test: improved db backwards compatiblity tests

Discovered that 2.0.0 -> 2.1.0 db/code is not backwards compatible,
and updated the documentation to reflect that

Author: bethesque

UPGRADING.md

@@ -1,11 +1,18 @@
 # Upgrading from a previous version of the Pact Broker
 
-## Pact Broker versions >= 2.0.0
+## Pact Broker versions >= 2.1.0
 
-Backwards compatibility for database migrations in relation to the codebase will be supported according to semantic versioning (ie. any backwards incompatible changes will be done in major releases). This means that zero downtime deployments using rolling upgrades for setups with multiple HTTP servers sharing the same database are supported between any 2 versions within the same major release.
+Backwards compatibility tests will ensure that the latest version of the database will be compatible with a previous version of the code until v3.0.0 for the following endpoints:
 
-A migration path will be provided for major releases to allow zero downtime deployments, and will be documented here.
+* Tag version
+* Publish pact
+* Retrieve latest pact
+* Retrieve latest pact for tag
 
-## Pact Broker < 2.0.0
+This means that zero downtime rolling upgrades for architectures that use multiple web servers (eg. Amazon autoscaling groups) are supported between any two versions from 2.1.0.
 
-The upgrade between 1.18.0 and 2.0.0 contains database migrations that are NOT backwards compatible. It is recommended to run a single instance of the broker while performing an upgrade that traverses these versions.
+When backwards-incompatible changes need to be made in the future, a zero downtime upgrade path will documented on this page.
+
+## Pact Broker < 2.1.0
+
+The upgrades between 1.18.0 and 2.1.0 contains database migrations that are NOT backwards compatible with previous versions of the code. It is recommended to run a single instance of the broker while performing an upgrade that traverses these versions.

db/test/backwards_compatibility/Rakefile

@@ -6,9 +6,9 @@ TESTS = [
   %w{2.4.2 9296},
   %w{2.3.0 9295},
   %w{2.2.0 9294},
-  %w{2.1.0 9293},
-  %w{2.0.0 9292}
+  %w{2.1.0 9293}
 ]
+
 DATABASE_VERSION = TESTS.first.first
 
 def start_pact_broker code_version, port
@@ -28,6 +28,7 @@ def clean
   FileUtils.rm_rf 'pids'
   FileUtils.mkdir 'pids'
   FileUtils.rm_rf 'pact_broker_database.sqlite3'
+  FileUtils.rm_rf 'log'
 end
 
 RSpec::Core::RakeTask.new(:spec) do |task|

db/test/backwards_compatibility/config.ru

@@ -13,4 +13,6 @@ app = PactBroker::App.new do | config |
   config.auto_migrate_db = true
 end
 
+PactBroker.logger.info "Running PactBroker #{PactBroker::VERSION}"
+
 run app

db/test/backwards_compatibility/spec/publish_pact_spec.rb

@@ -1,46 +1,69 @@
 require 'rack/reverse_proxy'
+require 'securerandom'
 
-code_version = ENV.fetch('PACT_BROKER_CODE_VERSION')
-database_version = ENV.fetch('PACT_BROKER_DATABASE_VERSION')
-
-describe "Code version #{code_version} running against database version #{database_version}" do
-  describe "Publishing a pact" do
-
-    before do
-      unless ENV['OK']
-        retries = 0
-        begin
-            get "/"
-            ENV['OK'] = 'true'
-        rescue Errno::ECONNREFUSED => error
-          if retries < 10
-            retries += 1
-            sleep 1
-            retry
-          else
-            raise error
-          end
-        end
-      end
+CODE_VERSION = ENV.fetch('PACT_BROKER_CODE_VERSION')
+DATABASE_VERSION = ENV.fetch('PACT_BROKER_DATABASE_VERSION')
+CONSUMER_VERSION = CODE_VERSION == 'head' ? '100.100.100' : CODE_VERSION
+TAG = SecureRandom.hex
+
+describe "Code version #{CODE_VERSION} running against database version #{DATABASE_VERSION}" do
+
+  before do
+    wait_for_server_to_start
+  end
+
+  let(:path) { "/pacts/provider/Bar/consumer/Foo/version/#{CONSUMER_VERSION}" }
+  let(:response_body_json) { JSON.parse(subject.body) }
+  let(:pact_content) do
+    pact = load_json_fixture('foo-bar.json')
+    pact['interactions'][0]['providerState'] = "the code version is #{CODE_VERSION}"
+    pact.to_json
+  end
+
+  let(:app) do
+    Rack::ReverseProxy.new do
+      reverse_proxy_options preserve_host: true
+      reverse_proxy '/', "http://localhost:#{ENV.fetch('PORT')}/"
     end
+  end
 
-    let(:pact_content) { load_fixture('foo-bar.json') }
-    let(:path) { "/pacts/provider/Bar/consumer/Foo/version/1.2.3" }
-    let(:response_body_json) { JSON.parse(subject.body) }
+  describe "tagging a consumer version" do
+    let(:path) { "/pacticipants/Foo/versions/#{CONSUMER_VERSION}/tags/#{TAG}"}
+    subject { put path, nil, {'CONTENT_TYPE' => 'application/json' }; last_response  }
 
-    let(:app) do
-      Rack::ReverseProxy.new do
-        reverse_proxy_options preserve_host: true
-        reverse_proxy '/', "http://localhost:#{ENV.fetch('PORT')}/"
-      end
+    it "returns a success status" do
+      expect(subject.status.to_s).to match /20\d/
     end
+  end
 
+  describe "publishing a pact" do
     subject { put path, pact_content, {'CONTENT_TYPE' => 'application/json' }; last_response  }
 
-
     it "returns a success status" do
       expect(subject.status.to_s).to match /20\d/
     end
+  end
+
+  describe "retrieving a pact" do
+    subject { get path; last_response  }
+
+    it "returns the pact in the body" do
+      expect(response_body_json).to include JSON.parse(pact_content)
+    end
+  end
+
+  describe "retrieving the latest tagged pact" do
+    let(:path) { "/pacts/provider/Bar/consumer/Foo/latest" }
+    subject { get path; last_response  }
+
+    it "returns the latest pact" do
+      expect(subject.headers['X-Pact-Consumer-Version']).to eq '100.100.100'
+    end
+  end
+
+  describe "retrieving the latest tagged pact" do
+    let(:path) { "/pacts/provider/Bar/consumer/Foo/latest/#{TAG}" }
+    subject { get path; last_response  }
 
     it "returns the pact in the body" do
       expect(response_body_json).to include JSON.parse(pact_content)

db/test/backwards_compatibility/spec/spec_helper.rb

@@ -1,13 +1,20 @@
 require 'support/fixture_helpers'
+require 'support/request_helpers'
 require 'rack/test'
 
 RSpec.configure do | config |
 
   config.include Rack::Test::Methods
+  config.include RequestHelpers
+  config.include FixtureHelpers
 
   config.mock_with :rspec do |mocks|
     mocks.verify_partial_doubles = true
   end
 
-  config.include FixtureHelpers
+  config.after(:suite) do
+    puts "***************************************************************************"
+    puts "Pact Broker logs are in db/test/backwards_compatibility/log/pact_broker.log"
+    puts "***************************************************************************"
+  end
 end

db/test/backwards_compatibility/spec/support/request_helpers.rb

@@ -0,0 +1,20 @@
+module RequestHelpers
+
+  def wait_for_server_to_start
+    unless ENV['OK']
+      retries = 0
+      begin
+          get "/"
+          ENV['OK'] = 'true'
+      rescue Errno::ECONNREFUSED => error
+        if retries < 10
+          retries += 1
+          sleep 1
+          retry
+        else
+          raise error
+        end
+      end
+    end
+  end
+end

tasks/db.rake

@@ -8,6 +8,16 @@ namespace :bundler do
 end
 
 namespace :db do
+
+  task :spec do
+    Bundler.with_clean_env do
+      # todo check for ruby version
+      system('cd db/test/backwards_compatibility && bundle exec rake db:check_backwards_compatibility')
+      success = $?.exitstatus == 0
+      exit(1) unless success
+    end
+  end
+
   task :env => ['bundler:setup'] do
     # Require RACK_ENV to be set for tasks that will be called in production
     raise "Please specify RACK_ENV" unless ENV['RACK_ENV']