// transformDecodeError adds additional information when a decode fails. func transformDecodeError(typer runtime.ObjectTyper, baseErr error, into runtime.Object, gvk *unversioned.GroupVersionKind, body []byte) error { objGVKs, _, err := typer.ObjectKinds(into) if err != nil { return err } objGVK := objGVKs[0] if gvk != nil && len(gvk.Kind) > 0 { return errors.NewBadRequest(fmt.Sprintf("%s in version %q cannot be handled as a %s: %v", gvk.Kind, gvk.Version, objGVK.Kind, baseErr)) } summary := summarizeData(body, 30) return errors.NewBadRequest(fmt.Sprintf("the object provided is unrecognized (must be of type %s): %v (%s)", objGVK.Kind, baseErr, summary)) }
// GetResource returns a function that handles retrieving a single resource from a rest.Storage object. func GetResource(r rest.Getter, e rest.Exporter, scope RequestScope) restful.RouteFunction { return getResourceHandler(scope, func(ctx api.Context, name string, req *restful.Request) (runtime.Object, error) { // For performance tracking purposes. trace := util.NewTrace("Get " + req.Request.URL.Path) defer trace.LogIfLong(250 * time.Millisecond) // check for export if values := req.Request.URL.Query(); len(values) > 0 { // TODO: this is internal version, not unversioned exports := unversioned.ExportOptions{} if err := scope.ParameterCodec.DecodeParameters(values, unversioned.GroupVersion{Version: "v1"}, &exports); err != nil { return nil, err } if exports.Export { if e == nil { return nil, errors.NewBadRequest(fmt.Sprintf("export of %q is not supported", scope.Resource.Resource)) } return e.Export(ctx, name, exports) } } return r.Get(ctx, name) }) }
// BeforeUpdate ensures that common operations for all resources are performed on update. It only returns // errors that can be converted to api.Status. It will invoke update validation with the provided existing // and updated objects. func BeforeUpdate(strategy RESTUpdateStrategy, ctx api.Context, obj, old runtime.Object) error { objectMeta, kind, kerr := objectMetaAndKind(strategy, obj) if kerr != nil { return kerr } if strategy.NamespaceScoped() { if !api.ValidNamespace(ctx, objectMeta) { return errors.NewBadRequest("the namespace of the provided object does not match the namespace sent on the request") } } else { objectMeta.Namespace = api.NamespaceNone } strategy.PrepareForUpdate(obj, old) // Ensure some common fields, like UID, are validated for all resources. errs, err := validateCommonFields(obj, old) if err != nil { return errors.NewInternalError(err) } errs = append(errs, strategy.ValidateUpdate(ctx, obj, old)...) if len(errs) > 0 { return errors.NewInvalid(kind.GroupKind(), objectMeta.Name, errs) } strategy.Canonicalize(obj) return nil }
// checkName checks the provided name against the request func checkName(obj runtime.Object, name, namespace string, namer ScopeNamer) error { if objNamespace, objName, err := namer.ObjectName(obj); err == nil { if err != nil { return err } if objName != name { return errors.NewBadRequest(fmt.Sprintf( "the name of the object (%s) does not match the name on the URL (%s)", objName, name)) } if len(namespace) > 0 { if len(objNamespace) > 0 && objNamespace != namespace { return errors.NewBadRequest(fmt.Sprintf( "the namespace of the object (%s) does not match the namespace on the request (%s)", objNamespace, namespace)) } } } return nil }
// ResourceLocation returns a URL to which one can send traffic for the specified service. func (rs *REST) ResourceLocation(ctx api.Context, id string) (*url.URL, http.RoundTripper, error) { // Allow ID as "svcname", "svcname:port", or "scheme:svcname:port". svcScheme, svcName, portStr, valid := utilnet.SplitSchemeNamePort(id) if !valid { return nil, nil, errors.NewBadRequest(fmt.Sprintf("invalid service request %q", id)) } // If a port *number* was specified, find the corresponding service port name if portNum, err := strconv.ParseInt(portStr, 10, 64); err == nil { svc, err := rs.registry.GetService(ctx, svcName) if err != nil { return nil, nil, err } found := false for _, svcPort := range svc.Spec.Ports { if int64(svcPort.Port) == portNum { // use the declared port's name portStr = svcPort.Name found = true break } } if !found { return nil, nil, errors.NewServiceUnavailable(fmt.Sprintf("no service port %d found for service %q", portNum, svcName)) } } eps, err := rs.endpoints.GetEndpoints(ctx, svcName) if err != nil { return nil, nil, err } if len(eps.Subsets) == 0 { return nil, nil, errors.NewServiceUnavailable(fmt.Sprintf("no endpoints available for service %q", svcName)) } // Pick a random Subset to start searching from. ssSeed := rand.Intn(len(eps.Subsets)) // Find a Subset that has the port. for ssi := 0; ssi < len(eps.Subsets); ssi++ { ss := &eps.Subsets[(ssSeed+ssi)%len(eps.Subsets)] if len(ss.Addresses) == 0 { continue } for i := range ss.Ports { if ss.Ports[i].Name == portStr { // Pick a random address. ip := ss.Addresses[rand.Intn(len(ss.Addresses))].IP port := int(ss.Ports[i].Port) return &url.URL{ Scheme: svcScheme, Host: net.JoinHostPort(ip, strconv.Itoa(port)), }, rs.proxyTransport, nil } } } return nil, nil, errors.NewServiceUnavailable(fmt.Sprintf("no endpoints available for service %q", id)) }
func (r *ScaleREST) Get(ctx api.Context, name string) (runtime.Object, error) { deployment, err := r.registry.GetDeployment(ctx, name) if err != nil { return nil, errors.NewNotFound(extensions.Resource("deployments/scale"), name) } scale, err := scaleFromDeployment(deployment) if err != nil { return nil, errors.NewBadRequest(fmt.Sprintf("%v", err)) } return scale, nil }
func (r *ScaleREST) Update(ctx api.Context, name string, objInfo rest.UpdatedObjectInfo) (runtime.Object, bool, error) { deployment, err := r.registry.GetDeployment(ctx, name) if err != nil { return nil, false, errors.NewNotFound(extensions.Resource("deployments/scale"), name) } oldScale, err := scaleFromDeployment(deployment) if err != nil { return nil, false, err } obj, err := objInfo.UpdatedObject(ctx, oldScale) if err != nil { return nil, false, err } if obj == nil { return nil, false, errors.NewBadRequest(fmt.Sprintf("nil update passed to Scale")) } scale, ok := obj.(*extensions.Scale) if !ok { return nil, false, errors.NewBadRequest(fmt.Sprintf("expected input object type to be Scale, but %T", obj)) } if errs := extvalidation.ValidateScale(scale); len(errs) > 0 { return nil, false, errors.NewInvalid(extensions.Kind("Scale"), name, errs) } deployment.Spec.Replicas = scale.Spec.Replicas deployment.ResourceVersion = scale.ResourceVersion deployment, err = r.registry.UpdateDeployment(ctx, deployment) if err != nil { return nil, false, err } newScale, err := scaleFromDeployment(deployment) if err != nil { return nil, false, errors.NewBadRequest(fmt.Sprintf("%v", err)) } return newScale, false, nil }
func TestGenericHttpResponseChecker(t *testing.T) { responseChecker := NewGenericHttpResponseChecker(api.Resource("pods"), "foo") tests := []struct { resp *http.Response expectError bool expected error name string }{ { resp: &http.Response{ Body: ioutil.NopCloser(bytes.NewBufferString("Success")), StatusCode: http.StatusOK, }, expectError: false, name: "ok", }, { resp: &http.Response{ Body: ioutil.NopCloser(bytes.NewBufferString("Invalid request.")), StatusCode: http.StatusBadRequest, }, expectError: true, expected: errors.NewBadRequest("Invalid request."), name: "bad request", }, { resp: &http.Response{ Body: ioutil.NopCloser(bytes.NewBufferString("Pod does not exist.")), StatusCode: http.StatusInternalServerError, }, expectError: true, expected: errors.NewInternalError(fmt.Errorf("%s", "Pod does not exist.")), name: "internal server error", }, } for _, test := range tests { err := responseChecker.Check(test.resp) if test.expectError && err == nil { t.Error("unexpected non-error") } if !test.expectError && err != nil { t.Errorf("unexpected error: %v", err) } if test.expectError && !reflect.DeepEqual(err, test.expected) { t.Errorf("expected: %s, saw: %s", test.expected, err) } } }
// ResourceLocation returns an URL and transport which one can use to send traffic for the specified node. func ResourceLocation(getter ResourceGetter, connection client.ConnectionInfoGetter, proxyTransport http.RoundTripper, ctx api.Context, id string) (*url.URL, http.RoundTripper, error) { schemeReq, name, portReq, valid := utilnet.SplitSchemeNamePort(id) if !valid { return nil, nil, errors.NewBadRequest(fmt.Sprintf("invalid node request %q", id)) } nodeObj, err := getter.Get(ctx, name) if err != nil { return nil, nil, err } node := nodeObj.(*api.Node) hostIP, err := nodeutil.GetNodeHostIP(node) if err != nil { return nil, nil, err } host := hostIP.String() // We check if we want to get a default Kubelet's transport. It happens if either: // - no port is specified in request (Kubelet's port is default), // - we're using Port stored as a DaemonEndpoint and requested port is a Kubelet's port stored in the DaemonEndpoint, // - there's no information in the API about DaemonEnpoint (legacy cluster) and requested port is equal to ports.KubeletPort (cluster-wide config) kubeletPort := node.Status.DaemonEndpoints.KubeletEndpoint.Port if kubeletPort == 0 { kubeletPort = ports.KubeletPort } if portReq == "" || strconv.Itoa(int(kubeletPort)) == portReq { scheme, port, kubeletTransport, err := connection.GetConnectionInfo(ctx, node.Name) if err != nil { return nil, nil, err } return &url.URL{ Scheme: scheme, Host: net.JoinHostPort( host, strconv.FormatUint(uint64(port), 10), ), }, kubeletTransport, nil } return &url.URL{Scheme: schemeReq, Host: net.JoinHostPort(host, portReq)}, proxyTransport, nil }
// DeleteCollection returns a function that will handle a collection deletion func DeleteCollection(r rest.CollectionDeleter, checkBody bool, scope RequestScope, admit admission.Interface) restful.RouteFunction { return func(req *restful.Request, res *restful.Response) { w := res.ResponseWriter // TODO: we either want to remove timeout or document it (if we document, move timeout out of this function and declare it in api_installer) timeout := parseTimeout(req.Request.URL.Query().Get("timeout")) namespace, err := scope.Namer.Namespace(req) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } ctx := scope.ContextFunc(req) ctx = api.WithNamespace(ctx, namespace) if admit != nil && admit.Handles(admission.Delete) { userInfo, _ := api.UserFrom(ctx) err = admit.Admit(admission.NewAttributesRecord(nil, nil, scope.Kind, namespace, "", scope.Resource, scope.Subresource, admission.Delete, userInfo)) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } } listOptions := api.ListOptions{} if err := scope.ParameterCodec.DecodeParameters(req.Request.URL.Query(), scope.Kind.GroupVersion(), &listOptions); err != nil { scope.err(err, res.ResponseWriter, req.Request) return } // transform fields // TODO: DecodeParametersInto should do this. if listOptions.FieldSelector != nil { fn := func(label, value string) (newLabel, newValue string, err error) { return scope.Convertor.ConvertFieldLabel(scope.Kind.GroupVersion().String(), scope.Kind.Kind, label, value) } if listOptions.FieldSelector, err = listOptions.FieldSelector.Transform(fn); err != nil { // TODO: allow bad request to set field causes based on query parameters err = errors.NewBadRequest(err.Error()) scope.err(err, res.ResponseWriter, req.Request) return } } options := &api.DeleteOptions{} if checkBody { body, err := readBody(req.Request) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } if len(body) > 0 { s, err := negotiateInputSerializer(req.Request, scope.Serializer) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } defaultGVK := scope.Kind.GroupVersion().WithKind("DeleteOptions") obj, _, err := scope.Serializer.DecoderToVersion(s, defaultGVK.GroupVersion()).Decode(body, &defaultGVK, options) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } if obj != options { scope.err(fmt.Errorf("decoded object cannot be converted to DeleteOptions"), res.ResponseWriter, req.Request) return } } } result, err := finishRequest(timeout, func() (runtime.Object, error) { return r.DeleteCollection(ctx, options, &listOptions) }) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } // if the rest.Deleter returns a nil object, fill out a status. Callers may return a valid // object with the response. if result == nil { result = &unversioned.Status{ Status: unversioned.StatusSuccess, Code: http.StatusOK, Details: &unversioned.StatusDetails{ Kind: scope.Kind.Kind, }, } } else { // when a non-status response is returned, set the self link if _, ok := result.(*unversioned.Status); !ok { if _, err := setListSelfLink(result, req, scope.Namer); err != nil { scope.err(err, res.ResponseWriter, req.Request) return } } } writeNegotiated(scope.Serializer, scope.Kind.GroupVersion(), w, req.Request, http.StatusOK, result) } }
// UpdateResource returns a function that will handle a resource update func UpdateResource(r rest.Updater, scope RequestScope, typer runtime.ObjectTyper, admit admission.Interface) restful.RouteFunction { return func(req *restful.Request, res *restful.Response) { // For performance tracking purposes. trace := util.NewTrace("Update " + req.Request.URL.Path) defer trace.LogIfLong(250 * time.Millisecond) w := res.ResponseWriter // TODO: we either want to remove timeout or document it (if we document, move timeout out of this function and declare it in api_installer) timeout := parseTimeout(req.Request.URL.Query().Get("timeout")) namespace, name, err := scope.Namer.Name(req) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } ctx := scope.ContextFunc(req) ctx = api.WithNamespace(ctx, namespace) body, err := readBody(req.Request) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } s, err := negotiateInputSerializer(req.Request, scope.Serializer) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } defaultGVK := scope.Kind original := r.New() trace.Step("About to convert to expected version") obj, gvk, err := scope.Serializer.DecoderToVersion(s, defaultGVK.GroupVersion()).Decode(body, &defaultGVK, original) if err != nil { err = transformDecodeError(typer, err, original, gvk, body) scope.err(err, res.ResponseWriter, req.Request) return } if gvk.GroupVersion() != defaultGVK.GroupVersion() { err = errors.NewBadRequest(fmt.Sprintf("the API version in the data (%s) does not match the expected API version (%s)", gvk.GroupVersion(), defaultGVK.GroupVersion())) scope.err(err, res.ResponseWriter, req.Request) return } trace.Step("Conversion done") if err := checkName(obj, name, namespace, scope.Namer); err != nil { scope.err(err, res.ResponseWriter, req.Request) return } var transformers []rest.TransformFunc if admit != nil && admit.Handles(admission.Update) { transformers = append(transformers, func(ctx api.Context, newObj, oldObj runtime.Object) (runtime.Object, error) { userInfo, _ := api.UserFrom(ctx) return newObj, admit.Admit(admission.NewAttributesRecord(newObj, oldObj, scope.Kind, namespace, name, scope.Resource, scope.Subresource, admission.Update, userInfo)) }) } trace.Step("About to store object in database") wasCreated := false result, err := finishRequest(timeout, func() (runtime.Object, error) { obj, created, err := r.Update(ctx, name, rest.DefaultUpdatedObjectInfo(obj, scope.Copier, transformers...)) wasCreated = created return obj, err }) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } trace.Step("Object stored in database") if err := setSelfLink(result, req, scope.Namer); err != nil { scope.err(err, res.ResponseWriter, req.Request) return } trace.Step("Self-link added") status := http.StatusOK if wasCreated { status = http.StatusCreated } write(status, scope.Kind.GroupVersion(), scope.Serializer, result, w, req.Request) } }
func createHandler(r rest.NamedCreater, scope RequestScope, typer runtime.ObjectTyper, admit admission.Interface, includeName bool) restful.RouteFunction { return func(req *restful.Request, res *restful.Response) { // For performance tracking purposes. trace := util.NewTrace("Create " + req.Request.URL.Path) defer trace.LogIfLong(250 * time.Millisecond) w := res.ResponseWriter // TODO: we either want to remove timeout or document it (if we document, move timeout out of this function and declare it in api_installer) timeout := parseTimeout(req.Request.URL.Query().Get("timeout")) var ( namespace, name string err error ) if includeName { namespace, name, err = scope.Namer.Name(req) } else { namespace, err = scope.Namer.Namespace(req) } if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } ctx := scope.ContextFunc(req) ctx = api.WithNamespace(ctx, namespace) gv := scope.Kind.GroupVersion() s, err := negotiateInputSerializer(req.Request, scope.Serializer) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } decoder := scope.Serializer.DecoderToVersion(s, unversioned.GroupVersion{Group: gv.Group, Version: runtime.APIVersionInternal}) body, err := readBody(req.Request) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } defaultGVK := scope.Kind original := r.New() trace.Step("About to convert to expected version") obj, gvk, err := decoder.Decode(body, &defaultGVK, original) if err != nil { err = transformDecodeError(typer, err, original, gvk, body) scope.err(err, res.ResponseWriter, req.Request) return } if gvk.GroupVersion() != gv { err = errors.NewBadRequest(fmt.Sprintf("the API version in the data (%s) does not match the expected API version (%v)", gvk.GroupVersion().String(), gv.String())) scope.err(err, res.ResponseWriter, req.Request) return } trace.Step("Conversion done") if admit != nil && admit.Handles(admission.Create) { userInfo, _ := api.UserFrom(ctx) err = admit.Admit(admission.NewAttributesRecord(obj, nil, scope.Kind, namespace, name, scope.Resource, scope.Subresource, admission.Create, userInfo)) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } } trace.Step("About to store object in database") result, err := finishRequest(timeout, func() (runtime.Object, error) { out, err := r.Create(ctx, name, obj) if status, ok := out.(*unversioned.Status); ok && err == nil && status.Code == 0 { status.Code = http.StatusCreated } return out, err }) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } trace.Step("Object stored in database") if err := setSelfLink(result, req, scope.Namer); err != nil { scope.err(err, res.ResponseWriter, req.Request) return } trace.Step("Self-link added") write(http.StatusCreated, scope.Kind.GroupVersion(), scope.Serializer, result, w, req.Request) } }
// ListResource returns a function that handles retrieving a list of resources from a rest.Storage object. func ListResource(r rest.Lister, rw rest.Watcher, scope RequestScope, forceWatch bool, minRequestTimeout time.Duration) restful.RouteFunction { return func(req *restful.Request, res *restful.Response) { // For performance tracking purposes. trace := util.NewTrace("List " + req.Request.URL.Path) w := res.ResponseWriter namespace, err := scope.Namer.Namespace(req) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } // Watches for single objects are routed to this function. // Treat a /name parameter the same as a field selector entry. hasName := true _, name, err := scope.Namer.Name(req) if err != nil { hasName = false } ctx := scope.ContextFunc(req) ctx = api.WithNamespace(ctx, namespace) opts := api.ListOptions{} if err := scope.ParameterCodec.DecodeParameters(req.Request.URL.Query(), scope.Kind.GroupVersion(), &opts); err != nil { scope.err(err, res.ResponseWriter, req.Request) return } // transform fields // TODO: DecodeParametersInto should do this. if opts.FieldSelector != nil { fn := func(label, value string) (newLabel, newValue string, err error) { return scope.Convertor.ConvertFieldLabel(scope.Kind.GroupVersion().String(), scope.Kind.Kind, label, value) } if opts.FieldSelector, err = opts.FieldSelector.Transform(fn); err != nil { // TODO: allow bad request to set field causes based on query parameters err = errors.NewBadRequest(err.Error()) scope.err(err, res.ResponseWriter, req.Request) return } } if hasName { // metadata.name is the canonical internal name. // generic.SelectionPredicate will notice that this is // a request for a single object and optimize the // storage query accordingly. nameSelector := fields.OneTermEqualSelector("metadata.name", name) if opts.FieldSelector != nil && !opts.FieldSelector.Empty() { // It doesn't make sense to ask for both a name // and a field selector, since just the name is // sufficient to narrow down the request to a // single object. scope.err(errors.NewBadRequest("both a name and a field selector provided; please provide one or the other."), res.ResponseWriter, req.Request) return } opts.FieldSelector = nameSelector } if (opts.Watch || forceWatch) && rw != nil { watcher, err := rw.Watch(ctx, &opts) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } // TODO: Currently we explicitly ignore ?timeout= and use only ?timeoutSeconds=. timeout := time.Duration(0) if opts.TimeoutSeconds != nil { timeout = time.Duration(*opts.TimeoutSeconds) * time.Second } if timeout == 0 && minRequestTimeout > 0 { timeout = time.Duration(float64(minRequestTimeout) * (rand.Float64() + 1.0)) } serveWatch(watcher, scope, req, res, timeout) return } // Log only long List requests (ignore Watch). defer trace.LogIfLong(500 * time.Millisecond) trace.Step("About to List from storage") result, err := r.List(ctx, &opts) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } trace.Step("Listing from storage done") numberOfItems, err := setListSelfLink(result, req, scope.Namer) if err != nil { scope.err(err, res.ResponseWriter, req.Request) return } trace.Step("Self-linking done") write(http.StatusOK, scope.Kind.GroupVersion(), scope.Serializer, result, w, req.Request) trace.Step(fmt.Sprintf("Writing http response done (%d items)", numberOfItems)) } }
// Serve serves a series of encoded events via HTTP with Transfer-Encoding: chunked // or over a websocket connection. func (s *WatchServer) ServeHTTP(w http.ResponseWriter, req *http.Request) { w = httplog.Unlogged(w) if wsstream.IsWebSocketRequest(req) { w.Header().Set("Content-Type", s.mediaType) websocket.Handler(s.HandleWS).ServeHTTP(w, req) return } cn, ok := w.(http.CloseNotifier) if !ok { err := fmt.Errorf("unable to start watch - can't get http.CloseNotifier: %#v", w) utilruntime.HandleError(err) s.scope.err(errors.NewInternalError(err), w, req) return } flusher, ok := w.(http.Flusher) if !ok { err := fmt.Errorf("unable to start watch - can't get http.Flusher: %#v", w) utilruntime.HandleError(err) s.scope.err(errors.NewInternalError(err), w, req) return } framer := s.framer.NewFrameWriter(w) if framer == nil { // programmer error err := fmt.Errorf("no stream framing support is available for media type %q", s.mediaType) utilruntime.HandleError(err) s.scope.err(errors.NewBadRequest(err.Error()), w, req) return } e := streaming.NewEncoder(framer, s.encoder) // ensure the connection times out timeoutCh, cleanup := s.t.TimeoutCh() defer cleanup() defer s.watching.Stop() // begin the stream w.Header().Set("Content-Type", s.mediaType) w.Header().Set("Transfer-Encoding", "chunked") w.WriteHeader(http.StatusOK) flusher.Flush() var unknown runtime.Unknown internalEvent := &versioned.InternalEvent{} buf := &bytes.Buffer{} ch := s.watching.ResultChan() for { select { case <-cn.CloseNotify(): return case <-timeoutCh: return case event, ok := <-ch: if !ok { // End of results. return } obj := event.Object s.fixup(obj) if err := s.embeddedEncoder.Encode(obj, buf); err != nil { // unexpected error utilruntime.HandleError(fmt.Errorf("unable to encode watch object: %v", err)) return } // ContentType is not required here because we are defaulting to the serializer // type unknown.Raw = buf.Bytes() event.Object = &unknown // the internal event will be versioned by the encoder *internalEvent = versioned.InternalEvent(event) if err := e.Encode(internalEvent); err != nil { utilruntime.HandleError(fmt.Errorf("unable to encode watch object: %v (%#v)", err, e)) // client disconnect. return } if len(ch) == 0 { flusher.Flush() } buf.Reset() } } }