1 files changed, 117 insertions, 0 deletions
diff --git a/spec/lib/prometheus/pid_provider_spec.rb b/spec/lib/prometheus/pid_provider_spec.rb
new file mode 100644
index 00000000000..ba843b27254
--- /dev/null
+++ b/spec/lib/prometheus/pid_provider_spec.rb
@@ -0,0 +1,117 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+
+describe Prometheus::PidProvider do
+  describe '.worker_id' do
+    subject { described_class.worker_id }
+
+    let(:sidekiq_module) { Module.new }
+
+    before do
+      allow(sidekiq_module).to receive(:server?).and_return(false)
+      stub_const('Sidekiq', sidekiq_module)
+    end
+
+    context 'when running in Sidekiq server mode' do
+      before do
+        expect(Sidekiq).to receive(:server?).and_return(true)
+      end
+
+      it { is_expected.to eq 'sidekiq' }
+    end
+
+    context 'when running in Unicorn mode' do
+      before do
+        stub_const('Unicorn::Worker', Class.new)
+        hide_const('Puma')
+
+        expect(described_class).to receive(:process_name)
+          .at_least(:once)
+          .and_return(process_name)
+      end
+
+      context 'when unicorn master is specified in process name' do
+        context 'when running in Omnibus' do
+          context 'before the process was renamed' do
+            let(:process_name) { "/opt/gitlab/embedded/bin/unicorn"}
+
+            it { is_expected.to eq 'unicorn_master' }
+          end
+
+          context 'after the process was renamed' do
+            let(:process_name) { "unicorn master -D -E production -c /var/opt/gitlab/gitlab-rails/etc/unicorn.rb /opt/gitlab/embedded/service/gitlab-rails/config.ru" }
+
+            it { is_expected.to eq 'unicorn_master' }
+          end
+        end
+
+        context 'when in development env' do
+          context 'before the process was renamed' do
+            let(:process_name) { "path_to_bindir/bin/unicorn_rails"}
+
+            it { is_expected.to eq 'unicorn_master' }
+          end
+
+          context 'after the process was renamed' do
+            let(:process_name) { "unicorn_rails master -c /gitlab_dir/config/unicorn.rb -E development" }
+
+            it { is_expected.to eq 'unicorn_master' }
+          end
+        end
+      end
+
+      context 'when unicorn worker id is specified in process name' do
+        context 'when running in Omnibus' do
+          let(:process_name) { "unicorn worker[1] -D -E production -c /var/opt/gitlab/gitlab-rails/etc/unicorn.rb /opt/gitlab/embedded/service/gitlab-rails/config.ru" }
+
+          it { is_expected.to eq 'unicorn_1' }
+        end
+
+        context 'when in development env' do
+          let(:process_name) { "unicorn_rails worker[1] -c gitlab_dir/config/unicorn.rb -E development" }
+
+          it { is_expected.to eq 'unicorn_1' }
+        end
+      end
+
+      context 'when no specified unicorn master or worker id in process name' do
+        let(:process_name) { "bin/unknown_process"}
+
+        it { is_expected.to eq "process_#{Process.pid}" }
+      end
+    end
+
+    context 'when running in Puma mode' do
+      before do
+        stub_const('Puma', Module.new)
+        hide_const('Unicorn::Worker')
+
+        expect(described_class).to receive(:process_name)
+          .at_least(:once)
+          .and_return(process_name)
+      end
+
+      context 'when cluster worker id is specified in process name' do
+        let(:process_name) { 'puma: cluster worker 1: 17483 [gitlab-puma-worker]' }
+
+        it { is_expected.to eq 'puma_1' }
+      end
+
+      context 'when no worker id is specified in process name' do
+        let(:process_name) { 'bin/puma' }
+
+        it { is_expected.to eq 'puma_master' }
+      end
+    end
+
+    context 'when running in unknown mode' do
+      before do
+        hide_const('Puma')
+        hide_const('Unicorn::Worker')
+      end
+
+      it { is_expected.to eq "process_#{Process.pid}" }
+    end
+  end
+end