Add tracer configuration support

[ric-plt/tracelibgo.git] / pkg / tracelibgo / tracing.go

diff --git a/pkg/tracelibgo/tracing.go b/pkg/tracelibgo/tracing.go
index df2f45c..f0a3ea2 100644 (file)
--- a/pkg/tracelibgo/tracing.go
+++ b/pkg/tracelibgo/tracing.go
@@ -19,16 +19,121 @@
 package tracelibgo
 
 import (
+       "fmt"
        "io"
+       "os"
+       "strconv"
+       "strings"
 
        "github.com/opentracing/opentracing-go"
-       "github.com/uber/jaeger-client-go"
+       jaegercfg "github.com/uber/jaeger-client-go/config"
+       jaegerlog "github.com/uber/jaeger-client-go/log"
 )
 
+const tracingEnabledEnv string = "TRACING_ENABLED"
+const jaegerSamplerTypeEnv string = "TRACING_JAEGER_SAMPLER_TYPE"
+const jaegerSamplerParamEnv = "TRACING_JAEGER_SAMPLER_PARAM"
+const jaegerAgentAddrEnv = "TRACING_JAEGER_AGENT_ADDR"
+const jaegerLogLevelEnv = "TRACING_JAEGER_LOG_LEVEL"
+
+type confMaker struct {
+       ServiceName string
+}
+
+type logLevel int
+
+const (
+       logAll  logLevel = iota
+       logErr  logLevel = iota
+       logNone logLevel = iota
+)
+
+func (cm *confMaker) GetEnv(envName string, defval string) (retval string) {
+       retval = os.Getenv(envName)
+       if retval == "" {
+               retval = defval
+       }
+       return
+}
+
+func (cm *confMaker) IsTracingEnabled() bool {
+       val := cm.GetEnv(tracingEnabledEnv, "false")
+       if val == "1" || strings.ToLower(val) == "true" {
+               return true
+       }
+       return false
+}
+
+func createDisabledTracer(name string) (opentracing.Tracer, io.Closer) {
+       if name == "" {
+               name = "dummy"
+       }
+       cfg := jaegercfg.Configuration{
+               ServiceName: name,
+               Disabled:    true,
+       }
+       tracer, closer, err := cfg.NewTracer()
+       if err != nil {
+               fmt.Fprintln(os.Stderr, "tracelibgo: trace creation error: ", err.Error())
+       }
+       return tracer, closer
+}
+
+func (cm *confMaker) getSamplerConfig() jaegercfg.SamplerConfig {
+       samplerType := cm.GetEnv(jaegerSamplerTypeEnv, "const")
+       param, err := strconv.ParseFloat(cm.GetEnv(jaegerSamplerParamEnv, "0.001"), 64)
+       if err != nil {
+               param = 0
+       }
+       return jaegercfg.SamplerConfig{Type: samplerType, Param: param}
+}
+
+func (cm *confMaker) getReporterConfig() jaegercfg.ReporterConfig {
+       agentHostPort := cm.GetEnv(jaegerAgentAddrEnv, "127.0.0.1:6831")
+       if !strings.Contains(agentHostPort, ":") {
+               agentHostPort += ":6831"
+       }
+       return jaegercfg.ReporterConfig{LogSpans: cm.getLoggingLevel() == logAll, LocalAgentHostPort: agentHostPort}
+}
+
+func (cm *confMaker) getLoggingLevel() logLevel {
+       level := strings.ToLower(cm.GetEnv(jaegerLogLevelEnv, "error"))
+       switch level {
+       case "error":
+               return logErr
+       case "all":
+               return logAll
+       default:
+               return logNone
+       }
+}
+
 // CreateTracer creates a tracer entry
 func CreateTracer(name string) (opentracing.Tracer, io.Closer) {
-       tracer, closer := jaeger.NewTracer(name,
-               jaeger.NewConstSampler(false),
-               jaeger.NewNullReporter())
+
+       cm := confMaker{name}
+       if !cm.IsTracingEnabled() {
+               return createDisabledTracer(name)
+       }
+       sampler := cm.getSamplerConfig()
+       reporter := cm.getReporterConfig()
+       cfg := jaegercfg.Configuration{
+               ServiceName: name,
+               Disabled:    false,
+               Sampler:     &sampler,
+               Reporter:    &reporter,
+       }
+       var jaegerLoggerOpt jaegercfg.Option
+       switch cm.getLoggingLevel() {
+       case logAll, logErr:
+               jaegerLoggerOpt = jaegercfg.Logger(jaegerlog.StdLogger)
+       default:
+               jaegerLoggerOpt = jaegercfg.Logger(nil)
+       }
+       tracer, closer, err := cfg.NewTracer(jaegerLoggerOpt)
+       if err != nil {
+               fmt.Fprintln(os.Stderr, "tracelibgo: cannot init tracer: "+err.Error())
+               return createDisabledTracer(name)
+       }
        return tracer, closer
 }