add Fetcher for http requests

Gemfile

@@ -42,6 +42,7 @@ group :test do
   gem "fixture_builder",           "~> 0.4.1"
   gem "factory_girl_rails",        "~> 4.5.0"
   gem "rspec-collection_matchers", "~> 1.1.2"
+  gem "webmock",                   "~> 1.21.0"
 end
 
 group :development, :test do

Gemfile.lock

@@ -2,7 +2,10 @@ PATH
   remote: .
   specs:
     diaspora_federation (0.0.3)
+      faraday (~> 0.9.0)
+      faraday_middleware (~> 0.9.0)
       nokogiri (~> 1.6, >= 1.6.6)
+      typhoeus (~> 0.7.0)
     diaspora_federation-rails (0.0.3)
       diaspora_federation (= 0.0.3)
       rails (~> 4.2)
@@ -45,6 +48,7 @@ GEM
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
+    addressable (2.3.8)
     arel (6.0.0)
     ast (2.0.0)
     astrolabe (1.3.0)
@@ -56,14 +60,22 @@ GEM
       simplecov (>= 0.7.1, < 1.0.0)
     coderay (1.1.0)
     columnize (0.9.0)
+    crack (0.4.2)
+      safe_yaml (~> 1.0.0)
     diff-lcs (1.2.5)
     docile (1.1.5)
     erubis (2.7.0)
+    ethon (0.7.4)
+      ffi (>= 1.3.0)
     factory_girl (4.5.0)
       activesupport (>= 3.0.0)
     factory_girl_rails (4.5.0)
       factory_girl (~> 4.5.0)
       railties (>= 3.0.0)
+    faraday (0.9.1)
+      multipart-post (>= 1.2, < 3)
+    faraday_middleware (0.9.2)
+      faraday (>= 0.7.4, < 0.10)
     ffi (1.9.10)
     fixture_builder (0.4.1)
       activerecord (>= 2)
@@ -111,6 +123,7 @@ GEM
     mini_portile (0.6.2)
     minitest (5.7.0)
     multi_json (1.11.1)
+    multipart-post (2.0.0)
     nenv (0.2.0)
     nokogiri (1.6.6.2)
       mini_portile (~> 0.6.0)
@@ -193,6 +206,7 @@ GEM
       rainbow (>= 1.99.1, < 3.0)
       ruby-progressbar (~> 1.4)
     ruby-progressbar (1.7.5)
+    safe_yaml (1.0.4)
     shellany (0.0.1)
     simplecov (0.10.0)
       docile (~> 1.1.0)
@@ -218,10 +232,15 @@ GEM
     systemu (2.6.5)
     thor (0.19.1)
     thread_safe (0.3.5)
+    typhoeus (0.7.2)
+      ethon (>= 0.7.4)
     tzinfo (1.2.2)
       thread_safe (~> 0.1)
     uuid (2.3.8)
       macaddr (~> 1.0)
+    webmock (1.21.0)
+      addressable (>= 2.3.6)
+      crack (>= 0.3.2)
     yard (0.8.7.6)
 
 PLATFORMS
@@ -250,6 +269,7 @@ DEPENDENCIES
   spring-watcher-listen
   sqlite3 (~> 1.3.10)
   uuid (~> 2.3.8)
+  webmock (~> 1.21.0)
   yard
 
 BUNDLED WITH

diaspora_federation.gemspec

@@ -21,4 +21,7 @@ Gem::Specification.new do |s|
   s.required_ruby_version = "~> 2.0"
 
   s.add_dependency "nokogiri", "~> 1.6", ">= 1.6.6"
+  s.add_dependency "faraday", "~> 0.9.0"
+  s.add_dependency "faraday_middleware", "~> 0.9.0"
+  s.add_dependency "typhoeus", "~> 0.7.0"
 end

lib/diaspora_federation.rb

@@ -4,6 +4,8 @@ require "diaspora_federation/callbacks"
 require "diaspora_federation/properties_dsl"
 require "diaspora_federation/entity"
 
+require "diaspora_federation/fetcher"
+
 require "diaspora_federation/discovery"
 
 # diaspora* federation library
@@ -30,6 +32,12 @@ module DiasporaFederation
     #   config.server_uri = AppConfig.pod_uri
     attr_accessor :server_uri
 
+    # Set the bundle of certificate authorities (CA) certificates
+    #
+    # @example
+    #   config.certificate_authorities = AppConfig.environment.certificate_authorities.get
+    attr_accessor :certificate_authorities
+
     # configure the federation library
     #
     # @example
@@ -63,10 +71,17 @@ module DiasporaFederation
     # called from after_initialize
     # @raise [ConfigurationError] if the configuration is incomplete or invalid
     def validate_config
-      configuration_error "Missing server_uri" unless @server_uri.respond_to? :host
+      configuration_error "server_uri: Missing or invalid" unless @server_uri.respond_to? :host
+
+      configuration_error "certificate_authorities: Not configured" if @certificate_authorities.nil?
+      unless File.file? @certificate_authorities
+        configuration_error "certificate_authorities: File not found: #{@certificate_authorities}"
+      end
+
       unless @callbacks.definition_complete?
         configuration_error "Missing handlers for #{@callbacks.missing_handlers.join(', ')}"
       end
+
       logger.info "successfully configured the federation library"
     end
 

lib/diaspora_federation/fetcher.rb

@@ -0,0 +1,42 @@
+require "faraday"
+require "faraday_middleware/response/follow_redirects"
+require "typhoeus/adapters/faraday"
+
+module DiasporaFederation
+  # A wrapper for {https://github.com/lostisland/faraday Faraday} used for
+  # fetching
+  #
+  # @see Discovery::Discovery
+  class Fetcher
+    # Perform a GET request
+    #
+    # @param [String] uri the URI
+    # @return [Faraday::Response] the response
+    def self.get(uri)
+      connection.get(uri)
+    end
+
+    # gets the Faraday connection
+    #
+    # @return [Faraday::Connection] the response
+    def self.connection
+      create_default_connection unless @connection
+      @connection.dup
+    end
+
+    def self.create_default_connection
+      options = {
+        request: {timeout: 30},
+        ssl:     {ca_file: DiasporaFederation.certificate_authorities}
+      }
+
+      @connection = Faraday::Connection.new(options) do |builder|
+        builder.use FaradayMiddleware::FollowRedirects, limit: 4
+        builder.adapter :typhoeus
+      end
+
+      @connection.headers["User-Agent"] = "DiasporaFederation/#{DiasporaFederation::VERSION}"
+    end
+    private_class_method :create_default_connection
+  end
+end

spec/lib/diaspora_federation/fetcher_spec.rb

@@ -0,0 +1,56 @@
+module DiasporaFederation
+  describe Fetcher do
+    describe ".get" do
+      it "gets the url" do
+        stub_request(:get, "http://www.example.com")
+          .to_return(body: "foobar", status: 200)
+
+        response = Fetcher.get("http://www.example.com")
+        expect(response.body).to eq("foobar")
+      end
+
+      it "follows redirects" do
+        stub_request(:get, "http://www.example.com")
+          .to_return(status: 302, headers: {"Location" => "http://www.example.com/redirected"})
+        stub_request(:get, "http://www.example.com/redirected")
+          .to_return(body: "foobar", status: 200)
+
+        response = Fetcher.get("http://www.example.com")
+        expect(response.body).to eq("foobar")
+      end
+
+      it "follows redirects 4 times" do
+        stub_request(:get, "http://www.example.com")
+          .to_return(status: 302, headers: {"Location" => "http://www.example.com"}).times(4)
+          .to_return(status: 200)
+
+        Fetcher.get("http://www.example.com")
+      end
+
+      it "follows redirects not more than 4 times" do
+        stub_request(:get, "http://www.example.com")
+          .to_return(status: 302, headers: {"Location" => "http://www.example.com"})
+
+        expect { Fetcher.get("http://www.example.com") }.to raise_error FaradayMiddleware::RedirectLimitReached
+      end
+
+      it "uses the gem name as User-Agent" do
+        stub_request(:get, "http://www.example.com")
+          .with(headers: {"User-Agent" => "DiasporaFederation/#{DiasporaFederation::VERSION}"})
+
+        Fetcher.get("http://www.example.com")
+      end
+    end
+
+    describe ".connection" do
+      it "returns a new connection every time" do
+        expect(Fetcher.connection).to be_a Faraday::Connection
+      end
+
+      it "returns a new connection every time" do
+        connection1 = Fetcher.connection
+        expect(Fetcher.connection).to_not be(connection1)
+      end
+    end
+  end
+end

spec/lib/diaspora_federation_spec.rb

@@ -6,14 +6,31 @@ module DiasporaFederation
         DiasporaFederation.validate_config
       end
 
-      it "should fails if the server_uri is missing" do
+      it "should fail if the server_uri is missing" do
         temp = DiasporaFederation.server_uri
         DiasporaFederation.server_uri = nil
-        expect { DiasporaFederation.validate_config }.to raise_error ConfigurationError, "Missing server_uri"
+        expect { DiasporaFederation.validate_config }.to raise_error ConfigurationError,
+                                                                     "server_uri: Missing or invalid"
         DiasporaFederation.server_uri = temp
       end
 
-      it "should validate the config" do
+      it "should fail if the certificate_authorities is missing" do
+        temp = DiasporaFederation.certificate_authorities
+        DiasporaFederation.certificate_authorities = nil
+        expect { DiasporaFederation.validate_config }.to raise_error ConfigurationError,
+                                                                     "certificate_authorities: Not configured"
+        DiasporaFederation.certificate_authorities = temp
+      end
+
+      it "should fail if the certificate_authorities is missing" do
+        temp = DiasporaFederation.certificate_authorities
+        DiasporaFederation.certificate_authorities = "/unknown"
+        expect { DiasporaFederation.validate_config }.to raise_error ConfigurationError,
+                                                                     "certificate_authorities: File not found: /unknown"
+        DiasporaFederation.certificate_authorities = temp
+      end
+
+      it "should validate the callbacks" do
         expect(DiasporaFederation.callbacks).to receive(:definition_complete?).and_return(false)
         expect { DiasporaFederation.validate_config }.to raise_error ConfigurationError, "Missing handlers for "
       end

spec/spec_helper.rb

@@ -18,6 +18,7 @@ ENV["RAILS_ENV"] ||= "test"
 require File.join(File.dirname(__FILE__), "..", "test", "dummy", "config", "environment")
 
 require "rspec/rails"
+require "webmock/rspec"
 
 # load factory girl factories
 require "factories"

test/dummy/config/initializers/diaspora_federation.rb

@@ -1,10 +1,20 @@
 require "diaspora_federation/discovery"
 
+if File.file?("/etc/ssl/certs/ca-certificates.crt")
+  # For Debian, Ubuntu, Archlinux, Gentoo
+  ca_file = "/etc/ssl/certs/ca-certificates.crt"
+else
+  # For CentOS, Fedora
+  ca_file = "/etc/pki/tls/certs/ca-bundle.crt"
+end
+
 # configure the federation engine
 DiasporaFederation.configure do |config|
   # the pod url
   config.server_uri = URI("http://localhost:3000/")
 
+  config.certificate_authorities = ca_file
+
   config.define_callbacks do
     on :person_webfinger_fetch do |handle|
       person = Person.find_by(diaspora_handle: handle)