Add initializer for unleash client

Add logger for unleash client

4 files changed, 95 insertions, 0 deletions

diff --git a/config/initializers/unleash.rb b/config/initializers/unleash.rb
new file mode 100644
index 00000000000..4ece403a338
--- /dev/null
+++ b/config/initializers/unleash.rb
@@ -0,0 +1,11 @@
+server_url = ENV['GITLAB_FEATURE_FLAG_SERVER_URL']
+instance_id = ENV['GITLAB_FEATURE_FLAG_INSTANCE_ID']
+
+if RunningWebServer.unicorn? && server_url && instance_id
+  Unleash.configure do |config|
+    config.url = server_url
+    config.instance_id = instance_id
+    config.app_name = Rails.env
+    config.logger = Gitlab::UnleashClient::Logger.build
+  end
+end
diff --git a/lib/gitlab/unleash_client/logger.rb b/lib/gitlab/unleash_client/logger.rb
new file mode 100644
index 00000000000..982cce20073
--- /dev/null
+++ b/lib/gitlab/unleash_client/logger.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module UnleashClient
+    class Logger < ::Gitlab::Logger
+      def self.file_name_noext
+        'unleash_client'
+      end
+    end
+  end
+end
diff --git a/lib/running_web_server.rb b/lib/running_web_server.rb
new file mode 100644
index 00000000000..9de196f8210
--- /dev/null
+++ b/lib/running_web_server.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class RunningWebServer
+  def self.unicorn?
+    !!defined?(::Unicorn)
+  end
+
+  def self.puma?
+    !!defined?(::Puma)
+  end
+end
diff --git a/spec/initializers/unleash_spec.rb b/spec/initializers/unleash_spec.rb
new file mode 100644
index 00000000000..6be760595ea
--- /dev/null
+++ b/spec/initializers/unleash_spec.rb
@@ -0,0 +1,62 @@
+require 'spec_helper'
+require_relative '../../lib/running_web_server'
+
+describe 'Unleash initializer' do
+  def load_initializer
+    load Rails.root.join('config/initializers/unleash.rb')
+  end
+
+  before do
+    allow(ENV).to receive(:[]).and_call_original
+    Unleash.configuration = nil
+  end
+
+  context 'when the web server is unicorn' do
+    before do
+      allow(RunningWebServer).to receive(:unicorn?).and_return(true)
+    end
+
+    it 'sets configuration based on environment variables' do
+      allow(ENV).to receive(:[]).with('GITLAB_FEATURE_FLAG_SERVER_URL').and_return('some server url')
+      allow(ENV).to receive(:[]).with('GITLAB_FEATURE_FLAG_INSTANCE_ID').and_return('some instance id')
+
+      load_initializer
+
+      expect(Unleash.configuration.url).to eq('some server url')
+      expect(Unleash.configuration.instance_id).to eq('some instance id')
+      expect(Unleash.configuration.app_name).to eq(Rails.env)
+      expect(Unleash.configuration.logger).to be_an_instance_of(Gitlab::UnleashClient::Logger)
+    end
+
+    it 'does not set the configuration without a server url' do
+      allow(ENV).to receive(:[]).with('GITLAB_FEATURE_FLAG_INSTANCE_ID').and_return('some instance id')
+
+      load_initializer
+
+      expect(Unleash.configuration).to be_nil
+    end
+
+    it 'does not set the configuration without an instance id' do
+      allow(ENV).to receive(:[]).with('GITLAB_FEATURE_FLAG_SERVER_URL').and_return('some server url')
+
+      load_initializer
+
+      expect(Unleash.configuration).to be_nil
+    end
+  end
+
+  context 'when the web server is not unicorn' do
+    before do
+      allow(RunningWebServer).to receive(:unicorn?).and_return(false)
+    end
+
+    it 'does not load the config' do
+      allow(ENV).to receive(:[]).with('GITLAB_FEATURE_FLAG_SERVER_URL').and_return('some server url')
+      allow(ENV).to receive(:[]).with('GITLAB_FEATURE_FLAG_INSTANCE_ID').and_return('some instance id')
+
+      load_initializer
+
+      expect(Unleash.configuration).to be_nil
+    end
+  end
+end