package xdsdepmgr

import "google.golang.org/grpc/internal/xds/xdsdepmgr"

Package xdsdepmgr provides the implementation of the xDS dependency manager that manages all the xDS watches and resources as described in gRFC A74.

Index ¶

• func SetXDSClusterSubscriber(state resolver.State, subs ClusterSubscriber) resolver.State
• type ClusterSubscriber
• func XDSClusterSubscriberFromResolverState(state resolver.State) ClusterSubscriber
• type ConfigWatcher
• type DependencyManager
• func New(listenerName, dataplaneAuthority string, xdsClient xdsclient.XDSClient, watcher ConfigWatcher) *DependencyManager
• func (m *DependencyManager) Close()
• func (m *DependencyManager) RequestDNSReresolution(opt resolver.ResolveNowOptions)
• func (m *DependencyManager) SubscribeToCluster(name string) func()

Functions ¶

func SetXDSClusterSubscriber ¶

func SetXDSClusterSubscriber(state resolver.State, subs ClusterSubscriber) resolver.State

SetXDSClusterSubscriber returns a copy of state in which the Attributes field is updated with the ClusterSubscriber interface.

Types ¶

type ClusterSubscriber ¶

type ClusterSubscriber interface {
	// SubscribeToCluster creates a dynamic subscription for the named cluster.
	//
	// The returned cancel function must be called when the subscription is no
	// longer needed. It is safe to call cancel multiple times.
	SubscribeToCluster(clusterName string) (cancel func())
}

ClusterSubscriber allows dynamic subscription to clusters. This is useful for scenarios where the cluster name was not present in the RouteConfiguration, e.g. when the route uses a ClusterSpecifierPlugin.

The xDS resolver will pass this interface to the LB policies as an attribute in the resolver update.

func XDSClusterSubscriberFromResolverState ¶

func XDSClusterSubscriberFromResolverState(state resolver.State) ClusterSubscriber

XDSClusterSubscriberFromResolverState returns ClusterSubscriber interface stored as an attribute in the resolver state.

type ConfigWatcher ¶

type ConfigWatcher interface {
	// Update is invoked when a new, validated xDS configuration is available.
	//
	// Implementations must treat the received config as read-only and should
	// not modify it.
	Update(*xdsresource.XDSConfig)

	// Error is invoked when an error is received from the listener or route
	// resource watcher. This includes cases where:
	//  - The listener or route resource watcher reports a resource error.
	//  - The received listener resource is a socket listener, not an API
	//    listener. TODO(i/8114): Implement this check.
	//  - The received route configuration does not contain a virtual host
	//    matching the channel's default authority.
	Error(error)
}

ConfigWatcher is the interface for consumers of aggregated xDS configuration from the DependencyManager. The only consumer of this configuration is currently the xDS resolver.

type DependencyManager ¶

type DependencyManager struct {
	// contains filtered or unexported fields
}

DependencyManager registers watches on the xDS client for all required xDS resources, resolves dependencies between them, and returns a complete configuration to the xDS resolver.

func New ¶

func New(listenerName, dataplaneAuthority string, xdsClient xdsclient.XDSClient, watcher ConfigWatcher) *DependencyManager

New creates a new DependencyManager.

• listenerName is the name of the Listener resource to request from the management server.
• dataplaneAuthority is used to select the best matching virtual host from the route configuration received from the management server.
• xdsClient is the xDS client to use to register resource watches.
• watcher is the ConfigWatcher interface that will receive the aggregated XDSConfig updates and errors.

func (*DependencyManager) Close ¶

func (m *DependencyManager) Close()

Close cancels all registered resource watches.

func (*DependencyManager) RequestDNSReresolution ¶

func (m *DependencyManager) RequestDNSReresolution(opt resolver.ResolveNowOptions)

RequestDNSReresolution calls all the DNS resolver's ResolveNow.

func (*DependencyManager) SubscribeToCluster ¶

func (m *DependencyManager) SubscribeToCluster(name string) func()

SubscribeToCluster increments the reference count for the cluster. If the cluster is not already being tracked, it is added to the clusterSubscriptions map. It returns a function to unsubscribe from the cluster i.e. decrease its refcount. This returned function is idempotent, meaning it can be called multiple times without any additional effect. Calling Subscribe in a blocking manner while handling an update will lead to a deadlock.

Source Files ¶

xds_dependency_manager.go