Add prefix for X-Opaque-Id on initializer

Author: picandocodigo

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

@@ -87,6 +87,8 @@ 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
       #
       # @yield [faraday] Access and configure the `Faraday::Connection` instance directly with a block
       #
@@ -114,6 +116,7 @@ def initialize(arguments={}, &block)
                                      DEFAULT_HOST)
 
         @send_get_body_as = @arguments[:send_get_body_as] || 'GET'
+        @opaque_id_prefix = @arguments[:opaque_id_prefix] || nil
 
         if @arguments[:request_timeout]
           @arguments[:transport_options][:request] = { timeout: @arguments[:request_timeout] }
@@ -148,7 +151,8 @@ def perform_request(method, path, params = {}, body = nil, headers = nil)
         method = @send_get_body_as if 'GET' == method && body
         if @opaque_id
           headers = {} if headers.nil?
-          headers.merge!('X-Opaque-Id' => @opaque_id)
+          opaque_id = @opaque_id_prefix ? "#{@opaque_id_prefix}#{@opaque_id}" : @opaque_id
+          headers.merge!('X-Opaque-Id' => opaque_id)
           @opaque_id = nil # Remove Opaque id after each request
         end
         transport.perform_request(method, path, params, body, headers)

elasticsearch-transport/spec/elasticsearch/transport/client_spec.rb

@@ -667,6 +667,24 @@
         expect(client.perform_request('GET', '/').headers).not_to include('x-opaque-id')
       end
     end
+
+    context 'when an x-opaque-id prefix is set on initialization' do
+      let(:prefix) { 'elastic_cloud' }
+      let(:client) do
+        described_class.new(host: hosts, opaque_id_prefix: prefix)
+      end
+
+      it 'uses x-opaque-id on a request' do
+        client.opaque_id = '12345'
+        expect(client.perform_request('GET', '/').headers['x-opaque-id']).to eq("#{prefix}12345")
+      end
+
+      it 'deletes x-opaque-id on a second request' do
+        client.opaque_id = 'asdfg'
+        expect(client.perform_request('GET', '/').headers['x-opaque-id']).to eq("#{prefix}_asdfg")
+        expect(client.perform_request('GET', '/').headers).not_to include('x-opaque-id')
+      end
+    end
   end
 
   context 'when the client connects to Elasticsearch' do