feat: enable tracing (#3528)

internal/telemetry/tracing/google/google_tracer.go

@@ -1,8 +1,7 @@
 package google
 
 import (
-	"os"
-	"strings"
+	"strconv"
 
 	texporter "github.com/GoogleCloudPlatform/opentelemetry-operations-go/exporter/trace"
 	sdk_trace "go.opentelemetry.io/otel/sdk/trace"
@@ -18,15 +17,26 @@ type Config struct {
 	Fraction     float64
 }
 
+func NewTracer(rawConfig map[string]interface{}) (err error) {
+	c := new(Config)
+	c.ProjectID, _ = rawConfig["projectid"].(string)
+	c.MetricPrefix, _ = rawConfig["metricprefix"].(string)
+	fraction, ok := rawConfig["fraction"].(string)
+	if ok {
+		c.Fraction, err = strconv.ParseFloat(fraction, 32)
+		if err != nil {
+			return errors.ThrowInternal(err, "GOOGLE-Dsag3", "could not map fraction")
+		}
+	}
+
+	return c.NewTracer()
+}
+
 type Tracer struct {
 	otel.Tracer
 }
 
 func (c *Config) NewTracer() error {
-	if !envIsSet() {
-		return errors.ThrowInvalidArgument(nil, "GOOGL-sdh3a", "env not properly set, GOOGLE_APPLICATION_CREDENTIALS is misconfigured or missing")
-	}
-
 	sampler := sdk_trace.ParentBased(sdk_trace.TraceIDRatioBased(c.Fraction))
 	exporter, err := texporter.New(texporter.WithProjectID(c.ProjectID))
 	if err != nil {
@@ -37,8 +47,3 @@ func (c *Config) NewTracer() error {
 
 	return nil
 }
-
-func envIsSet() bool {
-	gAuthCred := os.Getenv("GOOGLE_APPLICATION_CREDENTIALS")
-	return strings.Contains(gAuthCred, ".json")
-}