add metrics for log messages categorized by their level

cmd/bee/cmd/start.go

@@ -50,20 +50,20 @@ func (c *command) initStartCmd() (err error) {
 				return cmd.Help()
 			}
 
-			logger := logging.New(cmd.OutOrStdout()).(*logrus.Logger)
+			var logger logging.Logger
 			switch v := strings.ToLower(c.config.GetString(optionNameVerbosity)); v {
 			case "0", "silent":
-				logger.SetOutput(ioutil.Discard)
+				logger = logging.New(ioutil.Discard, 0)
 			case "1", "error":
-				logger.SetLevel(logrus.ErrorLevel)
+				logger = logging.New(cmd.OutOrStdout(), logrus.ErrorLevel)
 			case "2", "warn":
-				logger.SetLevel(logrus.WarnLevel)
+				logger = logging.New(cmd.OutOrStdout(), logrus.WarnLevel)
 			case "3", "info":
-				logger.SetLevel(logrus.InfoLevel)
+				logger = logging.New(cmd.OutOrStdout(), logrus.InfoLevel)
 			case "4", "debug":
-				logger.SetLevel(logrus.DebugLevel)
+				logger = logging.New(cmd.OutOrStdout(), logrus.DebugLevel)
 			case "5", "trace":
-				logger.SetLevel(logrus.TraceLevel)
+				logger = logging.New(cmd.OutOrStdout(), logrus.TraceLevel)
 			default:
 				return fmt.Errorf("unknown verbosity level %q", v)
 			}

pkg/api/api.go

@@ -8,13 +8,13 @@ import (
 	"net/http"
 
 	"github.com/ethersphere/bee/pkg/logging"
+	m "github.com/ethersphere/bee/pkg/metrics"
 	"github.com/ethersphere/bee/pkg/pingpong"
-	"github.com/prometheus/client_golang/prometheus"
 )
 
 type Service interface {
 	http.Handler
-	Metrics() (cs []prometheus.Collector)
+	m.Collector
 }
 
 type server struct {

pkg/api/api_test.go

@@ -24,7 +24,7 @@ type testServerOptions struct {
 func newTestServer(t *testing.T, o testServerOptions) (client *http.Client, cleanup func()) {
 	s := api.New(api.Options{
 		Pingpong: o.Pingpong,
-		Logger:   logging.New(ioutil.Discard),
+		Logger:   logging.New(ioutil.Discard, 0),
 	})
 	ts := httptest.NewServer(s)
 	cleanup = ts.Close

pkg/debugapi/debugapi.go

@@ -7,8 +7,8 @@ package debugapi
 import (
 	"net/http"
 
-	"github.com/ethersphere/bee/pkg/p2p"
 	"github.com/ethersphere/bee/pkg/logging"
+	"github.com/ethersphere/bee/pkg/p2p"
 	"github.com/prometheus/client_golang/prometheus"
 )
 

pkg/debugapi/debugapi_test.go

@@ -24,7 +24,7 @@ type testServerOptions struct {
 func newTestServer(t *testing.T, o testServerOptions) (client *http.Client, cleanup func()) {
 	s := debugapi.New(debugapi.Options{
 		P2P:    o.P2P,
-		Logger: logging.New(ioutil.Discard),
+		Logger: logging.New(ioutil.Discard, 0),
 	})
 	ts := httptest.NewServer(s)
 	cleanup = ts.Close

pkg/logging/logging.go

@@ -21,17 +21,27 @@ type Logger interface {
 	Warning(args ...interface{})
 	Errorf(format string, args ...interface{})
 	Error(args ...interface{})
-	SetOutput(io.Writer)
-	SetLevel(logrus.Level)
 	WithField(key string, value interface{}) *logrus.Entry
 	WithFields(fields logrus.Fields) *logrus.Entry
+	WriterLevel(logrus.Level) *io.PipeWriter
 }
 
-func New(w io.Writer) Logger {
+type logger struct {
+	*logrus.Logger
+	metrics metrics
+}
+
+func New(w io.Writer, level logrus.Level) Logger {
 	l := logrus.New()
 	l.SetOutput(w)
+	l.SetLevel(level)
 	l.Formatter = &logrus.TextFormatter{
 		FullTimestamp: true,
 	}
-	return l
+	metrics := newMetrics()
+	l.AddHook(metrics)
+	return &logger{
+		Logger:  l,
+		metrics: metrics,
+	}
 }

pkg/logging/metrics.go

+// Copyright 2020 The Swarm Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package logging
+
+import (
+	m "github.com/ethersphere/bee/pkg/metrics"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/sirupsen/logrus"
+)
+
+type metrics struct {
+	// all metrics fields must be exported
+	// to be able to return them by Metrics()
+	// using reflection
+	ErrorCount prometheus.Counter
+	WarnCount  prometheus.Counter
+	InfoCount  prometheus.Counter
+	DebugCount prometheus.Counter
+	TraceCount prometheus.Counter
+}
+
+func newMetrics() (m metrics) {
+	return metrics{
+		ErrorCount: prometheus.NewCounter(prometheus.CounterOpts{
+			Name: "log_error_count",
+			Help: "Number ERROR log messages.",
+		}),
+		WarnCount: prometheus.NewCounter(prometheus.CounterOpts{
+			Name: "log_warn_count",
+			Help: "Number WARN log messages.",
+		}),
+		InfoCount: prometheus.NewCounter(prometheus.CounterOpts{
+			Name: "log_info_count",
+			Help: "Number INFO log messages.",
+		}),
+		DebugCount: prometheus.NewCounter(prometheus.CounterOpts{
+			Name: "log_debug_count",
+			Help: "Number DEBUG log messages.",
+		}),
+		TraceCount: prometheus.NewCounter(prometheus.CounterOpts{
+			Name: "log_trace_count",
+			Help: "Number TRACE log messages.",
+		}),
+	}
+}
+
+func (l *logger) Metrics() []prometheus.Collector {
+	return m.PrometheusCollectorsFromFields(l.metrics)
+}
+
+func (m metrics) Levels() []logrus.Level {
+	return []logrus.Level{
+		logrus.ErrorLevel,
+		logrus.WarnLevel,
+		logrus.InfoLevel,
+		logrus.DebugLevel,
+		logrus.TraceLevel,
+	}
+}
+
+func (m metrics) Fire(e *logrus.Entry) error {
+	switch e.Level {
+	case logrus.ErrorLevel:
+		m.ErrorCount.Inc()
+	case logrus.WarnLevel:
+		m.WarnCount.Inc()
+	case logrus.InfoLevel:
+		m.InfoCount.Inc()
+	case logrus.DebugLevel:
+		m.DebugCount.Inc()
+	case logrus.TraceLevel:
+		m.TraceCount.Inc()
+	}
+	return nil
+}

pkg/metrics/metrics.go

@@ -10,6 +10,10 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 )
 
+type Collector interface {
+	Metrics() []prometheus.Collector
+}
+
 func PrometheusCollectorsFromFields(i interface{}) (cs []prometheus.Collector) {
 	v := reflect.Indirect(reflect.ValueOf(i))
 	for i := 0; i < v.NumField(); i++ {

pkg/node/node.go

@@ -17,6 +17,8 @@ import (
 
 	"github.com/ethersphere/bee/pkg/api"
 	"github.com/ethersphere/bee/pkg/debugapi"
+	"github.com/ethersphere/bee/pkg/logging"
+	"github.com/ethersphere/bee/pkg/metrics"
 	"github.com/ethersphere/bee/pkg/p2p/libp2p"
 	"github.com/ethersphere/bee/pkg/pingpong"
 )
@@ -33,7 +35,7 @@ type Options struct {
 	APIAddr       string
 	DebugAPIAddr  string
 	LibP2POptions libp2p.Options
-	Logger        *logrus.Logger
+	Logger        logging.Logger
 }
 
 func NewBee(o Options) (*Bee, error) {
@@ -113,6 +115,9 @@ func NewBee(o Options) (*Bee, error) {
 		if apiService != nil {
 			debugAPIService.MustRegisterMetrics(apiService.Metrics()...)
 		}
+		if l, ok := logger.(metrics.Collector); ok {
+			debugAPIService.MustRegisterMetrics(l.Metrics()...)
+		}
 
 		debugAPIListener, err := net.Listen("tcp", o.DebugAPIAddr)
 		if err != nil {

pkg/p2p/libp2p/internal/handshake/handshake_test.go

@@ -43,7 +43,7 @@ func (s *StreamMock) Close() error {
 }
 
 func TestHandshake(t *testing.T) {
-	logger := logging.New(ioutil.Discard)
+	logger := logging.New(ioutil.Discard, 0)
 	info := Info{
 		Address:   "node1",
 		NetworkID: 0,
@@ -118,7 +118,7 @@ func TestHandle(t *testing.T) {
 		Light:     false,
 	}
 
-	logger := logging.New(ioutil.Discard)
+	logger := logging.New(ioutil.Discard, 0)
 	handshakeService := New(nodeInfo.Address, nodeInfo.NetworkID, logger)
 
 	t.Run("OK", func(t *testing.T) {

pkg/pingpong/pingpong_test.go

@@ -22,7 +22,7 @@ import (
 )
 
 func TestPing(t *testing.T) {
-	logger := logging.New(ioutil.Discard)
+	logger := logging.New(ioutil.Discard, 0)
 
 	// create a pingpong server that handles the incoming stream
 	server := pingpong.New(pingpong.Options{