_transport(opts = {})
+      # Open a connection to a thrift server, do something, and close the connection
+
+      begin
+
+        if opts[:use_local_server]
+          # If we're running local (development mode) return a set value
+          host = "localhost"
+          port = 9149
+
+          # Create the connection to the local b3 query_daemon which uses different
+          # transport mechanism
+          socket = Thrift::Socket.new(host, port)
+          transport = Thrift::BufferedTransport.new(socket)
+        else
+          # Get the host and port of the location of the query service from zookeeper
+          zk_host = opts[:zk_host] || "localhost"
+          zk_port = opts[:zk_port] || 2181
+
+          host, port = Client::get_query_service(zk_host, zk_port, opts)
+
+          # Create the connection to the b3 query_daemon
+          socket = Thrift::Socket.new(host, port)
+          buffered_tp = Thrift::BufferedTransport.new(socket)
+          transport = Thrift::FramedTransport.new(buffered_tp)
+        end
+
+        protocol = Thrift::BinaryProtocol.new(transport)
+        client = ThriftClient.new(Zipkin::ZipkinQuery::Client, host + ':' + port.to_s, :retries => 0, :timeout => 60)
+
+        # set up tracing for the client we use to talk to the query daemon
+        client_id = FinagleThrift::ClientId.new(:name => "zipkin.prod")
+        FinagleThrift.enable_tracing!(client, client_id, "zipkin")
+
+        begin
+          transport.open
+          yield(client)
+        ensure
+          transport.close
+        end
+      rescue ZookeeperExceptions::ZookeeperException::ConnectionClosed => ze
+        "Could not connect to zookeeper at #{opts[:zk_host]}:#{opts[:zk_port]}"
+      end
+
+    end
+
+    def self.get_query_service(zk_host, zk_port, opts={})
+      # Takes either:
+      # - ZooKeeper config options that map to a Zipkin Query server set OR
+      # - Direct host/port of a Query daemon
+
+      if opts[:skip_zookeeper]
+        return [ opts[:zipkin_query_host], opts[:zipkin_query_port] ]
+      end
+
+      node_path = opts[:node_path] || NODE_PATH
+
+      # TODO: throw error if it fails
+      zk = Zookeeper.new("#{zk_host}:#{zk_port}")
+
+      begin
+        # TODO: handle errors here
+        children = zk.get_children(:path => node_path)
+        node_key = children[:children][0]
+
+        # TODO: throw errors
+        node = zk.get(:path => "#{node_path}/#{node_key}")
+      ensure
+        zk.close() if zk
+      end
+
+      # Deserialize the result
+      d = Thrift::Deserializer.new
+      si = d.deserialize(Twitter::Thrift::ServiceInstance.new, node[:data])
+
+      # Return the host and port
+      [si.serviceEndpoint.host, si.serviceEndpoint.port]
+    end
+  end
+
+end

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

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+# 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 ZipkinQuery
+  VERSION = "0.0.1"
+end

zipkin-gems/zipkin-query/thrift/zipkinCore.thrift

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+../../../zipkin-thrift/src/main/thrift/zipkinCore.thrift

zipkin-gems/zipkin-query/thrift/zipkinQuery.thrift

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+../../../zipkin-thrift/src/main/thrift/zipkinQuery.thrift

zipkin-gems/zipkin-query/vendor/gen-rb/zipkin-query.rb

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+# 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 'set'
+require 'thrift'
+
+module ZipkinQuery
+  require 'zipkin-query/zipkin_query'
+end