Function Start

monitoring/monitoring.go:234–301

Start deploys monitoring service which deploys Prometheus that monitors all InstrumentedRunnable instances in an environment created with AsInstrumented.

(env e2e.Environment, opts ...Option)

// Start deploys monitoring service which deploys Prometheus that monitors all
// InstrumentedRunnable instances in an environment created with AsInstrumented.
func Start(env e2e.Environment, opts ...Option) (_ *Service, err error) {
	opt := opt{
		scrapeInterval: 5 * time.Second,
		useCadvisor:    true,
	}
	for _, o := range opts {
		o(&opt)
	}

	// Expose metrics from the current process.
	metrics := opt.customRegistry
	if metrics == nil {
		metrics = prometheus.NewRegistry()
		metrics.MustRegister(
			collectors.NewGoCollector(),
			collectors.NewProcessCollector(collectors.ProcessCollectorOpts{}),
		)
	}

	m := http.NewServeMux()
	h := promhttp.HandlerFor(metrics, promhttp.HandlerOpts{})
	o := sync.Once{}
	scraped := make(chan struct{})
	m.Handle("/metrics", http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		o.Do(func() { close(scraped) })
		h.ServeHTTP(w, req)
	}))

	// Listen on all addresses, since we need to connect to it from docker container.
	list, err := net.Listen("tcp", "0.0.0.0:0")
	if err != nil {
		return nil, err
	}
	s := http.Server{Handler: m}

	go func() { _ = s.Serve(list) }()
	env.AddCloser(func() { _ = s.Close() })

	p := NewPrometheus(env, "monitoring", opt.customPromImage, nil)

	_, port, err := net.SplitHostPort(list.Addr().String())
	if err != nil {
		return nil, err
	}
	l := &listener{p: p, localAddr: net.JoinHostPort(env.HostAddr(), port), scrapeInterval: opt.scrapeInterval}
	if err := l.updateConfig(map[string]Instrumented{}); err != nil {
		return nil, err
	}
	env.AddListener(l)

	if opt.useCadvisor {
		c := newCadvisor(env, "cadvisor")
		if err := e2e.StartAndWaitReady(c); err != nil {
			return nil, errors.Wrap(err, "starting cadvisor and waiting until ready")
		}
	}
	if err := e2e.StartAndWaitReady(p); err != nil {
		return nil, errors.Wrap(err, "starting monitoring and waiting until ready")