add metrics

metrics/metrics.go

@@ -0,0 +1,135 @@
+package metrics
+
+import (
+	"os"
+
+	"github.com/go-gost/core/metrics"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type promMetrics struct {
+	host       string
+	gauges     map[metrics.MetricName]*prometheus.GaugeVec
+	counters   map[metrics.MetricName]*prometheus.CounterVec
+	histograms map[metrics.MetricName]*prometheus.HistogramVec
+}
+
+func NewMetrics() metrics.Metrics {
+	host, _ := os.Hostname()
+	m := &promMetrics{
+		host: host,
+		gauges: map[metrics.MetricName]*prometheus.GaugeVec{
+			metrics.MetricServicesGauge: prometheus.NewGaugeVec(
+				prometheus.GaugeOpts{
+					Name: string(metrics.MetricServicesGauge),
+					Help: "Current number of services",
+				},
+				[]string{"host"}),
+			metrics.MetricServiceRequestsInFlightGauge: prometheus.NewGaugeVec(
+				prometheus.GaugeOpts{
+					Name: string(metrics.MetricServiceRequestsInFlightGauge),
+					Help: "Current in-flight requests",
+				},
+				[]string{"host", "service"}),
+		},
+		counters: map[metrics.MetricName]*prometheus.CounterVec{
+			metrics.MetricServiceRequestsCounter: prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Name: string(metrics.MetricServiceRequestsCounter),
+					Help: "Total number of requests",
+				},
+				[]string{"host", "service"}),
+			metrics.MetricServiceTransferInputBytesCounter: prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Name: string(metrics.MetricServiceTransferInputBytesCounter),
+					Help: "Total service input data transfer size in bytes",
+				},
+				[]string{"host", "service"}),
+			metrics.MetricServiceTransferOutputBytesCounter: prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Name: string(metrics.MetricServiceTransferOutputBytesCounter),
+					Help: "Total service output data transfer size in bytes",
+				},
+				[]string{"host", "service"}),
+			metrics.MetricServiceHandlerErrorsCounter: prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Name: string(metrics.MetricServiceHandlerErrorsCounter),
+					Help: "Total service handler errors",
+				},
+				[]string{"host", "service"}),
+			metrics.MetricChainErrorsCounter: prometheus.NewCounterVec(
+				prometheus.CounterOpts{
+					Name: string(metrics.MetricChainErrorsCounter),
+					Help: "Total chain errors",
+				},
+				[]string{"host", "chain"}),
+		},
+		histograms: map[metrics.MetricName]*prometheus.HistogramVec{
+			metrics.MetricServiceRequestsDurationObserver: prometheus.NewHistogramVec(
+				prometheus.HistogramOpts{
+					Name: string(metrics.MetricServiceRequestsDurationObserver),
+					Help: "Distribution of request latencies",
+					Buckets: []float64{
+						.005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10, 15, 30, 60,
+					},
+				},
+				[]string{"host", "service"}),
+			metrics.MetricNodeConnectDurationObserver: prometheus.NewHistogramVec(
+				prometheus.HistogramOpts{
+					Name: string(metrics.MetricNodeConnectDurationObserver),
+					Help: "Distribution of chain node connect latencies",
+					Buckets: []float64{
+						.01, .05, .1, .25, .5, 1, 1.5, 2, 5, 10, 15, 30, 60,
+					},
+				},
+				[]string{"host", "chain", "node"}),
+		},
+	}
+	for k := range m.gauges {
+		prometheus.MustRegister(m.gauges[k])
+	}
+	for k := range m.counters {
+		prometheus.MustRegister(m.counters[k])
+	}
+	for k := range m.histograms {
+		prometheus.MustRegister(m.histograms[k])
+	}
+
+	return m
+}
+
+func (m *promMetrics) Gauge(name metrics.MetricName, labels metrics.Labels) metrics.Gauge {
+	v, ok := m.gauges[name]
+	if !ok {
+		return nil
+	}
+	if labels == nil {
+		labels = metrics.Labels{}
+	}
+	labels["host"] = m.host
+	return v.With(prometheus.Labels(labels))
+}
+
+func (m *promMetrics) Counter(name metrics.MetricName, labels metrics.Labels) metrics.Counter {
+	v, ok := m.counters[name]
+	if !ok {
+		return nil
+	}
+	if labels == nil {
+		labels = metrics.Labels{}
+	}
+	labels["host"] = m.host
+	return v.With(prometheus.Labels(labels))
+}
+
+func (m *promMetrics) Observer(name metrics.MetricName, labels metrics.Labels) metrics.Observer {
+	v, ok := m.histograms[name]
+	if !ok {
+		return nil
+	}
+	if labels == nil {
+		labels = metrics.Labels{}
+	}
+	labels["host"] = m.host
+	return v.With(prometheus.Labels(labels))
+}

metrics/service/service.go

@@ -0,0 +1,65 @@
+package service
+
+import (
+	"net"
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+const (
+	DefaultPath = "/metrics"
+)
+
+type options struct {
+	path string
+}
+
+type Option func(*options)
+
+func PathOption(path string) Option {
+	return func(o *options) {
+		o.path = path
+	}
+}
+
+type Service struct {
+	s  *http.Server
+	ln net.Listener
+}
+
+func NewService(addr string, opts ...Option) (*Service, error) {
+	ln, err := net.Listen("tcp", addr)
+	if err != nil {
+		return nil, err
+	}
+
+	var options options
+	for _, opt := range opts {
+		opt(&options)
+	}
+	if options.path == "" {
+		options.path = DefaultPath
+	}
+
+	mux := http.NewServeMux()
+	mux.Handle(options.path, promhttp.Handler())
+	return &Service{
+		s: &http.Server{
+			Handler: mux,
+		},
+		ln: ln,
+	}, nil
+}
+
+func (s *Service) Serve() error {
+	return s.s.Serve(s.ln)
+}
+
+func (s *Service) Addr() net.Addr {
+	return s.ln.Addr()
+}
+
+func (s *Service) Close() error {
+	return s.s.Close()
+}