google.golang.org/grpc@v1.74.2/xds/internal/xdsclient/client.go (about)

     1  /*
     2   *
     3   * Copyright 2019 gRPC authors.
     4   *
     5   * Licensed under the Apache License, Version 2.0 (the "License");
     6   * you may not use this file except in compliance with the License.
     7   * You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   */
    18  
    19  // Package xdsclient implements a full fledged gRPC client for the xDS API used
    20  // by the xds resolver and balancer implementations.
    21  package xdsclient
    22  
    23  import (
    24  	"context"
    25  
    26  	v3statuspb "github.com/envoyproxy/go-control-plane/envoy/service/status/v3"
    27  	"google.golang.org/grpc/internal/xds/bootstrap"
    28  	"google.golang.org/grpc/xds/internal/clients/lrsclient"
    29  	"google.golang.org/grpc/xds/internal/xdsclient/xdsresource"
    30  )
    31  
    32  // XDSClient is a full fledged gRPC client which queries a set of discovery APIs
    33  // (collectively termed as xDS) on a remote management server, to discover
    34  // various dynamic resources.
    35  type XDSClient interface {
    36  	// WatchResource uses xDS to discover the resource associated with the
    37  	// provided resource name. The resource type implementation determines how
    38  	// xDS responses are are deserialized and validated, as received from the
    39  	// xDS management server. Upon receipt of a response from the management
    40  	// server, an appropriate callback on the watcher is invoked.
    41  	//
    42  	// Most callers will not have a need to use this API directly. They will
    43  	// instead use a resource-type-specific wrapper API provided by the relevant
    44  	// resource type implementation.
    45  	//
    46  	//
    47  	// During a race (e.g. an xDS response is received while the user is calling
    48  	// cancel()), there's a small window where the callback can be called after
    49  	// the watcher is canceled. Callers need to handle this case.
    50  	WatchResource(rType xdsresource.Type, resourceName string, watcher xdsresource.ResourceWatcher) (cancel func())
    51  
    52  	ReportLoad(*bootstrap.ServerConfig) (*lrsclient.LoadStore, func(context.Context))
    53  
    54  	BootstrapConfig() *bootstrap.Config
    55  }
    56  
    57  // DumpResources returns the status and contents of all xDS resources. It uses
    58  // xDS clients from the default pool.
    59  func DumpResources() *v3statuspb.ClientStatusResponse {
    60  	return DefaultPool.DumpResources()
    61  }