added support for redis connection pools

Gemfile

@@ -28,6 +28,7 @@ gem 'mysql2'
 gem 'pg'
 gem 'cuprite'
 gem 'puma'
+gem 'connection_pool'
 
 group(:guard) do
   gem 'guard'

lib/flipper/adapters/redis_pool.rb

@@ -0,0 +1,32 @@
+require 'flipper/adapters/redis'
+require 'connection_pool'
+
+module Flipper
+  module Adapters
+    class RedisPool < Redis
+      def initialize(pool, key_prefix: nil)
+        @pool = pool
+        @key_prefix = key_prefix
+      end
+
+      superclass.instance_methods(false).each do |method|
+        define_method method do |*args|
+          return super(*args) unless @client.nil?
+
+          @pool.with do |client|
+            @client = client
+            super(*args).tap { @client = nil }
+          end
+        end
+      end
+    end
+  end
+end
+
+
+Flipper.configure do |config|
+  config.adapter do
+    client = ConnectionPool.new(size: 1) { Redis.new(url: ENV["FLIPPER_REDIS_URL"] || ENV["REDIS_URL"]) }
+    Flipper::Adapters::RedisPool.new(client)
+  end
+end

spec/flipper/adapters/redis_pool_spec.rb

@@ -0,0 +1,10 @@
+require 'flipper/adapters/redis_pool'
+
+RSpec.describe Flipper::Adapters::RedisPool do
+  subject do
+    pool = ConnectionPool.new(size: 1, &create_client)
+    described_class.new(pool, key_prefix: key_prefix)
+  end
+
+  it_behaves_like "a redis adapter"
+end

spec/flipper/adapters/redis_spec.rb

@@ -1,55 +1,7 @@
 require 'flipper/adapters/redis'
 
 RSpec.describe Flipper::Adapters::Redis do
-  let(:client) do
-    options = {}
+  subject { described_class.new(client, key_prefix: key_prefix) }
 
-    options[:url] = ENV['REDIS_URL'] if ENV['REDIS_URL']
-
-    Redis.raise_deprecations = true
-    Redis.new(options)
-  end
-
-  subject { described_class.new(client) }
-
-  before do
-    skip_on_error(Redis::CannotConnectError, 'Redis not available') do
-      client.flushdb
-    end
-  end
-
-  it_should_behave_like 'a flipper adapter'
-
-  it 'configures itself on load' do
-    Flipper.configuration = nil
-    Flipper.instance = nil
-
-    silence { load 'flipper/adapters/redis.rb' }
-
-    expect(Flipper.adapter.adapter).to be_a(Flipper::Adapters::Redis)
-  end
-
-  describe 'with a key_prefix' do
-    let(:subject) { described_class.new(client, key_prefix: "lockbox:") }
-    let(:feature) { Flipper::Feature.new(:search, subject) }
-
-    it_should_behave_like 'a flipper adapter'
-
-    it 'namespaces feature-keys' do
-      subject.add(feature)
-
-      expect(client.smembers("flipper_features")).to eq([])
-      expect(client.exists?("search")).to eq(false)
-      expect(client.smembers("lockbox:flipper_features")).to eq(["search"])
-      expect(client.hgetall("lockbox:search")).not_to eq(nil)
-    end
-
-    it "can remove namespaced keys" do
-      subject.add(feature)
-      expect(client.smembers("lockbox:flipper_features")).to eq(["search"])
-
-      subject.remove(feature)
-      expect(client.smembers("lockbox:flipper_features")).to be_empty
-    end
-  end
+  it_behaves_like "a redis adapter"
 end

spec/support/examples/redis_adapter.rb

@@ -0,0 +1,55 @@
+RSpec.shared_examples "a redis adapter" do
+  let(:create_client) do
+    Proc.new do
+      options = {}
+
+      options[:url] = ENV['REDIS_URL'] if ENV['REDIS_URL']
+
+      Redis.raise_deprecations = true
+      Redis.new(options)
+    end
+  end
+  let(:client) { create_client.call }
+  let(:key_prefix) { nil }
+
+  before do
+    skip_on_error(Redis::CannotConnectError, 'Redis not available') do
+      client.flushdb
+    end
+  end
+
+  it_should_behave_like 'a flipper adapter'
+
+  it 'configures itself on load' do
+    Flipper.configuration = nil
+    Flipper.instance = nil
+
+    silence { load 'flipper/adapters/redis_pool.rb' }
+
+    expect(Flipper.adapter.adapter).to be_a(described_class)
+  end
+
+  describe 'with a key_prefix' do
+    let(:feature) { Flipper::Feature.new(:search, subject) }
+    let(:key_prefix) { "lockbox:" }
+
+    it_should_behave_like 'a flipper adapter'
+
+    it 'namespaces feature-keys' do
+      subject.add(feature)
+
+      expect(client.smembers("flipper_features")).to eq([])
+      expect(client.exists?("search")).to eq(false)
+      expect(client.smembers("lockbox:flipper_features")).to eq(["search"])
+      expect(client.hgetall("lockbox:search")).not_to eq(nil)
+    end
+
+    it "can remove namespaced keys" do
+      subject.add(feature)
+      expect(client.smembers("lockbox:flipper_features")).to eq(["search"])
+
+      subject.remove(feature)
+      expect(client.smembers("lockbox:flipper_features")).to be_empty
+    end
+  end
+end

test/adapters/redis_pool_test.rb

@@ -0,0 +1,15 @@
+require 'test_helper'
+require 'flipper/adapters/redis_pool'
+
+class RedisPoolTest < MiniTest::Test
+  prepend Flipper::Test::SharedAdapterTests
+
+  def setup
+    url = ENV.fetch('REDIS_URL', 'redis://localhost:6379')
+    pool = ConnectionPool.new(size: 1) { Redis.new(url: url) }
+    pool.with { |client| client.flushdb }
+    @adapter = Flipper::Adapters::RedisPool.new(pool)
+  rescue Redis::CannotConnectError
+    ENV['CI'] ? raise : skip('Redis not available')
+  end
+end