[CLIENT] Adds meta header

Author: picandocodigo

elasticsearch-transport/lib/elasticsearch/transport/client.rb

@@ -120,8 +120,11 @@ class Client
       #
       # @option api_key [String, Hash] :api_key Use API Key Authentication, either the base64 encoding of `id` and `api_key`
       #                                         joined by a colon as a String, or a hash with the `id` and `api_key` values.
-      # @option opaque_id_prefix [String] :opaque_id_prefix set a prefix for X-Opaque-Id when initializing the client. This
-      # will be prepended to the id you set before each request if you're using X-Opaque-Id
+      # @option opaque_id_prefix [String] :opaque_id_prefix set a prefix for X-Opaque-Id when initializing the client.
+      #                                                     This will be prepended to the id you set before each request
+      #                                                     if you're using X-Opaque-Id
+      # @option enable_meta_header [Boolean] :enable_meta_header Enable sending the meta data header to Cloud.
+      #                                                          (Default: true)
       #
       # @yield [faraday] Access and configure the `Faraday::Connection` instance directly with a block
       #
@@ -136,9 +139,11 @@ def initialize(arguments={}, &block)
         @arguments[:randomize_hosts]    ||= false
         @arguments[:transport_options]  ||= {}
         @arguments[:http]               ||= {}
+        @arguments[:enable_meta_header] ||= true
         @options[:http]                 ||= {}
 
         set_api_key if (@api_key = @arguments[:api_key])
+        set_meta_header unless @arguments[:enable_meta_header] == false
 
         @seeds = extract_cloud_creds(@arguments)
         @seeds ||= __extract_hosts(@arguments[:hosts] ||
@@ -186,13 +191,40 @@ def perform_request(method, path, params = {}, body = nil, headers = nil)
 
       def set_api_key
         @api_key = __encode(@api_key) if @api_key.is_a? Hash
+        add_header('Authorization' => "ApiKey #{@api_key}")
+        @arguments.delete(:user)
+        @arguments.delete(:password)
+      end
+
+      def add_header(header)
         headers = @arguments[:transport_options]&.[](:headers) || {}
-        headers.merge!('Authorization' => "ApiKey #{@api_key}")
+        headers.merge!(header)
         @arguments[:transport_options].merge!(
           headers: headers
         )
-        @arguments.delete(:user)
-        @arguments.delete(:password)
+      end
+
+      def set_meta_header
+        meta_headers = {
+          es: Elasticsearch::VERSION,
+          rb: RUBY_VERSION,
+          t: Elasticsearch::Transport::VERSION
+        }
+        meta_headers.merge!(meta_header_engine) if meta_header_engine
+        add_header({ 'x-elastic-client-meta' => meta_headers.map { |k, v| "#{k}=#{v}" }.join(',') })
+      end
+
+      def meta_header_engine
+        case RUBY_ENGINE
+        when 'ruby'
+          {}
+        when 'jruby'
+          { jr: JRUBY_VERSION }
+        when 'rbx'
+          { rbx: RUBY_VERSION }
+        else
+          { RUBY_ENGINE.to_sym => RUBY_VERSION }
+        end
       end
 
       def extract_cloud_creds(arguments)

elasticsearch-transport/spec/elasticsearch/transport/meta_header_spec.rb

@@ -0,0 +1,73 @@
+# Licensed to Elasticsearch B.V. under one or more contributor
+# license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright
+# ownership. Elasticsearch B.V. licenses this file to you 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 'spec_helper'
+
+describe Elasticsearch::Transport::Client do
+  context 'meta-header' do
+    let(:client) do
+      described_class.new.tap do |klient|
+        allow(klient).to receive(:__build_connections)
+      end
+    end
+    let(:subject) { client.transport.connections.first.connection.headers }
+    let(:regexp) { /^[a-z]{1,}=[a-z0-9.\-]{1,}(?:,[a-z]{1,}=[a-z0-9.\-]+)*$/ }
+    let(:meta_header) do
+      if RUBY_ENGINE == 'jruby'
+        "es=#{Elasticsearch::VERSION},rb=#{RUBY_VERSION},t=#{Elasticsearch::Transport::VERSION},jr=#{JRUBY_VERSION}"
+      else
+        "es=#{Elasticsearch::VERSION},rb=#{RUBY_VERSION},t=#{Elasticsearch::Transport::VERSION}"
+      end
+    end
+
+    context 'single use of meta header' do
+      it 'x-elastic-client-header value matches regexp' do
+        expect(subject['x-elastic-client-meta']).to match(regexp)
+        expect(subject).to include('x-elastic-client-meta' => meta_header)
+      end
+    end
+
+    context 'when using user-agent headers' do
+      let(:client) do
+        transport_options = { headers: { user_agent: 'My Ruby App' } }
+        described_class.new(transport_options: transport_options).tap do |klient|
+          allow(klient).to receive(:__build_connections)
+        end
+      end
+
+      it 'is friendly to previously set headers' do
+        expect(subject).to include(user_agent: 'My Ruby App')
+        expect(subject).to include('x-elastic-client-meta' => meta_header)
+      end
+    end
+
+    context 'when using API Key' do
+      let(:client) do
+        described_class.new(api_key: 'an_api_key')
+      end
+
+      let(:authorization_header) do
+        client.transport.connections.first.connection.headers['Authorization']
+      end
+
+      it 'Adds the ApiKey header to the connection' do
+        expect(authorization_header).to eq('ApiKey an_api_key')
+        expect(subject['x-elastic-client-meta']).to match(regexp)
+      end
+    end
+  end
+end