maint: update golang/year service to be plain otel (#993)

## Which problem is this PR solving?
Updates the golang year service to use plain otel SDK.

- Closes
#968

## Short description of the changes
- Updates golang year service to use base otel SDK instead of honeycomb
otel distro
- Add missing env vars in tilt file

Tiltfile

@@ -52,6 +52,8 @@ def launch_go_svc(name, dirname="", flags="", auto_init=True):
         'NAME_ENDPOINT': 'http://localhost:8000',
         'YEAR_ENDPOINT': 'http://localhost:6001',
         'MESSAGE_ENDPOINT': 'http://localhost:9000',
+        'OTEL_EXPORTER_OTLP_ENDPOINT': 'api.honeycomb.io:443',
+        'OTEL_EXPORTER_OTLP_HEADERS': 'x-honeycomb-team=' + os.environ['HONEYCOMB_API_KEY']
     }
     if "go" in to_run or name in to_run:
         print("About to start {} with command {}".format(name, cmd))

golang/year-service/main.go

@@ -6,13 +6,17 @@ import (
 	"log"
 	"math/rand"
 	"net/http"
+	"os"
 	"time"
 
 	_ "github.com/honeycombio/honeycomb-opentelemetry-go"
 
-	"github.com/honeycombio/otel-config-go/otelconfig"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/propagation"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 	"go.opentelemetry.io/otel/trace"
 )
 
@@ -41,11 +45,22 @@ func yearHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func main() {
-	otelShutdown, err := otelconfig.ConfigureOpenTelemetry()
-	if err != nil {
-		log.Fatalf("error setting up OTel SDK - %e", err)
-	}
-	defer otelShutdown()
+	ctx := context.Background()
+	exporter, _ := otlptrace.New(ctx, otlptracegrpc.NewClient(
+		otlptracegrpc.WithEndpoint(os.Getenv("OTEL_EXPORTER_OTLP_ENDPOINT")),
+		otlptracegrpc.WithHeaders(map[string]string{
+			"x-honeycomb-team": os.Getenv("HONEYCOMB_API_KEY"),
+		}),
+	))
+	tracerProvider := sdktrace.NewTracerProvider(
+		sdktrace.WithBatcher(exporter),
+	)
+	defer tracerProvider.Shutdown(ctx)
+
+	otel.SetTracerProvider(tracerProvider)
+	otel.SetTextMapPropagator(
+		propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}),
+	)
 
 	tracer = otel.Tracer("greeting-service/year-service")