# frozen_string_literal: true

require 'spec_helper'

require_relative '../../../metrics_server/metrics_server'

# End-to-end tests for the metrics server process we use to serve metrics
# from forking applications (Sidekiq, Puma) to the Prometheus scraper.
RSpec.describe 'bin/metrics-server', :aggregate_failures do
  let(:config_file) { Tempfile.new('gitlab.yml') }
  let(:config) do
    {
      'test' => {
        'monitoring' => {
          'web_exporter' => {
            'address' => 'localhost',
            'enabled' => true,
            'port' => 3807
          },
          'sidekiq_exporter' => {
            'address' => 'localhost',
            'enabled' => true,
            'port' => 3807
          }
        }
      }
    }
  end

  %w(puma sidekiq).each do |target|
    context "with a running server targeting #{target}" do
      let(:metrics_dir) { Dir.mktmpdir }

      before do
        # We need to send a request to localhost
        WebMock.allow_net_connect!

        config_file.write(YAML.dump(config))
        config_file.close

        @pid = MetricsServer.spawn(target, metrics_dir: metrics_dir, gitlab_config: config_file.path, wipe_metrics_dir: true)
      end

      after do
        webmock_enable!

        if @pid
          pgrp = Process.getpgid(@pid)

          Timeout.timeout(10) do
            Process.kill('TERM', -pgrp)
            Process.waitpid(@pid)
          end

          expect(Gitlab::ProcessManagement.process_alive?(@pid)).to be(false)
        end
      rescue Errno::ESRCH => _
        # 'No such process' means the process died before
      ensure
        config_file.unlink
        FileUtils.rm_rf(metrics_dir, secure: true)
      end

      it 'serves /metrics endpoint' do
        expect do
          Timeout.timeout(10) do
            http_ok = false
            until http_ok
              sleep 1
              response = Gitlab::HTTP.try_get("http://localhost:3807/metrics", allow_local_requests: true)
              http_ok = response&.success?
            end
          end
        end.not_to raise_error
      end
    end
  end
end