application specific metrics

2 files changed, 114 insertions, 8 deletions

diff --git a/service/metrics/config.go b/service/metrics/config.go
index 799ba2d2..b93d8f50 100644
--- a/service/metrics/config.go
+++ b/service/metrics/config.go
@@ -1,23 +1,115 @@
 package metrics
 
-import "github.com/spiral/roadrunner/service"
+import (
+	"fmt"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/spiral/roadrunner/service"
+)
 
 type Config struct {
 	// Address to listen
 	Address string
 
-	// Metrics define application specific metrics.
-	Metrics map[string]Metric
+	// Collect define application specific metrics.
+	Collect map[string]Metric
 }
 
 // Metric describes single application specific metric.
 type Metric struct {
-	Type        string
-	Description string
-	Labels      []string
+	// Namespace of the metric.
+	Namespace string
+
+	// Subsystem of the metric.
+	Subsystem string
+
+	// Collector type (histogram, gauge, counter, summary).
+	Type string
+
+	// Help of collector.
+	Help string
+
+	// Labels for vectorized metrics.
+	Labels []string
+
+	// Buckets for histogram metric.
+	Buckets []float64
 }
 
 // Hydrate configuration.
 func (c *Config) Hydrate(cfg service.Config) error {
 	return cfg.Unmarshal(c)
 }
+
+// register application specific metrics.
+func (c *Config) registerMetrics() error {
+	if c.Collect == nil {
+		return nil
+	}
+
+	for name, m := range c.Collect {
+		var collector prometheus.Collector
+		switch m.Type {
+		case "histogram":
+			opts := prometheus.HistogramOpts{
+				Name:      name,
+				Namespace: m.Namespace,
+				Subsystem: m.Subsystem,
+				Help:      m.Help,
+				Buckets:   m.Buckets,
+			}
+
+			if len(m.Labels) != 0 {
+				collector = prometheus.NewHistogramVec(opts, m.Labels)
+			} else {
+				collector = prometheus.NewHistogram(opts)
+			}
+		case "gauge":
+			opts := prometheus.GaugeOpts{
+				Name:      name,
+				Namespace: m.Namespace,
+				Subsystem: m.Subsystem,
+				Help:      m.Help,
+			}
+
+			if len(m.Labels) != 0 {
+				collector = prometheus.NewGaugeVec(opts, m.Labels)
+			} else {
+				collector = prometheus.NewGauge(opts)
+			}
+		case "counter":
+			opts := prometheus.CounterOpts{
+				Name:      name,
+				Namespace: m.Namespace,
+				Subsystem: m.Subsystem,
+				Help:      m.Help,
+			}
+
+			if len(m.Labels) != 0 {
+				collector = prometheus.NewCounterVec(opts, m.Labels)
+			} else {
+				collector = prometheus.NewCounter(opts)
+			}
+		case "summary":
+			opts := prometheus.SummaryOpts{
+				Name:      name,
+				Namespace: m.Namespace,
+				Subsystem: m.Subsystem,
+				Help:      m.Help,
+			}
+
+			if len(m.Labels) != 0 {
+				collector = prometheus.NewSummaryVec(opts, m.Labels)
+			} else {
+				collector = prometheus.NewSummary(opts)
+			}
+		default:
+			return fmt.Errorf("invalid metric type %s", m.Type)
+		}
+
+		if err := prometheus.Register(collector); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
diff --git a/service/metrics/service.go b/service/metrics/service.go
index 9d2a3dad..2823b1a4 100644
--- a/service/metrics/service.go
+++ b/service/metrics/service.go
@@ -5,6 +5,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"net/http"
+	"sync"
 )
 
 // ID declares public service name.
@@ -13,6 +14,7 @@ const ID = "metrics"
 // Service to manage application metrics using Prometheus.
 type Service struct {
 	cfg  *Config
+	mu   sync.Mutex
 	http *http.Server
 }
 
@@ -41,13 +43,25 @@ func (s *Service) MustRegister(c prometheus.Collector) {
 
 // Serve prometheus metrics service.
 func (s *Service) Serve() error {
+	// register application specific metrics
+	if err := s.cfg.registerMetrics(); err != nil {
+		return err
+	}
+
+	s.mu.Lock()
 	s.http = &http.Server{Addr: s.cfg.Address, Handler: promhttp.Handler()}
+	s.mu.Unlock()
 
 	return s.http.ListenAndServe()
 }
 
 // Stop prometheus metrics service.
 func (s *Service) Stop() {
-	// gracefully stop server
-	go s.http.Shutdown(context.Background())
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.http != nil {
+		// gracefully stop server
+		go s.http.Shutdown(context.Background())
+	}
 }