Support multiple Redis instances based on queue type

1 files changed, 210 insertions, 0 deletions

diff --git a/spec/support/redis/redis_shared_examples.rb b/spec/support/redis/redis_shared_examples.rb
new file mode 100644
index 00000000000..95a5df181c1
--- /dev/null
+++ b/spec/support/redis/redis_shared_examples.rb
@@ -0,0 +1,210 @@
+RSpec.shared_examples "redis_shared_examples" do
+  include StubENV
+
+  let(:test_redis_url)  { "redis://redishost:#{redis_port}"}
+
+  before(:each) do
+    stub_env(environment_config_file_name, Rails.root.join(config_file_name))
+    clear_raw_config
+  end
+
+  after(:each) do
+    clear_raw_config
+  end
+
+  describe '.params' do
+    subject { described_class.params }
+
+    it 'withstands mutation' do
+      params1 = described_class.params
+      params2 = described_class.params
+      params1[:foo] = :bar
+
+      expect(params2).not_to have_key(:foo)
+    end
+
+    context 'when url contains unix socket reference' do
+      context 'with old format' do
+        let(:config_file_name) { config_old_format_socket }
+
+        it 'returns path key instead' do
+          is_expected.to include(path: old_socket_path)
+          is_expected.not_to have_key(:url)
+        end
+      end
+
+      context 'with new format' do
+        let(:config_file_name) { config_new_format_socket }
+
+        it 'returns path key instead' do
+          is_expected.to include(path: new_socket_path)
+          is_expected.not_to have_key(:url)
+        end
+      end
+    end
+
+    context 'when url is host based' do
+      context 'with old format' do
+        let(:config_file_name) { config_old_format_host }
+
+        it 'returns hash with host, port, db, and password' do
+          is_expected.to include(host: 'localhost', password: 'mypassword', port: redis_port, db: redis_database)
+          is_expected.not_to have_key(:url)
+        end
+      end
+
+      context 'with new format' do
+        let(:config_file_name) { config_new_format_host }
+
+        it 'returns hash with host, port, db, and password' do
+          is_expected.to include(host: 'localhost', password: 'mynewpassword', port: redis_port, db: redis_database)
+          is_expected.not_to have_key(:url)
+        end
+      end
+    end
+  end
+
+  describe '.url' do
+    it 'withstands mutation' do
+      url1 = described_class.url
+      url2 = described_class.url
+      url1 << 'foobar'
+
+      expect(url2).not_to end_with('foobar')
+    end
+
+    context 'when yml file with env variable' do
+      let(:config_file_name) { config_with_environment_variable_inside }
+
+      before  do
+        stub_env(config_env_variable_url, test_redis_url)
+      end
+
+      it 'reads redis url from env variable' do
+        expect(described_class.url).to eq test_redis_url
+      end
+    end
+  end
+
+  describe '._raw_config' do
+    subject { described_class._raw_config }
+    let(:config_file_name) { '/var/empty/doesnotexist' }
+
+    it 'should be frozen' do
+      expect(subject).to be_frozen
+    end
+
+    it 'returns false when the file does not exist' do
+      expect(subject).to eq(false)
+    end
+  end
+
+  describe '.with' do
+    before do
+      clear_pool
+    end
+
+    after do
+      clear_pool
+    end
+
+    context 'when running not on sidekiq workers' do
+      before do
+        allow(Sidekiq).to receive(:server?).and_return(false)
+      end
+
+      it 'instantiates a connection pool with size 5' do
+        expect(ConnectionPool).to receive(:new).with(size: 5).and_call_original
+
+        described_class.with { |_redis_shared_example| true }
+      end
+    end
+
+    context 'when running on sidekiq workers' do
+      before do
+        allow(Sidekiq).to receive(:server?).and_return(true)
+        allow(Sidekiq).to receive(:options).and_return({ concurrency: 18 })
+      end
+
+      it 'instantiates a connection pool with a size based on the concurrency of the worker' do
+        expect(ConnectionPool).to receive(:new).with(size: 18 + 5).and_call_original
+
+        described_class.with { |_redis_shared_example| true }
+      end
+    end
+  end
+
+  describe '#sentinels' do
+    subject { described_class.new(Rails.env).sentinels }
+
+    context 'when sentinels are defined' do
+      let(:config_file_name) { config_new_format_host }
+
+      it 'returns an array of hashes with host and port keys' do
+        is_expected.to include(host: 'localhost', port: sentinel_port)
+        is_expected.to include(host: 'slave2', port: sentinel_port)
+      end
+    end
+
+    context 'when sentinels are not defined' do
+      let(:config_file_name) { config_old_format_host }
+
+      it 'returns nil' do
+        is_expected.to be_nil
+      end
+    end
+  end
+
+  describe '#sentinels?' do
+    subject { described_class.new(Rails.env).sentinels? }
+
+    context 'when sentinels are defined' do
+      let(:config_file_name) { config_new_format_host }
+
+      it 'returns true' do
+        is_expected.to be_truthy
+      end
+    end
+
+    context 'when sentinels are not defined' do
+      let(:config_file_name) { config_old_format_host }
+
+      it 'returns false' do
+        is_expected.to be_falsey
+      end
+    end
+  end
+
+  describe '#raw_config_hash' do
+    it 'returns default redis url when no config file is present' do
+      expect(subject).to receive(:fetch_config) { false }
+
+      expect(subject.send(:raw_config_hash)).to eq(url: class_redis_url )
+    end
+
+    it 'returns old-style single url config in a hash' do
+      expect(subject).to receive(:fetch_config) { test_redis_url }
+      expect(subject.send(:raw_config_hash)).to eq(url: test_redis_url)
+    end
+  end
+
+  describe '#fetch_config' do
+    it 'returns false when no config file is present' do
+      allow(described_class).to receive(:_raw_config) { false }
+
+      expect(subject.send(:fetch_config)).to be_falsey
+    end
+  end
+
+  def clear_raw_config
+    described_class.remove_instance_variable(:@_raw_config)
+  rescue NameError
+    # raised if @_raw_config was not set; ignore
+  end
+
+  def clear_pool
+    described_class.remove_instance_variable(:@pool)
+  rescue NameError
+    # raised if @pool was not set; ignore
+  end
+end