1 files changed, 180 insertions, 0 deletions
diff --git a/spec/lib/gitlab/metrics/exporter/base_exporter_spec.rb b/spec/lib/gitlab/metrics/exporter/base_exporter_spec.rb
new file mode 100644
index 00000000000..47ec69e2f45
--- /dev/null
+++ b/spec/lib/gitlab/metrics/exporter/base_exporter_spec.rb
@@ -0,0 +1,180 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Metrics::Exporter::BaseExporter do
+  let(:exporter) { described_class.new }
+  let(:log_filename) { File.join(Rails.root, 'log', 'sidekiq_exporter.log') }
+  let(:settings) { double('settings') }
+
+  before do
+    allow_any_instance_of(described_class).to receive(:log_filename).and_return(log_filename)
+    allow_any_instance_of(described_class).to receive(:settings).and_return(settings)
+  end
+
+  describe 'when exporter is enabled' do
+    before do
+      allow(::WEBrick::HTTPServer).to receive(:new).with(
+        Port: anything,
+        BindAddress: anything,
+        Logger: anything,
+        AccessLog: anything
+      ).and_call_original
+
+      allow(settings).to receive(:enabled).and_return(true)
+      allow(settings).to receive(:port).and_return(0)
+      allow(settings).to receive(:address).and_return('127.0.0.1')
+    end
+
+    after do
+      exporter.stop
+    end
+
+    describe 'when exporter is stopped' do
+      describe '#start' do
+        it 'starts the exporter' do
+          expect_any_instance_of(::WEBrick::HTTPServer).to receive(:start)
+
+          expect { exporter.start.join }.to change { exporter.thread? }.from(false).to(true)
+        end
+
+        describe 'with custom settings' do
+          let(:port) { 99999 }
+          let(:address) { 'sidekiq_exporter_address' }
+
+          before do
+            allow(settings).to receive(:port).and_return(port)
+            allow(settings).to receive(:address).and_return(address)
+          end
+
+          it 'starts server with port and address from settings' do
+            expect(::WEBrick::HTTPServer).to receive(:new).with(
+              Port: port,
+              BindAddress: address,
+              Logger: anything,
+              AccessLog: anything
+            ).and_wrap_original do |m, *args|
+              m.call(DoNotListen: true, Logger: args.first[:Logger])
+            end
+
+            allow_any_instance_of(::WEBrick::HTTPServer).to receive(:start)
+
+            exporter.start.join
+          end
+        end
+
+        describe 'when thread is not alive' do
+          it 'does close listeners' do
+            expect_any_instance_of(::WEBrick::HTTPServer).to receive(:start)
+            expect_any_instance_of(::WEBrick::HTTPServer).to receive(:listeners)
+              .and_call_original
+
+            expect { exporter.start.join }.to change { exporter.thread? }.from(false).to(true)
+
+            exporter.stop
+          end
+        end
+      end
+
+      describe '#stop' do
+        it "doesn't shutdown stopped server" do
+          expect_any_instance_of(::WEBrick::HTTPServer).not_to receive(:shutdown)
+
+          expect { exporter.stop }.not_to change { exporter.thread? }
+        end
+      end
+    end
+
+    describe 'when exporter is running' do
+      before do
+        exporter.start
+      end
+
+      describe '#start' do
+        it "doesn't start running server" do
+          expect_any_instance_of(::WEBrick::HTTPServer).not_to receive(:start)
+
+          expect { exporter.start }.not_to change { exporter.thread? }
+        end
+      end
+
+      describe '#stop' do
+        it 'shutdowns server' do
+          expect_any_instance_of(::WEBrick::HTTPServer).to receive(:shutdown)
+
+          expect { exporter.stop }.to change { exporter.thread? }.from(true).to(false)
+        end
+      end
+    end
+  end
+
+  describe 'request handling' do
+    using RSpec::Parameterized::TableSyntax
+
+    where(:method_class, :path, :http_status) do
+      Net::HTTP::Get | '/metrics' | 200
+      Net::HTTP::Get | '/liveness' | 200
+      Net::HTTP::Get | '/readiness' | 200
+      Net::HTTP::Get | '/' | 404
+    end
+
+    before do
+      allow(settings).to receive(:enabled).and_return(true)
+      allow(settings).to receive(:port).and_return(0)
+      allow(settings).to receive(:address).and_return('127.0.0.1')
+
+      # We want to wrap original method
+      # and run handling of requests
+      # in separate thread
+      allow_any_instance_of(::WEBrick::HTTPServer)
+        .to receive(:start).and_wrap_original do |m, *args|
+        Thread.new do
+          m.call(*args)
+        rescue IOError
+          # is raised as we close listeners
+        end
+      end
+
+      exporter.start.join
+    end
+
+    after do
+      exporter.stop
+    end
+
+    with_them do
+      let(:config) { exporter.server.config }
+      let(:request) { method_class.new(path) }
+
+      it 'responds with proper http_status' do
+        http = Net::HTTP.new(config[:BindAddress], config[:Port])
+        response = http.request(request)
+
+        expect(response.code).to eq(http_status.to_s)
+      end
+    end
+  end
+
+  describe 'when exporter is disabled' do
+    before do
+      allow(settings).to receive(:enabled).and_return(false)
+    end
+
+    describe '#start' do
+      it "doesn't start" do
+        expect_any_instance_of(::WEBrick::HTTPServer).not_to receive(:start)
+
+        expect(exporter.start).to be_nil
+        expect { exporter.start }.not_to change { exporter.thread? }
+      end
+    end
+
+    describe '#stop' do
+      it "doesn't shutdown" do
+        expect_any_instance_of(::WEBrick::HTTPServer).not_to receive(:shutdown)
+
+        expect { exporter.stop }.not_to change { exporter.thread? }
+      end
+    end
+  end
+end