feat: Retrieve request metadata from the server

Dockerfile

@@ -25,7 +25,9 @@ RUN apt-get update && apt-get install -y \
   libxss1 \
   libxtst6 \
   nodejs \
-  xdg-utils
+  xdg-utils \
+  libvulkan1 \
+  libu2f-udev
 
 # Install Chrome
 RUN wget --quiet https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb \
@@ -46,7 +48,7 @@ WORKDIR /app
 COPY .ruby-version grpc-web.gemspec Gemfile Gemfile.lock /app/
 COPY lib/grpc_web/version.rb /app/lib/grpc_web/
 
-RUN gem install bundler \
+RUN gem install bundler -v 2.3.26 \
  && bundle config --global frozen 1 \
  && bundle install -j4 --retry 3 \
  # Remove unneeded files (cached *.gem, *.o, *.c)

Gemfile.lock

@@ -8,22 +8,20 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    addressable (2.7.0)
-      public_suffix (>= 2.0.2, < 5.0)
-    apparition (0.1.0)
-      backports
-      capybara (~> 3.12, < 4)
+    addressable (2.8.1)
+      public_suffix (>= 2.0.2, < 6.0)
+    apparition (0.6.0)
+      capybara (~> 3.13, < 4)
       websocket-driver (>= 0.6.5)
     ast (2.4.0)
-    backports (3.15.0)
     byebug (11.0.1)
-    capybara (3.15.1)
+    capybara (3.35.3)
       addressable
       mini_mime (>= 0.1.3)
       nokogiri (~> 1.8)
       rack (>= 1.6.0)
       rack-test (>= 0.6.3)
-      regexp_parser (~> 1.2)
+      regexp_parser (>= 1.5, < 3.0)
       xpath (~> 3.2)
     coderay (1.1.2)
     crack (0.4.3)
@@ -40,10 +38,11 @@ GEM
     jaro_winkler (1.5.4)
     json (2.3.0)
     method_source (0.9.2)
-    mini_mime (1.0.2)
-    mini_portile2 (2.4.0)
-    nokogiri (1.10.8)
-      mini_portile2 (~> 2.4.0)
+    mini_mime (1.1.2)
+    mini_portile2 (2.6.1)
+    nokogiri (1.12.5)
+      mini_portile2 (~> 2.6.1)
+      racc (~> 1.4)
     parallel (1.19.1)
     parser (2.7.0.2)
       ast (~> 2.4.0)
@@ -53,15 +52,16 @@ GEM
     pry-byebug (3.7.0)
       byebug (~> 11.0)
       pry (~> 0.10)
-    public_suffix (4.0.1)
-    rack (2.0.9)
+    public_suffix (4.0.7)
+    racc (1.6.2)
+    rack (2.2.6.4)
     rack-cors (1.1.0)
       rack (>= 2.0.0)
-    rack-test (1.1.0)
-      rack (>= 1.0, < 3)
+    rack-test (2.1.0)
+      rack (>= 1.3)
     rainbow (3.0.0)
     rake (13.0.1)
-    regexp_parser (1.6.0)
+    regexp_parser (2.7.0)
     rspec (3.9.0)
       rspec-core (~> 3.9.0)
       rspec-expectations (~> 3.9.0)
@@ -96,9 +96,9 @@ GEM
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
       hashdiff (>= 0.4.0, < 2.0.0)
-    websocket-driver (0.7.1)
+    websocket-driver (0.7.5)
       websocket-extensions (>= 0.1.0)
-    websocket-extensions (0.1.4)
+    websocket-extensions (0.1.5)
     xpath (3.2.0)
       nokogiri (~> 1.8)
 
@@ -118,4 +118,4 @@ DEPENDENCIES
   webmock
 
 BUNDLED WITH
-   2.1.4
+   2.3.26

lib/grpc_web/grpc_web_call.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+module GRPCWeb
+  GRPCWebCall = Struct.new(
+    :request,
+    :metadata,
+    :metadata_received,
+    :metadata_sent,
+    :metadata_to_send,
+  )
+end
+

lib/grpc_web/server/grpc_request_decoder.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+class GRPCWeb::GRPCRequestDecoder
+
+  def self.decode(grpc_request)
+    text_coder = ::GRPCWeb::TextCoder
+    framing = ::GRPCWeb::RequestFraming
+    serialization = ::GRPCWeb::MessageSerialization
+
+    grpc_web_request = text_coder.decode_request(grpc_request)
+    grpc_web_request = framing.unframe_request(grpc_web_request)
+    serialization.deserialize_request(grpc_web_request)
+  end
+end

lib/grpc_web/server/grpc_request_processor.rb

@@ -6,38 +6,45 @@
 require 'grpc_web/server/error_callback'
 require 'grpc_web/server/message_serialization'
 require 'grpc_web/server/text_coder'
+require 'grpc_web/server/grpc_response_encoder'
+require 'grpc_web/server/grpc_request_decoder'
 
 # Placeholder
 module GRPCWeb::GRPCRequestProcessor
   class << self
     include ::GRPCWeb::ContentTypes
 
-    def process(grpc_web_request)
-      text_coder = ::GRPCWeb::TextCoder
-      framing = ::GRPCWeb::RequestFraming
-      serialization = ::GRPCWeb::MessageSerialization
-
-      grpc_web_request = text_coder.decode_request(grpc_web_request)
-      grpc_web_request = framing.unframe_request(grpc_web_request)
-      grpc_web_request = serialization.deserialize_request(grpc_web_request)
-      grpc_web_response = execute_request(grpc_web_request)
-      grpc_web_response = serialization.serialize_response(grpc_web_response)
-      grpc_web_response = framing.frame_response(grpc_web_response)
-      text_coder.encode_response(grpc_web_response)
+    def process(grpc_call)
+      encoder = GRPCWeb::GRPCResponseEncoder
+
+      grpc_web_response = execute_request(grpc_call)
+      encoder.encode(grpc_web_response)
     end
 
     private
 
-    def execute_request(request)
-      service_method = ::GRPC::GenericService.underscore(request.service_method.to_s)
+    def execute_request(grpc_call)
+      decoder = GRPCWeb::GRPCRequestDecoder
 
+      service_method = ::GRPC::GenericService.underscore(grpc_call.request.service_method.to_s)
       begin
-        response = request.service.send(service_method, request.body)
+        # Check arity to before passing in metadata to make sure that server can handle the request.
+        # This is to ensure backwards compatibility
+        if grpc_call.request.service.method(service_method.to_sym).arity == 1
+          response = grpc_call.request.service.send(
+            service_method,
+            decoder.decode(grpc_call.request).body,
+          )
+        else
+          response = grpc_call.request.service.send(
+            service_method, decoder.decode(grpc_call.request).body, grpc_call,
+          )
+        end
       rescue StandardError => e
-        ::GRPCWeb.on_error.call(e, request.service, request.service_method)
+        ::GRPCWeb.on_error.call(e, grpc_call.request.service, grpc_call.request.service_method)
         response = e # Return exception as body if one is raised
       end
-      ::GRPCWeb::GRPCWebResponse.new(response_content_type(request), response)
+      ::GRPCWeb::GRPCWebResponse.new(response_content_type(grpc_call.request), response)
     end
 
     # Use Accept header value if specified, otherwise use request content type

lib/grpc_web/server/grpc_response_encoder.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+class GRPCWeb::GRPCResponseEncoder
+
+  def self.encode(response)
+    text_coder = ::GRPCWeb::TextCoder
+    framing = ::GRPCWeb::RequestFraming
+    serialization = ::GRPCWeb::MessageSerialization
+
+    grpc_web_response = serialization.serialize_response(response)
+    grpc_web_response = framing.frame_response(grpc_web_response)
+    text_coder.encode_response(grpc_web_response)
+  end
+end

lib/grpc_web/server/rack_handler.rb

@@ -5,8 +5,10 @@
 require 'rack/request'
 require 'grpc_web/content_types'
 require 'grpc_web/grpc_web_request'
+require 'grpc_web/grpc_web_call'
 require 'grpc_web/server/error_callback'
 require 'grpc_web/server/grpc_request_processor'
+require "base64"
 
 # Placeholder
 module GRPCWeb::RackHandler
@@ -25,9 +27,20 @@ def call(service, service_method, env)
 
       content_type = rack_request.content_type
       accept = rack_request.get_header(ACCEPT_HEADER)
+      metadata = Hash[
+        *env.select { |k, _v| k.start_with? 'HTTP_' }
+            .reject { |k, _v| k.eql? ACCEPT_HEADER }
+            .collect { |k, v| [k.sub(/^HTTP_/, ''), v] }
+            .collect { |k, v| [k, k.end_with?('_BIN') ? Base64.decode64(v) : v] }
+            .collect { |k, v| [k.split('_').collect(&:downcase).join('_'), v] }
+            .sort
+            .flatten
+      ]
       body = rack_request.body.read
+
       request = GRPCWeb::GRPCWebRequest.new(service, service_method, content_type, accept, body)
-      response = GRPCWeb::GRPCRequestProcessor.process(request)
+      call = GRPCWeb::GRPCWebCall.new(request, metadata, started: false)
+      response = GRPCWeb::GRPCRequestProcessor.process(call)
 
       [200, { 'Content-Type' => response.content_type }, [response.body]]
     rescue Google::Protobuf::ParseError => e

spec/integration/ruby_server_js_client_spec.rb

@@ -115,7 +115,7 @@ def say_hello(_request, _metadata = nil)
     it 'makes a request using application/grpc-web-text content type' do
       expect(GRPCWeb::GRPCRequestProcessor).to \
         receive(:process) \
-        .with(have_attributes(content_type: 'application/grpc-web-text')) \
+        .with(have_attributes(request: have_attributes(content_type: 'application/grpc-web-text'))) \
         .and_call_original
       perform_request
     end
@@ -129,7 +129,7 @@ def say_hello(_request, _metadata = nil)
     it 'makes a request using application/grpc-web+proto content type' do
       expect(GRPCWeb::GRPCRequestProcessor).to \
         receive(:process) \
-        .with(have_attributes(content_type: 'application/grpc-web+proto')) \
+        .with(have_attributes(request: have_attributes(content_type: 'application/grpc-web+proto'))) \
         .and_call_original
       perform_request
     end

spec/unit/grpc_web/server/grpc_request_processor_spec.rb

@@ -2,9 +2,18 @@
 
 RSpec.describe ::GRPCWeb::GRPCRequestProcessor do
   describe '#process' do
-    subject(:process) { described_class.process(initial_request) }
+    subject(:process) { described_class.process(initial_call) }
 
-    let(:initial_request) { instance_double(::GRPCWeb::GRPCWebRequest) }
+    let(:initial_call) { instance_double(::GRPCWeb::GRPCWebCall, request: initial_request) }
+    let(:initial_request) do
+      instance_double(
+        ::GRPCWeb::GRPCWebRequest,
+        service_method: service_method,
+        service: service,
+        accept: request_accept,
+        content_type: request_content_type,
+      )
+    end
 
     let(:text_coder) { ::GRPCWeb::TextCoder }
     let(:framing) { ::GRPCWeb::RequestFraming }
@@ -57,9 +66,21 @@
       process
     end
 
-    it 'executes the request' do
-      expect(service).to receive(:say_hello).with(deserialized_request.body)
-      process
+    context 'when handler only accepts one parameter' do
+      before { allow(service).to receive(:method).and_return(instance_double(Method, arity: 1)) }
+
+      it 'executes the request' do
+        expect(service).to receive(:say_hello).with(deserialized_request.body)
+        process
+      end
+    end
+
+    context 'when handler accepts more than one parameter' do
+
+      it 'executes the request with additional metadata' do
+        expect(service).to receive(:say_hello).with(deserialized_request.body, initial_call)
+        process
+      end
     end
 
     describe 'execution response' do
@@ -116,6 +137,7 @@
 
       context 'when the service raises an error' do
         let(:error) { StandardError.new('something went wrong') }
+        let(:service) { instance_double(TestHelloService) }
 
         before { allow(service).to receive(:say_hello).and_raise(error) }
 

spec/unit/grpc_web/server/message_serialization_spec.rb

@@ -79,7 +79,7 @@
     end
     let(:body) { HelloRequest.new(name: 'Noa') }
 
-    shared_examples_for 'generates a body with a payload frame' do |expected_payload_frame_body:|
+    shared_examples_for 'generates a body with a payload frame' do |expected_payload_frame_body|
       it 'generates a body with a payload frame' do
         expect(serialized_response.body).to be_a(Array)
         expect(serialized_response.body.find(&:payload?).body).to eq expected_payload_frame_body
@@ -93,7 +93,7 @@
       end
     end
 
-    shared_examples_for 'generates a body with a header frame' do |expected_header_frame_body:|
+    shared_examples_for 'generates a body with a header frame' do |expected_header_frame_body|
       it 'generates a body with a header frame' do
         expect(serialized_response.body).to be_a(Array)
         expect(serialized_response.body.find(&:header?).body).to eq expected_header_frame_body
@@ -108,7 +108,6 @@
 
         it_behaves_like(
           'generates a body with a header frame',
-          expected_header_frame_body:
             "grpc-status:2\r\ngrpc-message:StandardError: I've made a huge mistake\r\n"\
             "x-grpc-web:1\r\n",
         )
@@ -121,7 +120,6 @@
 
         it_behaves_like(
           'generates a body with a header frame',
-          expected_header_frame_body:
             "grpc-status:5\r\ngrpc-message:Where am I?\r\nx-grpc-web:1\r\nuser-role-id:123\r\n",
         )
       end
@@ -132,11 +130,11 @@
 
       it_behaves_like(
         'generates a body with a payload frame',
-        expected_payload_frame_body: '{"name":"Noa"}',
+        '{"name":"Noa"}',
       )
       it_behaves_like(
         'generates a body with a header frame',
-        expected_header_frame_body: "grpc-status:0\r\ngrpc-message:OK\r\nx-grpc-web:1\r\n",
+        "grpc-status:0\r\ngrpc-message:OK\r\nx-grpc-web:1\r\n",
       )
 
       it_behaves_like 'serializes an exception'
@@ -147,11 +145,11 @@
 
       it_behaves_like(
         'generates a body with a payload frame',
-        expected_payload_frame_body: "\n\x03Noa",
+         "\n\x03Noa",
       )
       it_behaves_like(
         'generates a body with a header frame',
-        expected_header_frame_body: "grpc-status:0\r\ngrpc-message:OK\r\nx-grpc-web:1\r\n",
+         "grpc-status:0\r\ngrpc-message:OK\r\nx-grpc-web:1\r\n",
       )
 
       it_behaves_like 'serializes an exception'