example_test.go

// Copyright (c) 2017 Uber Technologies, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package config_test

import (
	"log"
	"os"

	opentracing "github.com/opentracing/opentracing-go"
	"github.com/uber/jaeger-lib/metrics"

	"github.com/uber/jaeger-client-go"
	jaegercfg "github.com/uber/jaeger-client-go/config"
	jaegerlog "github.com/uber/jaeger-client-go/log"
)

func ExampleConfiguration_InitGlobalTracer_testing() {
	// Sample configuration for testing. Use constant sampling to sample every trace
	// and enable LogSpan to log every span via configured Logger.
	cfg := jaegercfg.Configuration{
		Sampler: &jaegercfg.SamplerConfig{
			Type:  jaeger.SamplerTypeConst,
			Param: 1,
		},
		Reporter: &jaegercfg.ReporterConfig{
			LogSpans: true,
		},
	}

	// Example logger and metrics factory. Use github.com/uber/jaeger-client-go/log
	// and github.com/uber/jaeger-lib/metrics respectively to bind to real logging and metrics
	// frameworks.
	jLogger := jaegerlog.StdLogger
	jMetricsFactory := metrics.NullFactory

	// Initialize tracer with a logger and a metrics factory
	closer, err := cfg.InitGlobalTracer(
		"serviceName",
		jaegercfg.Logger(jLogger),
		jaegercfg.Metrics(jMetricsFactory),
	)
	if err != nil {
		log.Printf("Could not initialize jaeger tracer: %s", err.Error())
		return
	}
	defer closer.Close()

	// continue main()
}

func ExampleConfiguration_InitGlobalTracer_production() {
	// Recommended configuration for production.
	cfg := jaegercfg.Configuration{}

	// Example logger and metrics factory. Use github.com/uber/jaeger-client-go/log
	// and github.com/uber/jaeger-lib/metrics respectively to bind to real logging and metrics
	// frameworks.
	jLogger := jaegerlog.StdLogger
	jMetricsFactory := metrics.NullFactory

	// Initialize tracer with a logger and a metrics factory
	closer, err := cfg.InitGlobalTracer(
		"serviceName",
		jaegercfg.Logger(jLogger),
		jaegercfg.Metrics(jMetricsFactory),
	)
	if err != nil {
		log.Printf("Could not initialize jaeger tracer: %s", err.Error())
		return
	}
	defer closer.Close()

	// continue main()
}

func ExampleFromEnv() {
	cfg, err := jaegercfg.FromEnv()
	if err != nil {
		// parsing errors might happen here, such as when we get a string where we expect a number
		log.Printf("Could not parse Jaeger env vars: %s", err.Error())
		return
	}

	tracer, closer, err := cfg.NewTracer()
	if err != nil {
		log.Printf("Could not initialize jaeger tracer: %s", err.Error())
		return
	}
	defer closer.Close()

	opentracing.SetGlobalTracer(tracer)
	// continue main()
}

func ExampleFromEnv_override() {
	os.Setenv("JAEGER_SERVICE_NAME", "not-effective")

	cfg, err := jaegercfg.FromEnv()
	if err != nil {
		// parsing errors might happen here, such as when we get a string where we expect a number
		log.Printf("Could not parse Jaeger env vars: %s", err.Error())
		return
	}

	cfg.ServiceName = "this-will-be-the-service-name"

	tracer, closer, err := cfg.NewTracer()
	if err != nil {
		log.Printf("Could not initialize jaeger tracer: %s", err.Error())
		return
	}
	defer closer.Close()

	opentracing.SetGlobalTracer(tracer)
	// continue main()
}