Add RedisConfigurationProvider

This abstracts away where we're getting our redis URL from so that we
can support either the existing behavior, or an override of `REDIS_URL`
in the environment.

api/Gemfile

@@ -37,6 +37,7 @@ gem 'rails', '5.2.1'
 gem 'activeadmin'
 gem 'addressable'
 gem 'bcrypt'
+gem 'cf-app-utils'
 gem 'devise'
 gem 'friendly_id', '5.1.0'
 gem 'inherited_resources'
@@ -56,6 +57,7 @@ group :development, :test do
   gem 'shoulda-matchers'
   gem 'webmock'
   gem 'tzinfo-data'
+  gem 'climate_control'
   gem 'action-cable-testing'
 end
 
@@ -67,7 +69,6 @@ group :development do
 end
 
 group :production do
-  gem 'cf-app-utils'
   gem 'redis', '~> 3.3.3'
   gem 'mysql2'
   gem 'pg'

api/Gemfile.lock

@@ -70,6 +70,7 @@ GEM
       uniform_notifier (~> 1.11.0)
     byebug (10.0.2)
     cf-app-utils (0.6)
+    climate_control (0.2.0)
     coderay (1.1.2)
     coffee-rails (4.2.2)
       coffee-script (>= 2.2.0)
@@ -314,6 +315,7 @@ DEPENDENCIES
   bcrypt
   bullet
   cf-app-utils
+  climate_control
   devise
   dotenv-rails
   friendly_id (= 5.1.0)

api/config/application.rb

@@ -51,7 +51,7 @@ class Application < Rails::Application
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration should go into files in config/initializers
     # -- all .rb files in that directory are automatically loaded.
-
+    config.autoload_paths << Rails.root.join('lib', 'configurations')
     config.session_time = (ENV['SESSION_TIME'] || 120).to_i.minutes
   end
 end

api/config/cable.yml

@@ -36,4 +36,4 @@ test:
 
 production:
   adapter: redis
-  url: <%= ENV["RAILS_ENV"] == "production" && (c = CF::App::Credentials.find_by_service_tag('redis')) && Addressable::URI.new(scheme: 'redis', host: c["hostname"] || c.fetch('host'), password: c['password'], port: c.fetch('port')).to_s %>
+  url: <%= RedisConfigurationProvider.new.redis_config %>

api/lib/configurations/redis_configuration_provider.rb

@@ -0,0 +1,44 @@
+#
+# Postfacto, a free, open-source and self-hosted retro tool aimed at helping
+# remote teams.
+#
+# Copyright (C) 2016 - Present Pivotal Software, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+#
+# it under the terms of the GNU Affero General Public License as
+#
+# published by the Free Software Foundation, either version 3 of the
+#
+# License, or (at your option) any later version.
+#
+#
+#
+# This program is distributed in the hope that it will be useful,
+#
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+#
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#
+# GNU Affero General Public License for more details.
+#
+#
+#
+# You should have received a copy of the GNU Affero General Public License
+#
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+#
+require 'cf-app-utils'
+
+class RedisConfigurationProvider
+  def redis_config
+    return nil unless ENV['RAILS_ENV'] == 'production'
+    return ENV['REDIS_URL'] unless ENV['REDIS_URL'].nil?
+
+    unless ENV['VCAP_SERVICES'].nil?
+      c = CF::App::Credentials.find_by_service_tag('redis')
+      host = c['hostname'] || c.fetch('host')
+      Addressable::URI.new(scheme: 'redis', host: host, password: c['password'], port: c.fetch('port')).to_s
+    end
+  end
+end

api/spec/lib/redis_configuration_provider_spec.rb

@@ -0,0 +1,146 @@
+#
+# Postfacto, a free, open-source and self-hosted retro tool aimed at helping
+# remote teams.
+#
+# Copyright (C) 2016 - Present Pivotal Software, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+#
+# it under the terms of the GNU Affero General Public License as
+#
+# published by the Free Software Foundation, either version 3 of the
+#
+# License, or (at your option) any later version.
+#
+#
+#
+# This program is distributed in the hope that it will be useful,
+#
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+#
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#
+# GNU Affero General Public License for more details.
+#
+#
+#
+# You should have received a copy of the GNU Affero General Public License
+#
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+#
+require 'redis_configuration_provider'
+require 'climate_control'
+
+describe RedisConfigurationProvider do
+  let(:subject) { RedisConfigurationProvider.new }
+
+  describe '#redis_config' do
+    around do |example|
+      ClimateControl.modify('RAILS_ENV' => rails_env, 'VCAP_SERVICES' => vcap_services, 'REDIS_URL' => redis_url) do
+        example.run
+      end
+    end
+
+    context 'when running outside of production' do
+      let(:rails_env) { 'development' }
+      let(:vcap_services) { 'unused-vcap-services-value' }
+      let(:redis_url) { 'unused-redis-url=-value' }
+
+      it 'is nil ' do
+        expect(subject.redis_config).to be_nil
+      end
+    end
+
+    context 'when running in production' do
+      let(:rails_env) { 'production' }
+
+      context 'when REDIS_URL is defined in the environment' do
+        let(:redis_url) { 'redis://user:pass@hostname.com:420' }
+
+        context 'when VCAP_SERVICES is defined in the environment' do
+          let(:vcap_services) do
+            {
+              'redis' => [
+                {
+                  'tags' => 'redis',
+                  'credentials' => {
+                    'hostname' => 'hostname',
+                    'password' => 'pass',
+                    'port' => 234
+                  }
+                }
+              ]
+            }.to_json
+          end
+
+          it 'returns the url from REDIS_URL' do
+            expect(subject.redis_config).to eq('redis://user:pass@hostname.com:420')
+          end
+        end
+
+        context 'when VCAP_SERVICES is NOT defined in the environment' do
+          let(:vcap_services) { nil }
+          it 'returns the url from REDIS_URL' do
+            expect(subject.redis_config).to eq('redis://user:pass@hostname.com:420')
+          end
+        end
+      end
+
+      context 'when REDIS_URL is not defined in the environment' do
+        let(:redis_url) { nil }
+
+        context 'when VCAP_SERVICES is defined in the environment' do
+          context 'and host is declared as host' do
+            let(:vcap_services) do
+              {
+                'redis' => [
+                  {
+                    'tags' => 'redis',
+                    'credentials' => {
+                      'hostname' => 'hostname',
+                      'password' => 'pass',
+                      'port' => 234
+                    }
+                  }
+                ]
+              }.to_json
+            end
+
+            it 'builds a URL based upon the redis service described by vcap services' do
+              expect(subject.redis_config).to eq('redis://:pass@hostname:234')
+            end
+          end
+
+          context 'and host is declared as hostname' do
+            let(:vcap_services) do
+              {
+                'redis' => [
+                  {
+                    'tags' => 'redis',
+                    'credentials' => {
+                      'host' => 'host',
+                      'password' => 'pass',
+                      'port' => 234
+                    }
+                  }
+                ]
+              }.to_json
+            end
+
+            it 'builds a URL based upon the redis service described by vcap services' do
+              expect(subject.redis_config).to eq('redis://:pass@host:234')
+            end
+          end
+        end
+
+        context 'when VCAP_SERVICES is NOT defined in the environment' do
+          let(:vcap_services) { nil }
+
+          it 'returns nil' do
+            expect(subject.redis_config).to be_nil
+          end
+        end
+      end
+    end
+  end
+end