Add client for stencil to get file set descriptor

Author: davalpargal

clients/ruby/Gemfile

@@ -7,10 +7,13 @@ gemspec
 
 gem "rake", "~> 13.0"
 gem "http", "4.4.1"
+gem 'concurrent-ruby', require: 'concurrent'
+gem 'protobuf'
 
 group :test do
   gem "simplecov", ">= 0.9"
   gem "rspec", "~> 3.0"
   gem "rubocop", "~> 1.7"
   gem "pry"
+  gem "google-protobuf"
 end

clients/ruby/lib/stencil.rb

@@ -1,7 +1,16 @@
-require "stencil/version"
-require "stencil/configuration"
-require "stencil/constants"
+require_relative "stencil/version"
+require_relative "stencil/configuration"
+require_relative "stencil/constants"
+require_relative "stencil/client"
+
+require "http"
+require "concurrent"
+require "protobuf"
 
 module Stencil
   class Error < StandardError; end
+  class InvalidConfiguration < Error; end
+  class InvalidProtoClass < Error; end
+  class HTTPClientError < Error; end
+  class HTTPServerError < Error; end
 end

clients/ruby/lib/stencil/client.rb

@@ -0,0 +1,48 @@
+module Stencil
+  class Client
+    attr_reader :root
+    def initialize
+      begin
+        @config = Stencil.configuration
+        validate_configuration(@config)
+        @root = nil
+        setup_http_client
+        load_descriptors
+      end
+    end
+
+    def get_type(proto_name)
+      @root.file.each do |file_desc|
+        file_desc.message_type.each do |message|
+          if proto_name == "#{file_desc.options.java_package}.#{message.name}"
+            return message
+          end
+        end
+      end
+      raise InvalidProtoClass.new
+    end
+
+    private
+
+    def validate_configuration(configuration)
+      raise Stencil::InvalidConfiguration.new() if configuration.registry_url.nil? || configuration.bearer_token.nil? || configuration.bearer_token == "Bearer "
+    end
+
+    def setup_http_client
+      @http_client = HTTP.auth(@config.bearer_token).timeout(@config.http_timeout)
+    end
+
+    def load_descriptors
+      begin
+        response = @http_client.get(@config.registry_url)
+        if response.code != 200
+          raise HTTPServerError.new("Error while fetching descriptor file: Got #{response.code} from stencil server")
+        end
+      rescue StandardError => e
+        raise HTTPClientError.new(e.message)
+      end
+
+      @root = Google::Protobuf::FileDescriptorSet.decode(response.body)
+    end
+  end
+end

clients/ruby/lib/stencil/configuration.rb

@@ -4,12 +4,12 @@ def initialize
       @config = ::OpenStruct.new
     end
 
-    def registry_urls
-      @config.registry_urls || []
+    def registry_url
+      @config.registry_url
     end
 
-    def registry_urls=(registry_urls)
-      @config.registry_urls = registry_urls
+    def registry_url=(registry_url)
+      @config.registry_url = registry_url
     end
 
     def http_timeout

clients/ruby/spec/data/desc-proto-bin

@@ -16,6 +16,7 @@
 
 require 'pry'
 require 'stencil'
+require 'webmock/rspec'
 
 RSpec.configure do |config|
   config.filter_run_when_matching focus: true
@@ -24,11 +25,4 @@
   config.order = :random
 end
 
-module JSON
-  module_function
-
-  def reader(file_name)
-    path = File.join(File.dirname(__FILE__), "test_data/#{file_name}")
-    File.read(path)
-  end
-end
+WebMock.disable_net_connect!(allow_localhost: true)

clients/ruby/spec/spec_helper.rb

@@ -0,0 +1,68 @@
+module Stencil
+  RSpec.describe Client do
+    let(:registry_url) { 'http://stencil.test' }
+    let(:bearer_token) { 'sample-token-123' }
+    let(:service_type_message)  do
+      service_type = nil
+      Google::Protobuf::FileDescriptorSet.decode(File.read('spec/data/desc-proto-bin')).file.each do |file|
+        file.message_type.each do |msg|
+          if msg.name == "ServiceType"
+            service_type = msg
+          end
+        end
+      end
+      service_type
+    end
+
+    context '#get_type' do
+      subject { Stencil::Client.new }
+
+      before(:each) do
+        Stencil.configure do |config|
+          config.registry_url = registry_url
+          config.bearer_token = bearer_token
+        end
+
+        @stencil_get_stub = stub_request(:get, registry_url).
+          with(
+            headers: {
+              'Authorization' => 'Bearer ' + bearer_token,
+              'Connection' => 'close',
+              'Host' => 'stencil.test',
+              'User-Agent' => 'http.rb/4.4.1'
+            })
+      end
+
+      it 'should raise error if configs are invalid' do
+        config = Stencil.configuration
+        config.bearer_token = ""
+        expect { subject }.to raise_error(Stencil::InvalidConfiguration)
+      end
+
+      it 'should raise error if http client returns error on stencil get api' do
+        @stencil_get_stub.to_raise(StandardError.new('some error'))
+        expect { subject.get_type }.to raise_error(Stencil::HTTPClientError)
+      end
+
+      it 'should raise error if http client returns 500' do
+        @stencil_get_stub.to_return(status: 500, body: 'Internal server error', headers: {})
+        expect { subject.get_type }.to raise_error(Stencil::HTTPClientError)
+      end
+
+      it 'should raise error for invalid proto type' do
+        @stencil_get_stub.to_return(status: 200, body: File.new('spec/data/desc-proto-bin'), headers: {})
+
+        proto_name = "incorrect"
+        expect { subject.get_type(proto_name) }.to raise_error(Stencil::InvalidProtoClass)
+      end
+
+      it 'should successfully return proto type' do
+        @stencil_get_stub.to_return(status: 200, body: File.new('spec/data/desc-proto-bin'), headers: {})
+
+        proto_name = "com.gojek.esb.types.ServiceType"
+        actual_type = subject.get_type(proto_name)
+        expect(actual_type).to eq(service_type_message)
+      end
+    end
+  end
+end

clients/ruby/spec/stencil/client_spec.rb

@@ -3,11 +3,11 @@ module Stencil
     let(:configuration) { Stencil.configuration }
 
     it 'should set registry urls correctly' do
-      expect(configuration.registry_urls).to eq([])
+      expect(configuration.registry_url).to eq(nil)
 
-      expected_value = ['http://localhost:3000']
-      configuration.registry_urls = expected_value
-      expect(configuration.registry_urls).to eq(expected_value)
+      expected_value = 'http://localhost:3000'
+      configuration.registry_url = expected_value
+      expect(configuration.registry_url).to eq(expected_value)
     end
 
 
@@ -42,19 +42,17 @@ module Stencil
       expect(configuration.bearer_token).to eq(expected_bearer_token)
     end
 
-
-
     describe '#configure' do
       let(:refresh_enabled) {true}
       let(:refresh_ttl_in_secs) {60000}
-      let(:registry_urls) {["abc.com/latest"]}
+      let(:registry_url) {"abc.com/latest"}
       let(:token) {"ABCD1234"}
       let(:bearer_token) {"Bearer " + token}
       let(:http_timeout) {6000}
 
       before(:each) do
         Stencil.configure do |config|
-          config.registry_urls = registry_urls
+          config.registry_url = registry_url
           config.bearer_token = token
           config.refresh_enabled = refresh_enabled
           config.refresh_ttl_in_secs = refresh_ttl_in_secs
@@ -65,7 +63,7 @@ module Stencil
       subject { Stencil.configuration }
 
       it 'should set configuration correctly' do
-        expect(subject.registry_urls).to eq(registry_urls)
+        expect(subject.registry_url).to eq(registry_url)
         expect(subject.bearer_token).to eq(bearer_token)
         expect(subject.refresh_enabled).to eq(refresh_enabled)
         expect(subject.refresh_ttl_in_secs).to eq(refresh_ttl_in_secs)

clients/ruby/spec/stencil/configuration_spec.rb

@@ -28,4 +28,5 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
 
   spec.add_development_dependency "bundler", "~> 1.17.3"
+  spec.add_development_dependency "webmock", "~> 3.14.0"
 end