naming

Documentation

Overview

Package naming defines the naming API and related data structures for gRPC. The interface is EXPERIMENTAL and may be suject to change.

Index

• type AddrMetadataGRPCLB
• type AddressType
• type Operation
• type Resolver
  • func NewDNSResolver() (Resolver, error)
  • func NewDNSResolverWithFreq(freq time.Duration) (Resolver, error)
• type Update
• type Watcher

Types

type AddrMetadataGRPCLB

type AddrMetadataGRPCLB struct {
	// AddrType is the type of server (grpc load balancer or backend).
	AddrType AddressType
	// ServerName is the name of the grpc load balancer. Used for authentication.
	ServerName string
}

AddrMetadataGRPCLB contains the information the name resolver for grpclb should provide. The name resolver used by the grpclb balancer is required to provide this type of metadata in its address updates.

type AddressType

type AddressType uint8

AddressType indicates the address type returned by name resolution.

const (
	// Backend indicates the server is a backend server.
	Backend AddressType = iota
	// GRPCLB indicates the server is a grpclb load balancer.
	GRPCLB
)

type Operation

type Operation uint8

Operation defines the corresponding operations for a name resolution change.

const (
	// Add indicates a new address is added.
	Add Operation = iota
	// Delete indicates an exisiting address is deleted.
	Delete
)

type Resolver

type Resolver interface {
	// Resolve creates a Watcher for target.
	Resolve(target string) (Watcher, error)
}

Resolver creates a Watcher for a target to track its resolution changes.

func NewDNSResolver

func NewDNSResolver() (Resolver, error)

NewDNSResolver creates a DNS Resolver that can resolve DNS names, and create watchers that poll the DNS server using the default frequency defined by defaultFreq.

func NewDNSResolverWithFreq

func NewDNSResolverWithFreq(freq time.Duration) (Resolver, error)

NewDNSResolverWithFreq creates a DNS Resolver that can resolve DNS names, and create watchers that poll the DNS server using the frequency set by freq.

type Update

type Update struct {
	// Op indicates the operation of the update.
	Op Operation
	// Addr is the updated address. It is empty string if there is no address update.
	Addr string
	// Metadata is the updated metadata. It is nil if there is no metadata update.
	// Metadata is not required for a custom naming implementation.
	Metadata interface{}
}

Update defines a name resolution update. Notice that it is not valid having both empty string Addr and nil Metadata in an Update.

type Watcher

type Watcher interface {
	// Next blocks until an update or error happens. It may return one or more
	// updates. The first call should get the full set of the results. It should
	// return an error if and only if Watcher cannot recover.
	Next() ([]*Update, error)
	// Close closes the Watcher.
	Close()
}

Watcher watches for the updates on the specified target.