feat: Add package for the default OpenTelemetry usage

go.mod

@@ -11,12 +11,9 @@ require (
 	github.com/go-ozzo/ozzo-validation v3.6.0+incompatible
 	github.com/go-ozzo/ozzo-validation/v4 v4.3.0
 	github.com/golang-jwt/jwt/v4 v4.2.0
-	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/gorilla/websocket v1.4.2
 	github.com/lann/builder v0.0.0-20180802200727-47ae307949d0
 	github.com/lib/pq v1.10.4
-	github.com/onsi/ginkgo v1.7.0 // indirect
-	github.com/onsi/gomega v1.4.3 // indirect
 	github.com/opentracing/opentracing-go v1.2.0
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.11.0
@@ -29,13 +26,28 @@ require (
 	github.com/uber/jaeger-client-go v2.30.0+incompatible
 	github.com/uber/jaeger-lib v2.4.1+incompatible // indirect
 	github.com/urfave/negroni v1.0.0
+	go.opentelemetry.io/contrib/detectors/aws/eks v1.3.0
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.28.0
+	go.opentelemetry.io/contrib/instrumentation/runtime v0.27.0
+	go.opentelemetry.io/contrib/propagators/aws v1.3.0
+	go.opentelemetry.io/contrib/propagators/jaeger v1.3.0
+	go.opentelemetry.io/otel v1.3.0
+	go.opentelemetry.io/otel/exporters/jaeger v1.3.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.3.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.3.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.3.0
+	go.opentelemetry.io/otel/exporters/prometheus v0.26.0
+	go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.3.0
+	go.opentelemetry.io/otel/metric v0.26.0
+	go.opentelemetry.io/otel/sdk v1.3.0
+	go.opentelemetry.io/otel/sdk/export/metric v0.26.0
+	go.opentelemetry.io/otel/sdk/metric v0.26.0
+	go.opentelemetry.io/otel/trace v1.3.0
 	go.uber.org/atomic v1.7.0 // indirect
 	go.uber.org/goleak v1.1.12
-	golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9
+	golang.org/x/crypto v0.0.0-20210220033148-5ea612d1eb83
 	golang.org/x/tools v0.1.8
 	google.golang.org/protobuf v1.27.1
-	gopkg.in/yaml.v2 v2.4.0 // indirect
-	gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776 // indirect
 )
 
 go 1.14

pkg/otel/component/info.go

@@ -0,0 +1,8 @@
+package component
+
+// Info is the component metadata used to configure the OTEL sdks.
+type Info struct {
+	Name    string `json:"name"`
+	Version string `json:"version"`
+	Commit  string `json:"commit"`
+}

pkg/otel/metrics/prom.go

@@ -0,0 +1,87 @@
+package metrics
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/contiamo/go-base/v4/pkg/otel/component"
+	prom "github.com/prometheus/client_golang/prometheus"
+
+	"go.opentelemetry.io/contrib/instrumentation/runtime"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/exporters/prometheus"
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/metric/global"
+	"go.opentelemetry.io/otel/sdk/export/metric/aggregation"
+	controller "go.opentelemetry.io/otel/sdk/metric/controller/basic"
+	processor "go.opentelemetry.io/otel/sdk/metric/processor/basic"
+	selector "go.opentelemetry.io/otel/sdk/metric/selector/simple"
+	"go.opentelemetry.io/otel/sdk/resource"
+	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
+)
+
+// Setup configures the OpenTelemetry Resource and Prometheus metrics exporter.
+// Additionally, it configures and sets the component_info metric that allows
+// you to monitor the version of the application.
+//
+// All metrics are registered with the default Prometheus global registry.
+func Setup(component component.Info) (*prometheus.Exporter, error) {
+	baseResource, err := resource.New(
+		context.Background(),
+		resource.WithHost(),
+		resource.WithAttributes(
+			semconv.ServiceVersionKey.String(component.Version),
+			semconv.ServiceNameKey.String(component.Name),
+		),
+		resource.WithFromEnv(),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	config := prometheus.Config{
+		Registerer: prom.DefaultRegisterer,
+		Gatherer:   prom.DefaultGatherer,
+	}
+	c := controller.New(
+		processor.NewFactory(
+			selector.NewWithHistogramDistribution(),
+			aggregation.CumulativeTemporalitySelector(),
+			processor.WithMemory(true),
+		),
+		controller.WithResource(baseResource),
+	)
+	exporter, err := prometheus.New(config, c)
+	if err != nil {
+		return nil, fmt.Errorf("failed to initialize prometheus exporter: %w", err)
+	}
+	global.SetMeterProvider(exporter.MeterProvider())
+
+	err = runtime.Start(
+		runtime.WithMinimumReadMemStatsInterval(time.Second),
+	)
+	if err != nil {
+		log.Fatalln("failed to start runtime instrumentation:", err)
+	}
+
+	meter := global.Meter(component.Name)
+	componentInfo, err := meter.NewInt64UpDownCounter(
+		"component_info",
+		metric.WithDescription("version information of the component"),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create component_info metric: %w", err)
+	}
+
+	componentInfo.Add(
+		context.Background(),
+		1,
+		attribute.Key("version").String(component.Version),
+		attribute.Key("commit").String(component.Commit),
+		attribute.Key("name").String(component.Name),
+	)
+
+	return exporter, nil
+}

pkg/otel/middleware.go

@@ -0,0 +1,41 @@
+package otel
+
+import (
+	"net/http"
+
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/filters"
+)
+
+// Middleware configures the otelhttp.NewHandler and returns a middleware is compatible
+// with the chi router interface.
+//
+// Example:
+//
+// 	r := chi.NewRouter()
+// 	r.Use(otel.Middleware("Server"))
+//
+// The most common options to pass will be the otelhttp.WithFilter and otelhttp.WithSpanNameFormatter
+//
+// When no options are passed a default filter for /metrics and /health is used.
+func Middleware(name string, opts ...otelhttp.Option) func(next http.Handler) http.Handler {
+	if name == "" {
+		name = "Server"
+	}
+	if len(opts) == 0 {
+		opts = []otelhttp.Option{WithInternalPathFilter}
+	}
+
+	return func(next http.Handler) http.Handler {
+		return otelhttp.NewHandler(next, name, opts...)
+	}
+}
+
+// WithInternalPathFilter is the default tracing filter passed to the Middleware.
+// It filters out /metrics and /health requests.
+var WithInternalPathFilter = otelhttp.WithFilter(
+	filters.None(
+		filters.Path("/metrics"),
+		filters.Path("/health"),
+	),
+)

pkg/otel/tracing/errors.go

@@ -0,0 +1,21 @@
+package tracing
+
+import (
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// RecordError is a utility to simplify recording an error to the
+// OpenTelemetry span and setting the error status code.
+func RecordError(span trace.Span, err error) {
+	if err == nil {
+		return
+	}
+
+	if span == nil {
+		return
+	}
+
+	span.RecordError(err)
+	span.SetStatus(codes.Error, err.Error())
+}