package api import ( "context" "net/http" "sync" "git.frostfs.info/TrueCloudLab/frostfs-observability/tracing" "github.com/gorilla/mux" "go.opentelemetry.io/otel/attribute" semconv "go.opentelemetry.io/otel/semconv/v1.18.0" "go.opentelemetry.io/otel/trace" ) // TracingMiddleware adds tracing support for requests. func TracingMiddleware() mux.MiddlewareFunc { return func(h http.Handler) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { appCtx, span := StartHTTPServerSpan(r, "REQUEST S3") lw := &traceResponseWriter{ResponseWriter: w, ctx: appCtx, span: span} h.ServeHTTP(lw, r.WithContext(appCtx)) }) } } type traceResponseWriter struct { sync.Once http.ResponseWriter ctx context.Context span trace.Span } func (lrw *traceResponseWriter) WriteHeader(code int) { lrw.Do(func() { lrw.span.SetAttributes( semconv.HTTPStatusCode(code), ) carrier := &httpResponseCarrier{resp: lrw.ResponseWriter} tracing.Propagator.Inject(lrw.ctx, carrier) lrw.ResponseWriter.WriteHeader(code) lrw.span.End() }) } func (lrw *traceResponseWriter) Flush() { if f, ok := lrw.ResponseWriter.(http.Flusher); ok { f.Flush() } } type httpResponseCarrier struct { resp http.ResponseWriter } func (h httpResponseCarrier) Get(key string) string { return h.resp.Header().Get(key) } func (h httpResponseCarrier) Set(key string, value string) { h.resp.Header().Set(key, value) } func (h httpResponseCarrier) Keys() []string { result := make([]string, 0, len(h.resp.Header())) for key := range h.resp.Header() { result = append(result, key) } return result } type httpRequestCarrier struct { req *http.Request } func (c *httpRequestCarrier) Get(key string) string { bytes := c.req.Header.Get(key) if len(bytes) == 0 { return "" } return bytes } func (c *httpRequestCarrier) Set(key string, value string) { c.req.Response.Header.Set(key, value) } func (c *httpRequestCarrier) Keys() []string { result := make([]string, 0, len(c.req.Header)) for key := range c.req.Header { result = append(result, key) } return result } func extractHTTPTraceInfo(ctx context.Context, req *http.Request) context.Context { if req == nil { return ctx } carrier := &httpRequestCarrier{req: req} return tracing.Propagator.Extract(ctx, carrier) } // StartHTTPServerSpan starts root HTTP server span. func StartHTTPServerSpan(r *http.Request, operationName string, opts ...trace.SpanStartOption) (context.Context, trace.Span) { ctx := extractHTTPTraceInfo(r.Context(), r) opts = append(opts, trace.WithAttributes( attribute.String("s3.client_address", r.RemoteAddr), attribute.String("s3.path", r.Host), semconv.HTTPMethod(r.Method), semconv.RPCService("frostfs-s3-gw"), attribute.String("s3.query", r.RequestURI), ), trace.WithSpanKind(trace.SpanKindServer)) return tracing.StartSpanFromContext(ctx, operationName, opts...) }