feat(custom provider header): Allow a --custom-provider-header to be …

…specified

This header will be added to the replayed requests AND the provider state setup request.
It is intended to allow valid authorization credentials to be used in the situation where
authorization cannot be turned off in the provider when verifying pacts.

lib/pact/provider_verifier/add_header_middlware.rb

@@ -0,0 +1,33 @@
+module Pact
+  module ProviderVerifier
+    class AddHeaderMiddlware
+
+      def initialize app, headers
+        @app = app
+        @headers = headers
+      end
+
+      def call env
+        @app.call(add_headers(env))
+      end
+
+      def add_headers env
+        new_env = env.dup
+        @headers.each_pair do | key, value |
+          header_name = "HTTP_#{key.upcase.gsub("-", "_")}"
+          warn_about_header_replacement key, new_env[header_name], value
+          new_env[header_name] = value
+        end
+        new_env
+      end
+
+      def warn_about_header_replacement header_name, existing_value, new_value
+        if existing_value.nil?
+          $stderr.puts "WARN: Adding header '#{header_name}: #{new_value}' to replayed request. This header did not exist in the pact, and hence this test cannot confirm that the request will work in real life."
+        else
+          $stdout.puts "INFO: Replacing header '#{header_name}: #{existing_value}' with '#{header_name}: #{new_value}'"
+        end
+      end
+    end
+  end
+end

lib/pact/provider_verifier/app.rb

@@ -6,6 +6,7 @@
 require 'net/https'
 require 'faraday_middleware'
 require 'json'
+require 'pact/provider_verifier/add_header_middlware'
 
 module Pact
   module ProviderVerifier
@@ -33,16 +34,23 @@ def verify_pacts
         proxy_pact_helper = File.expand_path(File.join(File.dirname(__FILE__), "pact_helper.rb"))
         ENV['PROVIDER_STATES_SETUP_URL'] = @options.provider_states_setup_url
         ENV['VERBOSE_LOGGING'] = @options.verbose if @options.verbose
+        ENV['CUSTOM_PROVIDER_HEADER'] = @options.custom_provider_header if @options.custom_provider_header
         provider_base_url = @options.provider_base_url
 
         provider_application_version = @options.provider_app_version
         publish_results  = @options.publish_verification_results
 
+        rack_reverse_proxy = Rack::ReverseProxy.new do
+          reverse_proxy '/', provider_base_url
+        end
+
+        if @options.custom_provider_header
+          rack_reverse_proxy = Pact::ProviderVerifier::AddHeaderMiddlware.new(rack_reverse_proxy, parse_header)
+        end
+
         Pact.service_provider "Running Provider Application" do
           app do
-            Rack::ReverseProxy.new do
-              reverse_proxy '/', provider_base_url
-            end
+            rack_reverse_proxy
           end
 
           if provider_application_version
@@ -74,6 +82,11 @@ def verify_pacts
         exit exit_statuses.count{ | status | status != 0 }
       end
 
+      def parse_header
+        header_name, header_value = @options.custom_provider_header.split(":", 2).collect(&:strip)
+        {header_name => header_value}
+      end
+
       def print_deprecation_note
         if @options.provider_states_url
           $stderr.puts "The --provider-states-url option is deprecated and the URL endpoint can be removed from the application"

lib/pact/provider_verifier/cli.rb

@@ -14,6 +14,7 @@ class CLI < Thor
       method_option :broker_username, aliases: "-n", desc: "Pact Broker username", :required => false
       method_option :broker_password, aliases: "-p", desc: "Pact Broker password", :required => false
       method_option :verbose, aliases: "-v", desc: "Verbose output", :required => false
+      method_option :custom_provider_header, desc: "Header to add to provider state set up and pact requests. eg 'Authorization: Basic cGFjdDpwYWN0'", :required => false
       method_option :provider_states_url, aliases: "-s", desc: "DEPRECATED", :required => false
 
       def verify

lib/pact/provider_verifier/set_up_provider_state.rb

@@ -36,6 +36,7 @@ def post_to_provider_state
         connection = Faraday.new(:url => provider_states_setup_url)
         connection.post do |req|
           req.headers["Content-Type"] = "application/json"
+          add_custom_provider_header req
           req.body = {consumer: consumer, state: provider_state, states: [provider_state] }.to_json
         end
       end
@@ -48,6 +49,24 @@ def verbose?
         ENV['VERBOSE_LOGGING']
       end
 
+      def provider_header_set?
+        ENV.fetch('CUSTOM_PROVIDER_HEADER', '') != ''
+      end
+
+      def provider_header_name
+        ENV['CUSTOM_PROVIDER_HEADER'].split(":", 2)[0]
+      end
+
+      def provider_header_value
+        ENV['CUSTOM_PROVIDER_HEADER'].split(":", 2)[1]
+      end
+
+      def add_custom_provider_header request
+        if provider_header_set?
+          request[provider_header_name] = provider_header_value
+        end
+      end
+
       def check_for_error response
         if response.status >= 300
           raise SetUpProviderStateError.new("Error setting up provider state '#{provider_state}' for consumer '#{consumer}' at #{provider_states_setup_url}. response status=#{response.status} response body=#{response.body}")

spec/integration_with_custom_header_spec.rb

@@ -0,0 +1,24 @@
+describe "pact-provider-verifier with basic auth" do
+  before(:all) do
+    @pipe = IO.popen("USE_BASIC_AUTH=true bundle exec rackup -p 4567 spec/support/config.ru")
+    sleep 2
+  end
+
+  context "with --custom-provider-header specified" do
+
+    subject { `bundle exec bin/pact-provider-verifier --custom-provider-header "Authorization: Basic cGFjdDpwYWN0" -a 1.0.100 --provider-base-url http://localhost:4567 --pact-urls ./test/me-they.json --provider_states_setup_url http://localhost:4567/provider-state -v` }
+
+    it "exits with a 0 exit code" do
+      subject
+      expect($?).to eq 0
+    end
+
+    it "the output contains a success message" do
+      expect(subject).to include "2 interactions, 0 failures"
+    end
+  end
+
+  after(:all) do
+    Process.kill 'KILL', @pipe.pid
+  end
+end

spec/lib/pact/provider_verifier/add_header_middlware_spec.rb

@@ -0,0 +1,46 @@
+require 'pact/provider_verifier/add_header_middlware'
+
+module Pact
+  module ProviderVerifier
+    describe AddHeaderMiddlware do
+      describe "call" do
+        let(:target_app) { double(:app, call: nil) }
+        let(:middlware) { AddHeaderMiddlware.new(target_app, headers) }
+        let(:headers) { {'Foo-Bar' => 'foo'} }
+
+        before do
+          allow($stdout).to receive(:puts)
+          allow($stderr).to receive(:puts)
+        end
+
+        it "keeps the existing headers" do
+          expect(target_app).to receive(:call) do | env |
+            expect(env['MOO']).to eq 'bar'
+          end
+          middlware.call('MOO' => 'bar')
+        end
+
+        it "adds the headers to the env" do
+          expect(target_app).to receive(:call) do | env |
+            expect(env['HTTP_FOO_BAR']).to eq 'foo'
+          end
+          middlware.call({'HTTP_FOO_BAR' => 'ick'})
+        end
+
+        context "when the specified header does not already exist" do
+          it "warns the user" do
+            expect($stderr).to receive(:puts).with(/WARN: Adding header 'Foo-Bar: foo'/)
+            middlware.call({})
+          end
+        end
+
+        context "when the specified header already exists" do
+          it "notifies the user" do
+            expect($stdout).to receive(:puts).with(/INFO: Replacing header 'Foo-Bar: wiffle' with 'Foo-Bar: foo'/)
+            middlware.call({'HTTP_FOO_BAR' => 'wiffle' })
+          end
+        end
+      end
+    end
+  end
+end

spec/support/config.ru

@@ -1,3 +1,9 @@
 require_relative 'provider'
 
+if ENV['USE_BASIC_AUTH'] == 'true'
+  use Rack::Auth::Basic, "Restricted Area" do |username, password|
+    username == 'pact' and password == 'pact'
+  end
+end
+
 run Provider