1 files changed, 91 insertions, 0 deletions
diff --git a/service/metrics/service.go b/service/metrics/service.go
new file mode 100644
index 00000000..2c94568d
--- /dev/null
+++ b/service/metrics/service.go
@@ -0,0 +1,91 @@
+package metrics
+
+import (
+	"context"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"github.com/spiral/roadrunner/service/rpc"
+	"net/http"
+	"sync"
+)
+
+// ID declares public service name.
+const ID = "metrics"
+
+// Service to manage application metrics using Prometheus.
+type Service struct {
+	cfg        *Config
+	mu         sync.Mutex
+	http       *http.Server
+	collectors sync.Map
+}
+
+// Init service.
+func (s *Service) Init(cfg *Config, r *rpc.Service) (bool, error) {
+	s.cfg = cfg
+
+	if r != nil {
+		if err := r.Register(ID, &rpcServer{s}); err != nil {
+			return false, err
+		}
+	}
+
+	return true, nil
+}
+
+// Enabled indicates that server is able to collect metrics.
+func (s *Service) Enabled() bool {
+	return s.cfg != nil
+}
+
+// Register new prometheus collector.
+func (s *Service) Register(c prometheus.Collector) error {
+	return prometheus.Register(c)
+}
+
+// MustRegister registers new collector or fails with panic.
+func (s *Service) MustRegister(c prometheus.Collector) {
+	if err := prometheus.Register(c); err != nil {
+		panic(err)
+	}
+}
+
+// Serve prometheus metrics service.
+func (s *Service) Serve() error {
+	// register application specific metrics
+	collectors, err := s.cfg.initCollectors()
+	if err != nil {
+		return err
+	}
+
+	for name, collector := range collectors {
+		s.collectors.Store(name, collector)
+	}
+
+	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() {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.http != nil {
+		// gracefully stop server
+		go s.http.Shutdown(context.Background())
+	}
+}
+
+// Collector returns application specific collector by name or nil if collector not found.
+func (s *Service) Collector(name string) prometheus.Collector {
+	collector, ok := s.collectors.Load(name)
+	if !ok {
+		return nil
+	}
+
+	return collector.(prometheus.Collector)
+}