feat(logger,tracing): share OTel resource for logs and traces

Factor the resource detector list into internal/otlpresource so
the logger's OTLP provider and the trace provider describe the
same process with the same attributes.

OTLP log records now carry the full resource (process.pid,
service.name, service.version, host.*, os.*, etc.) instead of
no resource attributes at all.

tracing/tracing.go

@@ -45,19 +45,18 @@ import (
 	"slices"
 	"time"
 
+	"go.ntppool.org/common/internal/otlpresource"
 	"go.ntppool.org/common/internal/tracerconfig"
 	"go.ntppool.org/common/version"
 
 	"go.opentelemetry.io/contrib/exporters/autoexport"
 	"go.opentelemetry.io/otel"
-	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/log/global"
 	"go.opentelemetry.io/otel/propagation"
 	sdklog "go.opentelemetry.io/otel/sdk/log"
 	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/resource"
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
-	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
 	"go.opentelemetry.io/otel/trace"
 )
 
@@ -177,33 +176,15 @@ func SetupSDK(ctx context.Context, cfg *TracerConfig) (shutdown TpShutdownFunc,
 		}
 	}
 
-	resources := []resource.Option{
-		resource.WithFromEnv(),      // Discover and provide attributes from OTEL_RESOURCE_ATTRIBUTES and OTEL_SERVICE_NAME environment variables.
-		resource.WithTelemetrySDK(), // Discover and provide information about the OpenTelemetry SDK used.
-		resource.WithProcess(),      // Discover and provide process information.
-		resource.WithOS(),           // Discover and provide OS information.
-		resource.WithContainer(),    // Discover and provide container information.
-		resource.WithHost(),         // Discover and provide host information.
-
-		// set above via os.Setenv() for WithFromEnv to find
-		// resource.WithAttributes(semconv.ServiceNameKey.String(cfg.ServiceName)),
-
-		resource.WithAttributes(semconv.ServiceVersionKey.String(version.Version())),
-	}
-
-	if len(cfg.Environment) > 0 {
-		resources = append(resources,
-			resource.WithAttributes(attribute.String("environment", cfg.Environment)),
-		)
-	}
-
-	res, err := resource.New(
-		context.Background(),
-		resources...,
-	)
-	if errors.Is(err, resource.ErrPartialResource) || errors.Is(err, resource.ErrSchemaURLConflict) {
-		log.Warn("otel resource setup", "err", err) // Log non-fatal issues.
-	} else if err != nil {
+	// Build the shared OTel resource. Kept in sync between traces, metrics,
+	// and logs via common/internal/otlpresource — update the detector list
+	// there, not here. service.name is supplied via OTEL_SERVICE_NAME (set
+	// above when cfg.ServiceName is provided).
+	res, err := otlpresource.New(ctx, log, otlpresource.Options{
+		ServiceVersion: version.Version(),
+		Environment:    cfg.Environment,
+	})
+	if err != nil {
 		log.Error("otel resource setup", "err", err)
 		return
 	}