add xtel/exporters sub-module

xtel/exporter/doc.go

@@ -0,0 +1,2 @@
+// Package exporter contains basic exporters for xtel like stdout and otlp.
+package exporter

xtel/exporter/example_test.go

@@ -0,0 +1,22 @@
+package exporter_test
+
+import (
+	"fmt"
+
+	"github.com/gojekfarm/xtools/xtel"
+	"github.com/gojekfarm/xtools/xtel/exporter"
+)
+
+func ExampleNewOTLP() {
+	_, err := xtel.NewProvider("eg-service", exporter.NewOTLP(exporter.WithTracesExporterInsecure))
+	if err != nil {
+		fmt.Printf("failed exporting traces to exporter: %s\n", err)
+	}
+}
+
+func ExampleNewSTDOut() {
+	_, err := xtel.NewProvider("eg-service", exporter.NewSTDOut(exporter.STDOutOptions{PrettyPrint: true}))
+	if err != nil {
+		fmt.Printf("failed printing traces to terminal: %s\n", err)
+	}
+}

xtel/exporter/go.mod

@@ -0,0 +1,41 @@
+module github.com/gojekfarm/xtools/xtel/exporter
+
+go 1.19
+
+require (
+	github.com/gojekfarm/xtools/xtel v0.0.0-20230911104033-e5e7b07b8c02
+	github.com/stretchr/testify v1.8.4
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.16.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.16.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.16.0
+	go.opentelemetry.io/otel/exporters/stdout/stdouttrace v1.17.0
+	go.opentelemetry.io/otel/sdk v1.17.0
+)
+
+require (
+	github.com/cenkalti/backoff/v4 v4.2.1 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/felixge/httpsnoop v1.0.3 // indirect
+	github.com/go-logr/logr v1.2.4 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
+	github.com/hashicorp/errwrap v1.0.0 // indirect
+	github.com/hashicorp/go-multierror v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.43.0 // indirect
+	go.opentelemetry.io/otel v1.17.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.16.0 // indirect
+	go.opentelemetry.io/otel/metric v1.17.0 // indirect
+	go.opentelemetry.io/otel/trace v1.17.0 // indirect
+	go.opentelemetry.io/proto/otlp v0.19.0 // indirect
+	golang.org/x/net v0.15.0 // indirect
+	golang.org/x/sys v0.12.0 // indirect
+	golang.org/x/text v0.13.0 // indirect
+	google.golang.org/genproto v0.0.0-20230306155012-7f2fa6fef1f4 // indirect
+	google.golang.org/grpc v1.55.0 // indirect
+	google.golang.org/protobuf v1.30.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
+
+replace github.com/gojekfarm/xtools/xtel => ../

xtel/exporter/options.go

@@ -0,0 +1,57 @@
+package exporter
+
+import (
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
+)
+
+// Option defines the implementation of the configurations.
+type Option interface{ apply(*config) }
+
+const defaultExporterEndpoint = "127.0.0.1:4317"
+
+type config struct {
+	mode                           Mode
+	exporterEndpoint               string
+	tracesExporterEndpointInsecure bool
+	headers                        map[string]string
+}
+
+func newConfig(opts ...Option) *config {
+	c := &config{
+		headers:          make(map[string]string),
+		exporterEndpoint: defaultExporterEndpoint,
+	}
+
+	for _, opt := range opts {
+		opt.apply(c)
+	}
+
+	return c
+}
+
+func (c *config) grpcOptions() []otlptracegrpc.Option {
+	res := []otlptracegrpc.Option{
+		otlptracegrpc.WithEndpoint(c.exporterEndpoint),
+		otlptracegrpc.WithHeaders(c.headers),
+	}
+
+	if c.tracesExporterEndpointInsecure {
+		res = append(res, otlptracegrpc.WithInsecure())
+	}
+
+	return res
+}
+
+func (c *config) httpOptions() []otlptracehttp.Option {
+	res := []otlptracehttp.Option{
+		otlptracehttp.WithEndpoint(c.exporterEndpoint),
+		otlptracehttp.WithHeaders(c.headers),
+	}
+
+	if c.tracesExporterEndpointInsecure {
+		res = append(res, otlptracehttp.WithInsecure())
+	}
+
+	return res
+}

xtel/exporter/otlp.go

@@ -0,0 +1,66 @@
+package exporter
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
+	"go.opentelemetry.io/otel/sdk/trace"
+
+	"github.com/gojekfarm/xtools/xtel"
+)
+
+// Mode is the used to control the export configuration of the otlptrace package exporters.
+type Mode int
+
+const (
+	// GRPC is the default exporters configurations for the Exporter.
+	GRPC Mode = iota
+	// HTTP can set as the configuration for the Exporter.
+	HTTP
+)
+
+// WithTracesExporterEndpoint configures the endpoint for sending traces via OTLP.
+func WithTracesExporterEndpoint(url string) Option {
+	return optionFunc(func(c *config) { c.exporterEndpoint = url })
+}
+
+// WithTracesExporterInsecure permits connecting to the
+// trace endpoint without a certificate.
+var WithTracesExporterInsecure = &insecure{}
+
+// NewOTLP returns a new exporter and starts it. It configs the new exporter with the given Options.
+func NewOTLP(opts ...Option) xtel.ProviderOption {
+	return xtel.WithExporter(func() (trace.SpanExporter, error) {
+		cfg := newConfig(opts...)
+
+		var client otlptrace.Client
+		switch cfg.mode {
+		case GRPC:
+			client = otlptracegrpc.NewClient(cfg.grpcOptions()...)
+		case HTTP:
+			client = otlptracehttp.NewClient(cfg.httpOptions()...)
+		}
+
+		traceExporter, err := newTraceExporter(context.Background(), client)
+		if err != nil {
+			return nil, err
+		}
+
+		return traceExporter, nil
+	})
+}
+
+var newTraceExporter = otlptrace.New
+
+func (m Mode) apply(c *config) { c.mode = m }
+
+type insecure struct {
+}
+
+func (i *insecure) apply(c *config) { c.tracesExporterEndpointInsecure = true }
+
+type optionFunc func(*config)
+
+func (f optionFunc) apply(c *config) { f(c) }

xtel/exporter/otlp_test.go

@@ -0,0 +1,73 @@
+package exporter
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
+
+	"github.com/gojekfarm/xtools/xtel"
+)
+
+func TestNewOTLP(t *testing.T) {
+	tests := []struct {
+		name   string
+		option []Option
+	}{
+		{
+			name:   "Default",
+			option: []Option{WithTracesExporterInsecure},
+		},
+		{
+			name:   "HTTP",
+			option: []Option{HTTP, WithTracesExporterInsecure},
+		},
+		{
+			name:   "Without Insecure Transport Credentials",
+			option: []Option{HTTP},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			p, err := xtel.NewProvider("test", NewOTLP(tc.option...))
+			assert.NoError(t, err)
+			assert.NotNil(t, p)
+		})
+	}
+}
+
+func TestDefaultConfig(t *testing.T) {
+	cfg := newConfig()
+	expected := &config{exporterEndpoint: defaultExporterEndpoint, headers: map[string]string{}}
+
+	assert.Equal(t, expected, cfg)
+}
+
+func TestNewTraceExporter(t *testing.T) {
+	newTraceExporter = func(ctx context.Context, client otlptrace.Client) (*otlptrace.Exporter, error) {
+		return nil, errors.New("context already closed")
+	}
+	defer func() { newTraceExporter = otlptrace.New }()
+
+	p, err := xtel.NewProvider("test-service", NewOTLP())
+	assert.Error(t, err)
+	assert.Nil(t, p)
+}
+
+func TestConfigurationOverrides(t *testing.T) {
+	conf := newConfig(
+		WithTracesExporterEndpoint("override-satellite-url"),
+		WithTracesExporterInsecure,
+	)
+	emptyconfig := newConfig()
+	assert.NotNil(t, emptyconfig)
+	expected := &config{
+		exporterEndpoint:               "override-satellite-url",
+		tracesExporterEndpointInsecure: true,
+		headers:                        map[string]string{},
+	}
+	assert.Equal(t, expected, conf)
+}

xtel/exporter/stdout.go

@@ -0,0 +1,28 @@
+package exporter
+
+import (
+	"os"
+
+	"go.opentelemetry.io/otel/exporters/stdout/stdouttrace"
+	"go.opentelemetry.io/otel/sdk/trace"
+
+	"github.com/gojekfarm/xtools/xtel"
+)
+
+// STDOutOptions handles the configuration of STDOUT output. It handles the PrettyPrint parameter of the application.
+type STDOutOptions struct {
+	PrettyPrint bool
+}
+
+// NewSTDOut exports and writes exported tracing telemetry information in JSON for the given STDOutOptions.
+func NewSTDOut(opts STDOutOptions) xtel.ProviderOption {
+	return xtel.WithExporter(func() (trace.SpanExporter, error) {
+		o := []stdouttrace.Option{stdouttrace.WithWriter(os.Stdout)}
+
+		if opts.PrettyPrint {
+			o = append(o, stdouttrace.WithPrettyPrint())
+		}
+
+		return stdouttrace.New(o...)
+	})
+}

xtel/exporter/stdout_test.go

@@ -0,0 +1,15 @@
+package exporter
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/gojekfarm/xtools/xtel"
+)
+
+func TestNewSTDOut(t *testing.T) {
+	p, err := xtel.NewProvider("test-service", NewSTDOut(STDOutOptions{PrettyPrint: true}))
+	assert.NoError(t, err)
+	assert.NotNil(t, p)
+}