[CLIENT] Addresses custom headers on initialization

Related: #1428, #1426

Author: picandocodigo

elasticsearch-transport/lib/elasticsearch/transport/transport/http/manticore.rb

@@ -63,6 +63,7 @@ class Manticore
           include Base
 
           def initialize(arguments={}, &block)
+            @request_options = { headers: (arguments.dig(:transport_options, :headers) || {}) }
             @manticore = build_client(arguments[:options] || {})
             super(arguments, &block)
           end
@@ -109,7 +110,6 @@ def perform_request(method, path, params={}, body=nil, headers=nil, opts={})
           # @return [Connections::Collection]
           #
           def __build_connections
-            @request_options = {}
             apply_headers(@request_options, options[:transport_options])
             apply_headers(@request_options, options)
 
@@ -155,11 +155,11 @@ def host_unreachable_exceptions
           private
 
           def apply_headers(request_options, options)
-            headers = (options && options[:headers]) || {}
+            headers = options&.[](:headers) || {}
             headers[CONTENT_TYPE_STR] = find_value(headers, CONTENT_TYPE_REGEX) || DEFAULT_CONTENT_TYPE
             headers[USER_AGENT_STR] = find_value(headers, USER_AGENT_REGEX) || user_agent_header
             headers[ACCEPT_ENCODING] = GZIP if use_compression?
-            request_options.merge!(headers: headers)
+            request_options[:headers].merge!(headers)
           end
 
           def user_agent_header

elasticsearch-transport/test/unit/transport_manticore_test.rb

@@ -184,7 +184,7 @@ def common_headers
 
               should 'allow to set options for Manticore' do
                 options = { headers: { 'User-Agent' => 'myapp-0.0' } }
-                transport = Manticore.new hosts: [{ host: 'foobar', port: 1234 }], options: options
+                transport = Manticore.new(hosts: [{ host: 'foobar', port: 1234 }], options: options)
                 transport.connections.first.connection
                   .expects(:get)
                   .with do |_host, _options|
@@ -209,13 +209,35 @@ def common_headers
                 transport = Manticore.new hosts: [{ host: 'foobar', port: 1234 }], options: options
               end
 
+              should 'allow custom headers' do
+                transport_options = { headers: { 'Authorization' => 'Basic token' } }
+                transport = Manticore.new(
+                  hosts: [{ host: 'foobar', port: 1234 }],
+                  transport_options: transport_options
+                )
+
+                assert_equal(
+                  transport.instance_variable_get(:@request_options)[:headers]['Authorization'],
+                  'Basic token'
+                )
+                transport.connections.first.connection
+                  .expects(:get)
+                  .with do |_host, _options|
+                  assert_equal('Basic token', _options[:headers]['Authorization'])
+                  true
+                end
+                  .returns(stub_everything)
+
+                transport.perform_request('GET', '/', {})
+              end
+
               should 'pass :transport_options to Manticore::Client' do
                 options = {
                   transport_options: { potatoes: 1 }
                 }
 
                 ::Manticore::Client.expects(:new).with(potatoes: 1, ssl: {})
-                transport = Manticore.new hosts: [{ host: 'foobar', port: 1234 }], options: options
+                transport = Manticore.new(hosts: [{ host: 'foobar', port: 1234 }], options: options)
               end
             end
           end