chore: ignore traces from (*API).workspaceAgentCoordinate after accept (#4178)

coderd/tracing/util.go

@@ -1,10 +1,20 @@
 package tracing
 
 import (
+	"context"
 	"runtime"
 	"strings"
+
+	"go.opentelemetry.io/otel/trace"
 )
 
+var NoopSpan trace.Span
+
+func init() {
+	tracer := trace.NewNoopTracerProvider().Tracer("")
+	_, NoopSpan = tracer.Start(context.Background(), "")
+}
+
 const TracerName = "coderd"
 
 func FuncName() string {

coderd/workspaceagents.go

@@ -364,8 +364,11 @@ func (api *API) workspaceAgentCoordinate(rw http.ResponseWriter, r *http.Request
 		return
 	}
 
-	// end span so we don't get long lived trace data
+	// End span so we don't get long lived trace data.
 	tracing.EndHTTPSpan(r, http.StatusOK, trace.SpanFromContext(ctx))
+	// Ignore all trace spans after this.
+	ctx = trace.ContextWithSpan(ctx, tracing.NoopSpan)
+
 	api.Logger.Info(ctx, "accepting agent", slog.F("resource", resource), slog.F("agent", workspaceAgent))
 
 	defer conn.Close(websocket.StatusNormalClosure, "")