Metrics framework (#926)

Signed-off-by: Cody Littley <[email protected]>

common/metrics/config.go

@@ -0,0 +1,10 @@
+package metrics
+
+// Config provides configuration for a Metrics instance.
+type Config struct {
+	// Namespace is the namespace for the metrics.
+	Namespace string
+
+	// HTTPPort is the port to serve metrics on.
+	HTTPPort int
+}

common/metrics/count_metric.go

@@ -0,0 +1,101 @@
+package metrics
+
+import (
+	"fmt"
+	"github.com/Layr-Labs/eigensdk-go/logging"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var _ CountMetric = &countMetric{}
+
+// countMetric a standard implementation of the CountMetric.
+type countMetric struct {
+	Metric
+
+	// logger is the logger used to log errors.
+	logger logging.Logger
+
+	// name is the name of the metric.
+	name string
+
+	// description is the description of the metric.
+	description string
+
+	// counter is the prometheus counter used to report this metric.
+	vec *prometheus.CounterVec
+
+	// labeler is the label maker used to create labels for this metric.
+	labeler *labelMaker
+}
+
+// newCountMetric creates a new CountMetric instance.
+func newCountMetric(
+	logger logging.Logger,
+	registry *prometheus.Registry,
+	namespace string,
+	name string,
+	description string,
+	labelTemplate any) (CountMetric, error) {
+
+	labeler, err := newLabelMaker(labelTemplate)
+	if err != nil {
+		return nil, err
+	}
+
+	vec := promauto.With(registry).NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: namespace,
+			Name:      fmt.Sprintf("%s_count", name),
+		},
+		labeler.getKeys(),
+	)
+
+	return &countMetric{
+		logger:      logger,
+		name:        name,
+		description: description,
+		vec:         vec,
+		labeler:     labeler,
+	}, nil
+}
+
+func (m *countMetric) Name() string {
+	return m.name
+}
+
+func (m *countMetric) Unit() string {
+	return "count"
+}
+
+func (m *countMetric) Description() string {
+	return m.description
+}
+
+func (m *countMetric) Type() string {
+	return "counter"
+}
+
+func (m *countMetric) LabelFields() []string {
+	return m.labeler.getKeys()
+}
+
+func (m *countMetric) Increment(label ...any) {
+	m.Add(1, label...)
+}
+
+func (m *countMetric) Add(value float64, label ...any) {
+	var l any
+	if len(label) > 0 {
+		l = label[0]
+	}
+
+	values, err := m.labeler.extractValues(l)
+	if err != nil {
+		m.logger.Errorf("error extracting values from label for metric %s: %v", m.name, err)
+		return
+	}
+
+	observer := m.vec.WithLabelValues(values...)
+	observer.Add(value)
+}

common/metrics/gauge_metric.go

@@ -0,0 +1,103 @@
+package metrics
+
+import (
+	"fmt"
+	"github.com/Layr-Labs/eigensdk-go/logging"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var _ GaugeMetric = &gaugeMetric{}
+
+// gaugeMetric is a standard implementation of the GaugeMetric interface via prometheus.
+type gaugeMetric struct {
+	Metric
+
+	// logger is the logger used to log errors.
+	logger logging.Logger
+
+	// name is the name of the metric.
+	name string
+
+	// unit is the unit of the metric.
+	unit string
+
+	// description is the description of the metric.
+	description string
+
+	// gauge is the prometheus gauge used to report this metric.
+	vec *prometheus.GaugeVec
+
+	// labeler is the label maker used to create labels for this metric.
+	labeler *labelMaker
+}
+
+// newGaugeMetric creates a new GaugeMetric instance.
+func newGaugeMetric(
+	logger logging.Logger,
+	registry *prometheus.Registry,
+	namespace string,
+	name string,
+	unit string,
+	description string,
+	labelTemplate any) (GaugeMetric, error) {
+
+	labeler, err := newLabelMaker(labelTemplate)
+	if err != nil {
+		return nil, err
+	}
+
+	vec := promauto.With(registry).NewGaugeVec(
+		prometheus.GaugeOpts{
+			Namespace: namespace,
+			Name:      fmt.Sprintf("%s_%s", name, unit),
+		},
+		labeler.getKeys(),
+	)
+
+	return &gaugeMetric{
+		logger:      logger,
+		name:        name,
+		unit:        unit,
+		description: description,
+		vec:         vec,
+		labeler:     labeler,
+	}, nil
+}
+
+func (m *gaugeMetric) Name() string {
+	return m.name
+}
+
+func (m *gaugeMetric) Unit() string {
+	return m.unit
+}
+
+func (m *gaugeMetric) Description() string {
+	return m.description
+}
+
+func (m *gaugeMetric) Type() string {
+	return "gauge"
+}
+
+func (m *gaugeMetric) LabelFields() []string {
+	return m.labeler.getKeys()
+}
+
+func (m *gaugeMetric) Set(value float64, label ...any) {
+	var l any
+	if len(label) > 0 {
+		l = label[0]
+	}
+
+	values, err := m.labeler.extractValues(l)
+	if err != nil {
+		m.logger.Errorf("failed to extract values from label: %v", err)
+		return
+	}
+
+	observer := m.vec.WithLabelValues(values...)
+
+	observer.Set(value)
+}

common/metrics/label_maker.go

@@ -0,0 +1,73 @@
+package metrics
+
+import (
+	"fmt"
+	"reflect"
+)
+
+// labelMaker encapsulates logic for creating labels for metrics.
+type labelMaker struct {
+	keys         []string
+	emptyValues  []string
+	templateType reflect.Type
+	labelCount   int
+}
+
+// newLabelMaker creates a new labelMaker instance given a label template. The label template may be nil.
+func newLabelMaker(labelTemplate any) (*labelMaker, error) {
+	labeler := &labelMaker{
+		keys: make([]string, 0),
+	}
+
+	if labelTemplate == nil {
+		return labeler, nil
+	}
+
+	v := reflect.ValueOf(labelTemplate)
+	if v.Kind() != reflect.Struct {
+		return nil, fmt.Errorf("label template must be a struct")
+	}
+
+	t := v.Type()
+	labeler.templateType = t
+	for i := 0; i < t.NumField(); i++ {
+
+		fieldType := t.Field(i).Type
+		if fieldType.Kind() != reflect.String {
+			return nil, fmt.Errorf(
+				"field %s has type %v, only string fields are supported", t.Field(i).Name, fieldType)
+		}
+
+		labeler.keys = append(labeler.keys, t.Field(i).Name)
+	}
+
+	labeler.emptyValues = make([]string, len(labeler.keys))
+	labeler.labelCount = len(labeler.keys)
+
+	return labeler, nil
+}
+
+// getKeys provides the keys for the label struct.
+func (l *labelMaker) getKeys() []string {
+	return l.keys
+}
+
+// extractValues extracts the values from the given label struct.
+func (l *labelMaker) extractValues(label any) ([]string, error) {
+	if l.templateType == nil || label == nil {
+		return l.emptyValues, nil
+	}
+
+	if l.templateType != reflect.TypeOf(label) {
+		return nil, fmt.Errorf(
+			"label type mismatch, expected %v, got %v", l.templateType, reflect.TypeOf(label))
+	}
+
+	values := make([]string, 0, l.labelCount)
+	for i := 0; i < l.labelCount; i++ {
+		v := reflect.ValueOf(label)
+		values = append(values, v.Field(i).String())
+	}
+
+	return values, nil
+}

common/metrics/latency_metric.go

@@ -0,0 +1,102 @@
+package metrics
+
+import (
+	"fmt"
+	"github.com/Layr-Labs/eigensdk-go/logging"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	"time"
+)
+
+var _ LatencyMetric = &latencyMetric{}
+
+// latencyMetric is a standard implementation of the LatencyMetric interface via prometheus.
+type latencyMetric struct {
+	Metric
+
+	// logger is the logger used to log errors.
+	logger logging.Logger
+
+	// name is the name of the metric.
+	name string
+
+	// description is the description of the metric.
+	description string
+
+	// vec is the prometheus summary vector used to report this metric.
+	vec *prometheus.SummaryVec
+
+	// lm is the label maker used to create labels for this metric.
+	labeler *labelMaker
+}
+
+// newLatencyMetric creates a new LatencyMetric instance.
+func newLatencyMetric(
+	logger logging.Logger,
+	registry *prometheus.Registry,
+	namespace string,
+	name string,
+	description string,
+	objectives map[float64]float64,
+	labelTemplate any) (LatencyMetric, error) {
+
+	labeler, err := newLabelMaker(labelTemplate)
+	if err != nil {
+		return nil, err
+	}
+
+	vec := promauto.With(registry).NewSummaryVec(
+		prometheus.SummaryOpts{
+			Namespace:  namespace,
+			Name:       fmt.Sprintf("%s_ms", name),
+			Objectives: objectives,
+		},
+		labeler.getKeys(),
+	)
+
+	return &latencyMetric{
+		logger:      logger,
+		name:        name,
+		description: description,
+		vec:         vec,
+		labeler:     labeler,
+	}, nil
+}
+
+func (m *latencyMetric) Name() string {
+	return m.name
+}
+
+func (m *latencyMetric) Unit() string {
+	return "ms"
+}
+
+func (m *latencyMetric) Description() string {
+	return m.description
+}
+
+func (m *latencyMetric) Type() string {
+	return "latency"
+}
+
+func (m *latencyMetric) LabelFields() []string {
+	return m.labeler.getKeys()
+}
+
+func (m *latencyMetric) ReportLatency(latency time.Duration, label ...any) {
+	var l any
+	if len(label) > 0 {
+		l = label[0]
+	}
+
+	values, err := m.labeler.extractValues(l)
+	if err != nil {
+		m.logger.Errorf("error extracting values from label: %v", err)
+	}
+
+	observer := m.vec.WithLabelValues(values...)
+
+	nanoseconds := float64(latency.Nanoseconds())
+	milliseconds := nanoseconds / float64(time.Millisecond)
+	observer.Observe(milliseconds)
+}