6 files changed, 584 insertions, 0 deletions
diff --git a/service/metrics/config.go b/service/metrics/config.go
new file mode 100644
index 00000000..b9b21ea9
--- /dev/null
+++ b/service/metrics/config.go
@@ -0,0 +1,119 @@
+package metrics
+
+import (
+	"fmt"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/spiral/roadrunner/service"
+)
+
+type Config struct {
+	// Address to listen
+	Address string
+
+	// Collect define application specific metrics.
+	Collect map[string]Collector
+}
+
+// Collector describes single application specific metric.
+type Collector struct {
+	// 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) initCollectors() (map[string]prometheus.Collector, error) {
+	if c.Collect == nil {
+		return nil, nil
+	}
+
+	collectors := make(map[string]prometheus.Collector)
+
+	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 nil, fmt.Errorf("invalid metric type `%s` for `%s`", m.Type, name)
+		}
+
+		if err := prometheus.Register(collector); err != nil {
+			return nil, err
+		}
+
+		collectors[name] = collector
+	}
+
+	return collectors, nil
+}
diff --git a/service/metrics/config_test.go b/service/metrics/config_test.go
new file mode 100644
index 00000000..bd02d1cf
--- /dev/null
+++ b/service/metrics/config_test.go
@@ -0,0 +1,27 @@
+package metrics
+
+import (
+	"encoding/json"
+	"github.com/spiral/roadrunner/service"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+type mockCfg struct{ cfg string }
+
+func (cfg *mockCfg) Get(name string) service.Config  { return nil }
+func (cfg *mockCfg) Unmarshal(out interface{}) error { return json.Unmarshal([]byte(cfg.cfg), out) }
+
+func Test_Config_Hydrate_Error1(t *testing.T) {
+	cfg := &mockCfg{`{"request": {"From": "Something"}}`}
+	c := &Config{}
+
+	assert.NoError(t, c.Hydrate(cfg))
+}
+
+func Test_Config_Hydrate_Error2(t *testing.T) {
+	cfg := &mockCfg{`{"dir": "/dir/"`}
+	c := &Config{}
+
+	assert.Error(t, c.Hydrate(cfg))
+}
diff --git a/service/metrics/rpc.go b/service/metrics/rpc.go
new file mode 100644
index 00000000..30ad6c62
--- /dev/null
+++ b/service/metrics/rpc.go
@@ -0,0 +1,156 @@
+package metrics
+
+import (
+	"fmt"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type rpcServer struct{ svc *Service }
+
+// Metric represent single metric produced by the application.
+type Metric struct {
+	// Collector name.
+	Name string
+
+	// Collector value.
+	Value float64
+
+	// Labels associated with metric. Only for vector metrics.
+	Labels []string
+}
+
+// Add new metric to the designated collector.
+func (rpc *rpcServer) Add(m *Metric, ok *bool) error {
+	c := rpc.svc.Collector(m.Name)
+	if c == nil {
+		return fmt.Errorf("undefined collector `%s`", m.Name)
+	}
+
+	switch c.(type) {
+	case prometheus.Gauge:
+		c.(prometheus.Gauge).Add(m.Value)
+
+	case *prometheus.GaugeVec:
+		if len(m.Labels) == 0 {
+			return fmt.Errorf("required labels for collector `%s`", m.Name)
+		}
+
+		c.(*prometheus.GaugeVec).WithLabelValues(m.Labels...).Add(m.Value)
+
+	case prometheus.Counter:
+		c.(prometheus.Counter).Add(m.Value)
+
+	case *prometheus.CounterVec:
+		if len(m.Labels) == 0 {
+			return fmt.Errorf("required labels for collector `%s`", m.Name)
+		}
+
+		c.(*prometheus.CounterVec).WithLabelValues(m.Labels...).Add(m.Value)
+
+	case prometheus.Summary:
+		c.(prometheus.Counter).Add(m.Value)
+
+	case *prometheus.SummaryVec:
+		if len(m.Labels) == 0 {
+			return fmt.Errorf("required labels for collector `%s`", m.Name)
+		}
+
+		c.(*prometheus.SummaryVec).WithLabelValues(m.Labels...).Observe(m.Value)
+
+	case prometheus.Histogram:
+		c.(prometheus.Histogram).Observe(m.Value)
+
+	case *prometheus.HistogramVec:
+		if len(m.Labels) == 0 {
+			return fmt.Errorf("required labels for collector `%s`", m.Name)
+		}
+
+		c.(*prometheus.HistogramVec).WithLabelValues(m.Labels...).Observe(m.Value)
+	}
+
+	*ok = true
+	return nil
+}
+
+// Sub subtract the value from the specific metric (gauge only).
+func (rpc *rpcServer) Sub(m *Metric, ok *bool) error {
+	c := rpc.svc.Collector(m.Name)
+	if c == nil {
+		return fmt.Errorf("undefined collector `%s`", m.Name)
+	}
+
+	switch c.(type) {
+	case prometheus.Gauge:
+		c.(prometheus.Gauge).Sub(m.Value)
+
+	case *prometheus.GaugeVec:
+		if len(m.Labels) == 0 {
+			return fmt.Errorf("required labels for collector `%s`", m.Name)
+		}
+
+		c.(*prometheus.GaugeVec).WithLabelValues(m.Labels...).Sub(m.Value)
+	default:
+		return fmt.Errorf("collector `%s` does not support method `Sub`", m.Name)
+	}
+
+	*ok = true
+	return nil
+}
+
+// Observe the value (histogram and summary only).
+func (rpc *rpcServer) Observe(m *Metric, ok *bool) error {
+	c := rpc.svc.Collector(m.Name)
+	if c == nil {
+		return fmt.Errorf("undefined collector `%s`", m.Name)
+	}
+
+	switch c.(type) {
+	case *prometheus.SummaryVec:
+		if len(m.Labels) == 0 {
+			return fmt.Errorf("required labels for collector `%s`", m.Name)
+		}
+
+		c.(*prometheus.SummaryVec).WithLabelValues(m.Labels...).Observe(m.Value)
+
+	case prometheus.Histogram:
+		c.(prometheus.Histogram).Observe(m.Value)
+
+	case *prometheus.HistogramVec:
+		if len(m.Labels) == 0 {
+			return fmt.Errorf("required labels for collector `%s`", m.Name)
+		}
+
+		c.(*prometheus.HistogramVec).WithLabelValues(m.Labels...).Observe(m.Value)
+	default:
+		return fmt.Errorf("collector `%s` does not support method `Observe`", m.Name)
+	}
+
+	*ok = true
+	return nil
+}
+
+// Set the metric value (only for gaude).
+func (rpc *rpcServer) Set(m *Metric, ok *bool) error {
+	c := rpc.svc.Collector(m.Name)
+	if c == nil {
+		return fmt.Errorf("undefined collector `%s`", m.Name)
+	}
+
+	switch c.(type) {
+	case prometheus.Gauge:
+		c.(prometheus.Gauge).Set(m.Value)
+
+	case *prometheus.GaugeVec:
+		if len(m.Labels) == 0 {
+			return fmt.Errorf("required labels for collector `%s`", m.Name)
+		}
+
+		c.(*prometheus.GaugeVec).WithLabelValues(m.Labels...).Set(m.Value)
+
+	default:
+		return fmt.Errorf("collector `%s` does not support method `Set`", m.Name)
+	}
+
+	*ok = true
+	return nil
+}
diff --git a/service/metrics/rpc_test.go b/service/metrics/rpc_test.go
new file mode 100644
index 00000000..1abe097a
--- /dev/null
+++ b/service/metrics/rpc_test.go
@@ -0,0 +1 @@
+package metrics
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)
+}
diff --git a/service/metrics/service_test.go b/service/metrics/service_test.go
new file mode 100644
index 00000000..513b3042
--- /dev/null
+++ b/service/metrics/service_test.go
@@ -0,0 +1,190 @@
+package metrics
+
+import (
+	"encoding/json"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/sirupsen/logrus"
+	"github.com/sirupsen/logrus/hooks/test"
+	"github.com/spiral/roadrunner/service"
+	"github.com/stretchr/testify/assert"
+	"io/ioutil"
+	"net/http"
+	"testing"
+	"time"
+)
+
+type testCfg struct {
+	metricsCfg string
+	target     string
+}
+
+func (cfg *testCfg) Get(name string) service.Config {
+	if name == ID {
+		return &testCfg{target: cfg.metricsCfg}
+	}
+
+	return nil
+}
+
+func (cfg *testCfg) Unmarshal(out interface{}) error {
+	err := json.Unmarshal([]byte(cfg.target), out)
+	return err
+}
+
+// get request and return body
+func get(url string) (string, *http.Response, error) {
+	r, err := http.Get(url)
+	if err != nil {
+		return "", nil, err
+	}
+	defer r.Body.Close()
+
+	b, err := ioutil.ReadAll(r.Body)
+	return string(b), r, err
+}
+
+func TestService_Serve(t *testing.T) {
+	logger, _ := test.NewNullLogger()
+	logger.SetLevel(logrus.DebugLevel)
+
+	c := service.NewContainer(logger)
+	c.Register(ID, &Service{})
+
+	assert.NoError(t, c.Init(&testCfg{metricsCfg: `{
+		"address": "localhost:2112"
+	}`}))
+
+	s, _ := c.Get(ID)
+	assert.NotNil(t, s)
+
+	go func() { c.Serve() }()
+	time.Sleep(time.Millisecond * 100)
+	defer c.Stop()
+
+	out, _, err := get("http://localhost:2112/metrics")
+	assert.NoError(t, err)
+
+	assert.Contains(t, out, "go_gc_duration_seconds")
+}
+
+func Test_ServiceCustomMetric(t *testing.T) {
+	logger, _ := test.NewNullLogger()
+	logger.SetLevel(logrus.DebugLevel)
+
+	c := service.NewContainer(logger)
+	c.Register(ID, &Service{})
+
+	assert.NoError(t, c.Init(&testCfg{metricsCfg: `{
+		"address": "localhost:2112"
+	}`}))
+
+	s, _ := c.Get(ID)
+	assert.NotNil(t, s)
+
+	collector := prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "my_gauge",
+		Help: "My gauge value",
+	})
+
+	assert.NoError(t, s.(*Service).Register(collector))
+
+	go func() { c.Serve() }()
+	time.Sleep(time.Millisecond * 100)
+	defer c.Stop()
+
+	collector.Set(100)
+
+	out, _, err := get("http://localhost:2112/metrics")
+	assert.NoError(t, err)
+
+	assert.Contains(t, out, "my_gauge 100")
+}
+
+func Test_ServiceCustomMetricMust(t *testing.T) {
+	logger, _ := test.NewNullLogger()
+	logger.SetLevel(logrus.DebugLevel)
+
+	c := service.NewContainer(logger)
+	c.Register(ID, &Service{})
+
+	assert.NoError(t, c.Init(&testCfg{metricsCfg: `{
+		"address": "localhost:2112"
+	}`}))
+
+	s, _ := c.Get(ID)
+	assert.NotNil(t, s)
+
+	collector := prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "my_gauge_2",
+		Help: "My gauge value",
+	})
+
+	s.(*Service).MustRegister(collector)
+
+	go func() { c.Serve() }()
+	time.Sleep(time.Millisecond * 100)
+	defer c.Stop()
+
+	collector.Set(100)
+
+	out, _, err := get("http://localhost:2112/metrics")
+	assert.NoError(t, err)
+
+	assert.Contains(t, out, "my_gauge_2 100")
+}
+
+func Test_ConfiguredMetric(t *testing.T) {
+	logger, _ := test.NewNullLogger()
+	logger.SetLevel(logrus.DebugLevel)
+
+	c := service.NewContainer(logger)
+	c.Register(ID, &Service{})
+
+	assert.NoError(t, c.Init(&testCfg{metricsCfg: `{
+		"address": "localhost:2112",
+		"collect":{
+			"user_gauge":{
+				"type": "gauge"
+			}
+		}
+
+	}`}))
+
+	s, _ := c.Get(ID)
+	assert.NotNil(t, s)
+
+	assert.True(t, s.(*Service).Enabled())
+
+	go func() { c.Serve() }()
+	time.Sleep(time.Millisecond * 100)
+	defer c.Stop()
+
+	s.(*Service).Collector("user_gauge").(prometheus.Gauge).Set(100)
+
+	assert.Nil(t, s.(*Service).Collector("invalid"))
+
+	out, _, err := get("http://localhost:2112/metrics")
+	assert.NoError(t, err)
+
+	assert.Contains(t, out, "user_gauge 100")
+}
+
+func Test_ConfiguredInvalidMetric(t *testing.T) {
+	logger, _ := test.NewNullLogger()
+	logger.SetLevel(logrus.DebugLevel)
+
+	c := service.NewContainer(logger)
+	c.Register(ID, &Service{})
+
+	assert.NoError(t, c.Init(&testCfg{metricsCfg: `{
+		"address": "localhost:2112",
+		"collect":{
+			"user_gauge":{
+				"type": "invalid"
+			}
+		}
+
+	}`}))
+
+	assert.Error(t, c.Serve())
+}