Add sidekiq metrics endpoint and add http server to sidekiq

3 files changed, 205 insertions, 1 deletions

diff --git a/spec/lib/gitlab/daemon_spec.rb b/spec/lib/gitlab/daemon_spec.rb
new file mode 100644
index 00000000000..c519984a267
--- /dev/null
+++ b/spec/lib/gitlab/daemon_spec.rb
@@ -0,0 +1,103 @@
+require 'spec_helper'
+
+describe Gitlab::Daemon do
+  subject { described_class.new }
+
+  before do
+    allow(subject).to receive(:start_working)
+    allow(subject).to receive(:stop_working)
+  end
+
+  describe '.instance' do
+    before do
+      allow(Kernel).to receive(:at_exit)
+    end
+
+    after(:each) do
+      described_class.instance_variable_set(:@instance, nil)
+    end
+
+    it 'provides instance of Daemon' do
+      expect(described_class.instance).to be_instance_of(described_class)
+    end
+
+    it 'subsequent invocations provide the same instance' do
+      expect(described_class.instance).to eq(described_class.instance)
+    end
+
+    it 'creates at_exit hook when instance is created' do
+      expect(described_class.instance).not_to be_nil
+
+      expect(Kernel).to have_received(:at_exit)
+    end
+  end
+
+  describe 'when Daemon is enabled' do
+    before do
+      allow(subject).to receive(:enabled?).and_return(true)
+    end
+
+    describe 'when Daemon is stopped' do
+      describe '#start' do
+        it 'starts the Daemon' do
+          expect { subject.start.join }.to change { subject.thread? }.from(false).to(true)
+
+          expect(subject).to have_received(:start_working)
+        end
+      end
+
+      describe '#stop' do
+        it "doesn't shutdown stopped Daemon" do
+          expect { subject.stop }.not_to change { subject.thread? }
+
+          expect(subject).not_to have_received(:start_working)
+        end
+      end
+    end
+
+    describe 'when Daemon is running' do
+      before do
+        subject.start.join
+      end
+
+      describe '#start' do
+        it "doesn't start running Daemon" do
+          expect { subject.start.join }.not_to change { subject.thread? }
+
+          expect(subject).to have_received(:start_working).once
+        end
+      end
+
+      describe '#stop' do
+        it 'shutdowns Daemon' do
+          expect { subject.stop }.to change { subject.thread? }.from(true).to(false)
+
+          expect(subject).to have_received(:stop_working)
+        end
+      end
+    end
+  end
+
+  describe 'when Daemon is disabled' do
+    before do
+      allow(subject).to receive(:enabled?).and_return(false)
+    end
+
+    describe '#start' do
+      it "doesn't start working" do
+        expect(subject.start).to be_nil
+        expect { subject.start }.not_to change { subject.thread? }
+
+        expect(subject).not_to have_received(:start_working)
+      end
+    end
+
+    describe '#stop' do
+      it "doesn't stop working" do
+        expect { subject.stop }.not_to change { subject.thread? }
+
+        expect(subject).not_to have_received(:stop_working)
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/metrics/influx_sampler_spec.rb b/spec/lib/gitlab/metrics/influx_sampler_spec.rb
index 0bc68d64276..999a9536d82 100644
--- a/spec/lib/gitlab/metrics/influx_sampler_spec.rb
+++ b/spec/lib/gitlab/metrics/influx_sampler_spec.rb
@@ -11,7 +11,7 @@ describe Gitlab::Metrics::InfluxSampler do
     it 'runs once and gathers a sample at a given interval' do
       expect(sampler).to receive(:sleep).with(a_kind_of(Numeric)).twice
       expect(sampler).to receive(:sample).once
-      expect(sampler).to receive(:running).and_return(false, true, false)
+      expect(sampler).to receive(:running).and_return(true, false)
 
       sampler.start.join
     end
diff --git a/spec/lib/gitlab/metrics/sidekiq_metrics_exporter_spec.rb b/spec/lib/gitlab/metrics/sidekiq_metrics_exporter_spec.rb
new file mode 100644
index 00000000000..6721e02fb85
--- /dev/null
+++ b/spec/lib/gitlab/metrics/sidekiq_metrics_exporter_spec.rb
@@ -0,0 +1,101 @@
+require 'spec_helper'
+
+describe Gitlab::Metrics::SidekiqMetricsExporter do
+  let(:exporter) { described_class.new }
+  let(:server) { double('server') }
+
+  before do
+    allow(::WEBrick::HTTPServer).to receive(:new).and_return(server)
+    allow(server).to receive(:mount)
+    allow(server).to receive(:start)
+    allow(server).to receive(:shutdown)
+  end
+
+  describe 'when exporter is enabled' do
+    before do
+      allow(Settings.monitoring.sidekiq_exporter).to receive(:enabled).and_return(true)
+    end
+
+    describe 'when exporter is stopped' do
+      describe '#start' do
+        it 'starts the exporter' do
+          expect { exporter.start.join }.to change { exporter.thread? }.from(false).to(true)
+
+          expect(server).to have_received(:start)
+        end
+
+        describe 'with custom settings' do
+          let(:port) { 99999 }
+          let(:address) { 'sidekiq_exporter_address' }
+
+          before do
+            allow(Settings.monitoring.sidekiq_exporter).to receive(:port).and_return(port)
+            allow(Settings.monitoring.sidekiq_exporter).to receive(:address).and_return(address)
+          end
+
+          it 'starts server with port and address from settings' do
+            exporter.start.join
+
+            expect(::WEBrick::HTTPServer).to have_received(:new).with(
+              Port: port,
+              BindAddress: address
+            )
+          end
+        end
+      end
+
+      describe '#stop' do
+        it "doesn't shutdown stopped server" do
+          expect { exporter.stop }.not_to change { exporter.thread? }
+
+          expect(server).not_to have_received(:shutdown)
+        end
+      end
+    end
+
+    describe 'when exporter is running' do
+      before do
+        exporter.start.join
+      end
+
+      describe '#start' do
+        it "doesn't start running server" do
+          expect { exporter.start.join }.not_to change { exporter.thread? }
+
+          expect(server).to have_received(:start).once
+        end
+      end
+
+      describe '#stop' do
+        it 'shutdowns server' do
+          expect { exporter.stop }.to change { exporter.thread? }.from(true).to(false)
+
+          expect(server).to have_received(:shutdown)
+        end
+      end
+    end
+  end
+
+  describe 'when exporter is disabled' do
+    before do
+      allow(Settings.monitoring.sidekiq_exporter).to receive(:enabled).and_return(false)
+    end
+
+    describe '#start' do
+      it "doesn't start" do
+        expect(exporter.start).to be_nil
+        expect { exporter.start }.not_to change { exporter.thread? }
+
+        expect(server).not_to have_received(:start)
+      end
+    end
+
+    describe '#stop' do
+      it "doesn't shutdown" do
+        expect { exporter.stop }.not_to change { exporter.thread? }
+
+        expect(server).not_to have_received(:shutdown)
+      end
+    end
+  end
+end