diff options
Diffstat (limited to 'spec/metrics_server/metrics_server_spec.rb')
-rw-r--r-- | spec/metrics_server/metrics_server_spec.rb | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/spec/metrics_server/metrics_server_spec.rb b/spec/metrics_server/metrics_server_spec.rb new file mode 100644 index 00000000000..4e3c6900875 --- /dev/null +++ b/spec/metrics_server/metrics_server_spec.rb @@ -0,0 +1,109 @@ +# frozen_string_literal: true + +require 'fast_spec_helper' + +require_relative '../../metrics_server/metrics_server' +require_relative '../support/helpers/next_instance_of' + +RSpec.describe MetricsServer do # rubocop:disable RSpec/FilePath + include NextInstanceOf + + before do + # We do not want this to have knock-on effects on the test process. + allow(Gitlab::ProcessManagement).to receive(:modify_signals) + end + + describe '.spawn' do + context 'when in parent process' do + it 'forks into a new process and detaches it' do + expect(Process).to receive(:fork).and_return(99) + expect(Process).to receive(:detach).with(99) + + described_class.spawn('sidekiq', metrics_dir: 'path/to/metrics') + end + end + + context 'when in child process' do + before do + # This signals the process that it's "inside" the fork + expect(Process).to receive(:fork).and_return(nil) + expect(Process).not_to receive(:detach) + end + + it 'starts the metrics server with the given arguments' do + expect_next_instance_of(MetricsServer) do |server| + expect(server).to receive(:start) + end + + described_class.spawn('sidekiq', metrics_dir: 'path/to/metrics') + end + + it 'resets signal handlers from parent process' do + expect(Gitlab::ProcessManagement).to receive(:modify_signals).with(%i[A B], 'DEFAULT') + + described_class.spawn('sidekiq', metrics_dir: 'path/to/metrics', trapped_signals: %i[A B]) + end + end + end + + describe '#start' do + let(:exporter_class) { Class.new(Gitlab::Metrics::Exporter::BaseExporter) } + let(:exporter_double) { double('fake_exporter', start: true) } + let(:prometheus_config) { ::Prometheus::Client.configuration } + let(:metrics_dir) { Dir.mktmpdir } + let(:settings) { { "fake_exporter" => { "enabled" => true } } } + let!(:old_metrics_dir) { prometheus_config.multiprocess_files_dir } + + subject(:metrics_server) { described_class.new('fake', metrics_dir, true)} + + before do + stub_const('Gitlab::Metrics::Exporter::FakeExporter', exporter_class) + expect(exporter_class).to receive(:instance).with(settings['fake_exporter'], synchronous: true).and_return(exporter_double) + expect(Settings).to receive(:monitoring).and_return(settings) + end + + after do + Gitlab::Metrics.reset_registry! + FileUtils.rm_rf(metrics_dir, secure: true) + prometheus_config.multiprocess_files_dir = old_metrics_dir + end + + it 'configures ::Prometheus::Client' do + metrics_server.start + + expect(prometheus_config.multiprocess_files_dir).to eq metrics_dir + end + + it 'ensures that metrics directory exists in correct mode (0700)' do + expect(FileUtils).to receive(:mkdir_p).with(metrics_dir, mode: 0700) + + metrics_server.start + end + + context 'when wipe_metrics_dir is true' do + subject(:metrics_server) { described_class.new('fake', metrics_dir, true)} + + it 'removes any old metrics files' do + FileUtils.touch("#{metrics_dir}/remove_this.db") + + expect { metrics_server.start }.to change { Dir.empty?(metrics_dir) }.from(false).to(true) + end + end + + context 'when wipe_metrics_dir is false' do + subject(:metrics_server) { described_class.new('fake', metrics_dir, false)} + + it 'does not remove any old metrics files' do + FileUtils.touch("#{metrics_dir}/remove_this.db") + + expect { metrics_server.start }.not_to change { Dir.empty?(metrics_dir) }.from(false) + end + end + + it 'starts a metrics server' do + expect(exporter_double).to receive(:start) + + metrics_server.start + end + end +end |