Adds new metrics for unicorn monitoring

This adds new metrics for monitoring unicorn. These metrics include
process_cpu_seconds_total, process_start_time_seconds, process_max_fds,
and unicorn_workers.

2 files changed, 46 insertions, 5 deletions

diff --git a/spec/lib/gitlab/metrics/samplers/unicorn_sampler_spec.rb b/spec/lib/gitlab/metrics/samplers/unicorn_sampler_spec.rb
index 4b03f3c2532..4470dc3ee93 100644
--- a/spec/lib/gitlab/metrics/samplers/unicorn_sampler_spec.rb
+++ b/spec/lib/gitlab/metrics/samplers/unicorn_sampler_spec.rb
@@ -39,8 +39,8 @@ describe Gitlab::Metrics::Samplers::UnicornSampler do
         it 'updates metrics type unix and with addr' do
           labels = { socket_type: 'unix', socket_address: socket_address }
 
-          expect(subject).to receive_message_chain(:unicorn_active_connections, :set).with(labels, 'active')
-          expect(subject).to receive_message_chain(:unicorn_queued_connections, :set).with(labels, 'queued')
+          expect(subject.metrics[:unicorn_active_connections]).to receive(:set).with(labels, 'active')
+          expect(subject.metrics[:unicorn_queued_connections]).to receive(:set).with(labels, 'queued')
 
           subject.sample
         end
@@ -50,7 +50,6 @@ describe Gitlab::Metrics::Samplers::UnicornSampler do
     context 'unicorn listens on tcp sockets' do
       let(:tcp_socket_address) { '0.0.0.0:8080' }
       let(:tcp_sockets) { [tcp_socket_address] }
-
       before do
         allow(unicorn).to receive(:listener_names).and_return(tcp_sockets)
       end
@@ -71,13 +70,37 @@ describe Gitlab::Metrics::Samplers::UnicornSampler do
         it 'updates metrics type unix and with addr' do
           labels = { socket_type: 'tcp', socket_address: tcp_socket_address }
 
-          expect(subject).to receive_message_chain(:unicorn_active_connections, :set).with(labels, 'active')
-          expect(subject).to receive_message_chain(:unicorn_queued_connections, :set).with(labels, 'queued')
+          expect(subject.metrics[:unicorn_active_connections]).to receive(:set).with(labels, 'active')
+          expect(subject.metrics[:unicorn_queued_connections]).to receive(:set).with(labels, 'queued')
 
           subject.sample
         end
       end
     end
+
+    context 'additional metrics' do
+      let(:cpu_time) { 3.14 }
+      let(:process_start_time) { 19100.24 }
+      let(:process_max_fds) { 1024 }
+      let(:unicorn_workers) { 2 }
+
+      before do
+        allow(unicorn).to receive(:listener_names).and_return([""])
+        allow(::Gitlab::Metrics::System).to receive(:cpu_time).and_return(cpu_time)
+        allow(::Gitlab::Metrics::System).to receive(:process_start_time).and_return(process_start_time)
+        allow(::Gitlab::Metrics::System).to receive(:max_open_file_descriptors).and_return(process_max_fds)
+        allow(subject).to receive(:unicorn_workers_count).and_return(unicorn_workers)
+      end
+
+      it "sets additional metrics" do
+        expect(subject.metrics[:process_cpu_seconds_total]).to receive(:set).with({ pid: nil }, cpu_time)
+        expect(subject.metrics[:process_start_time_seconds]).to receive(:set).with({ pid: nil }, process_start_time)
+        expect(subject.metrics[:process_max_fds]).to receive(:set).with({ pid: nil }, process_max_fds)
+        expect(subject.metrics[:unicorn_workers]).to receive(:set).with({}, unicorn_workers)
+
+        subject.sample
+      end
+    end
   end
 
   describe '#start' do
diff --git a/spec/lib/gitlab/metrics/system_spec.rb b/spec/lib/gitlab/metrics/system_spec.rb
index 14afcdf5daa..2de6821bb79 100644
--- a/spec/lib/gitlab/metrics/system_spec.rb
+++ b/spec/lib/gitlab/metrics/system_spec.rb
@@ -13,6 +13,12 @@ describe Gitlab::Metrics::System do
         expect(described_class.file_descriptor_count).to be > 0
       end
     end
+
+    describe '.max_open_file_descriptors' do
+      it 'returns the max allowed open file descriptors' do
+        expect(described_class.max_open_file_descriptors).to be > 0
+      end
+    end
   else
     describe '.memory_usage' do
       it 'returns 0.0' do
@@ -25,6 +31,12 @@ describe Gitlab::Metrics::System do
         expect(described_class.file_descriptor_count).to eq(0)
       end
     end
+
+    describe '.max_open_file_descriptors' do
+      it 'returns 0' do
+        expect(described_class.max_open_file_descriptors).to eq(0)
+      end
+    end
   end
 
   describe '.cpu_time' do
@@ -44,4 +56,10 @@ describe Gitlab::Metrics::System do
       expect(described_class.monotonic_time).to be_an(Float)
     end
   end
+
+  describe '.process_start_time' do
+    it 'returns a Float' do
+      expect(described_class.process_start_time).to be_an(Float)
+    end
+  end
 end