chore: refactor redis config (#1310)

- refactor Redis config in Redis::Config Module
-  unit tests for Redis::Config module

config/initializers/redis.rb

@@ -1,24 +1,5 @@
-app_redis_config = {
-  url: URI.parse(ENV.fetch('REDIS_URL', 'redis://127.0.0.1:6379')),
-  password: ENV.fetch('REDIS_PASSWORD', nil).presence
-}
+redis = Rails.env.test? ? MockRedis.new : Redis.new(Redis::Config.app)
 
-if ENV['REDIS_SENTINELS'].presence
-  default_sentinel_port = '26379'
-  # expected format for REDIS_SENTINELS url string is host1:port1, host2:port2
-  sentinels = ENV['REDIS_SENTINELS'].split(',').map do |sentinel_url|
-    host, port = sentinel_url.split(':').map(&:strip)
-    { host: host, port: port || default_sentinel_port, password: app_redis_config[:password] }
-  end
-
-  master_name = ENV.fetch('REDIS_SENTINEL_MASTER_NAME', 'mymaster')
-  # over-write redis url as redis://:<your-redis-password>@<master-name>/ when using sentinel
-  # more at https://github.com/redis/redis-rb/issues/531#issuecomment-263501322
-  app_redis_config[:url] = URI.parse("redis://#{master_name}")
-  app_redis_config[:sentinels] = sentinels
-end
-
-redis = Rails.env.test? ? MockRedis.new : Redis.new(app_redis_config)
 # Alfred
 # Add here as you use it for more features
 # Used for Round Robin, Conversation Emails & Online Presence

config/initializers/sidekiq.rb

@@ -1,12 +1,7 @@
-sidekiq_redis_config = {
-  url: ENV.fetch('REDIS_URL', 'redis://127.0.0.1:6379'),
-  password: ENV.fetch('REDIS_PASSWORD', nil).presence
-}
-
 Sidekiq.configure_client do |config|
-  config.redis = sidekiq_redis_config.merge(size: 25)
+  config.redis = Redis::Config.sidekiq
 end
 
 Sidekiq.configure_server do |config|
-  config.redis = sidekiq_redis_config.merge(size: 25)
+  config.redis = Redis::Config.sidekiq
 end

lib/redis/config.rb

@@ -0,0 +1,48 @@
+module Redis::Config
+  DEFAULT_SENTINEL_PORT = '26379'.freeze
+  SIDEKIQ_SIZE = 25
+
+  class << self
+    def app
+      return BASE_CONFIG if const_defined? 'BASE_CONFIG'
+
+      reload_config
+    end
+
+    def sidekiq
+      config = begin
+        if const_defined? 'BASE_CONFIG'
+          BASE_CONFIG
+        else
+          reload_config
+        end
+      end
+      config.merge(size: SIDEKIQ_SIZE)
+    end
+
+    def reload_config
+      config = {
+        url: ENV.fetch('REDIS_URL', 'redis://127.0.0.1:6379'),
+        password: ENV.fetch('REDIS_PASSWORD', nil).presence
+      }
+
+      sentinel_string = ENV.fetch('REDIS_SENTINELS', nil)
+      if sentinel_string.presence
+        # expected format for REDIS_SENTINELS url string is host1:port1, host2:port2
+        sentinels = sentinel_string.split(',').map do |sentinel_url|
+          host, port = sentinel_url.split(':').map(&:strip)
+          { host: host, port: port || DEFAULT_SENTINEL_PORT, password: config[:password] }
+        end
+
+        master_name = ENV.fetch('REDIS_SENTINEL_MASTER_NAME', 'mymaster')
+        # over-write redis url as redis://:<your-redis-password>@<master-name>/ when using sentinel
+        # more at https://github.com/redis/redis-rb/issues/531#issuecomment-263501322
+        config[:url] = "redis://#{master_name}"
+        config[:sentinels] = sentinels
+      end
+      send(:remove_const, 'BASE_CONFIG') if const_defined? 'BASE_CONFIG'
+      const_set('BASE_CONFIG', config)
+      BASE_CONFIG
+    end
+  end
+end

spec/lib/redis/config_spec.rb

@@ -0,0 +1,65 @@
+require 'rails_helper'
+
+describe ::Redis::Config do
+  context 'when single redis instance is used' do
+    let(:redis_url) { 'redis://my-redis-instance:6379' }
+    let(:redis_pasword) { 'some-strong-password' }
+
+    before do
+      allow(ENV).to receive(:fetch).with('REDIS_URL', 'redis://127.0.0.1:6379').and_return(redis_url)
+      allow(ENV).to receive(:fetch).with('REDIS_PASSWORD', nil).and_return(redis_pasword)
+      allow(ENV).to receive(:fetch).with('REDIS_SENTINELS', nil).and_return('')
+      allow(ENV).to receive(:fetch).with('REDIS_SENTINEL_MASTER_NAME', 'mymaster').and_return('')
+      described_class.reload_config
+    end
+
+    it 'checks for app redis config' do
+      app_config = described_class.app
+      expect(app_config.keys).to match_array([:url, :password])
+      expect(app_config[:url]).to eq(redis_url)
+      expect(app_config[:password]).to eq(redis_pasword)
+    end
+
+    it 'checks for sidekiq redis config' do
+      sidekiq_config = described_class.sidekiq
+      expect(sidekiq_config.keys).to match_array([:url, :password, :size])
+      expect(sidekiq_config[:url]).to eq redis_url
+      expect(sidekiq_config[:password]).to eq redis_pasword
+      expect(sidekiq_config[:size]).to eq described_class::SIDEKIQ_SIZE
+    end
+  end
+
+  context 'when redis sentinel is used' do
+    let(:redis_url) { 'redis://my-redis-instance:6379' }
+    let(:redis_sentinels) { 'sentinel_1:1234, sentinel_2:4321, sentinel_3' }
+    let(:redis_master_name) { 'master-name' }
+    let(:redis_pasword) { 'some-strong-password' }
+
+    let(:expected_sentinels) do
+      [
+        { host: 'sentinel_1', port: '1234', password: 'some-strong-password' },
+        { host: 'sentinel_2', port: '4321', password: 'some-strong-password' },
+        { host: 'sentinel_3', port: '26379', password: 'some-strong-password' }
+      ]
+    end
+
+    before do
+      allow(ENV).to receive(:fetch).with('REDIS_URL', 'redis://127.0.0.1:6379').and_return(redis_url)
+      allow(ENV).to receive(:fetch).with('REDIS_PASSWORD', nil).and_return(redis_pasword)
+      allow(ENV).to receive(:fetch).with('REDIS_SENTINELS', nil).and_return(redis_sentinels)
+      allow(ENV).to receive(:fetch).with('REDIS_SENTINEL_MASTER_NAME', 'mymaster').and_return(redis_master_name)
+      described_class.reload_config
+    end
+
+    it 'checks for app redis config' do
+      expect(described_class.app.keys).to match_array([:url, :password, :sentinels])
+      expect(described_class.app[:url]).to eq("redis://#{redis_master_name}")
+      expect(described_class.app[:sentinels]).to match_array(expected_sentinels)
+    end
+
+    it 'checks for sidekiq redis config' do
+      expect(described_class.sidekiq.keys).to match_array([:url, :password, :sentinels, :size])
+      expect(described_class.sidekiq[:size]).to eq described_class::SIDEKIQ_SIZE
+    end
+  end
+end