sd

Documentation

Overview

Package sd defines some interfaces and implementations for service discovery

Index

• Variables
• func RegisterSubscriberFactory(name string, sf SubscriberFactory) error
• type Balancer
  • func NewRandomLB(subscriber Subscriber, seed int64) Balancer
  • func NewRoundRobinLB(subscriber Subscriber) Balancer
• type FixedSubscriber
  • func (s FixedSubscriber) Hosts() ([]string, error)
• type Register
  • func GetRegister() *Register
  • func (r *Register) Get(name string) SubscriberFactory
  • func (r *Register) Register(name string, sf SubscriberFactory) error
• type Subscriber
  • func FixedSubscriberFactory(cfg *config.Backend) Subscriber
  • func GetSubscriber(cfg *config.Backend) Subscriber
• type SubscriberFactory
• type SubscriberFunc
  • func (f SubscriberFunc) Hosts() ([]string, error)

Variables

var ErrNoHosts = errors.New("no hosts available")

ErrNoHosts is the error the balancer must return when there are 0 hosts ready

Functions

func RegisterSubscriberFactory

func RegisterSubscriberFactory(name string, sf SubscriberFactory) error

RegisterSubscriberFactory registers the received factory Deprecated: RegisterSubscriberFactory. Use the GetRegister function

Types

type Balancer

type Balancer interface {
	Host() (string, error)
}

Balancer applys a balancing stategy in order to select the backend host to be used

func NewRandomLB

func NewRandomLB(subscriber Subscriber, seed int64) Balancer

NewRandomLB returns a new balancer using a pseudo-random strategy

func NewRoundRobinLB

func NewRoundRobinLB(subscriber Subscriber) Balancer

NewRoundRobinLB returns a new balancer using a round robin strategy

type FixedSubscriber

type FixedSubscriber []string

FixedSubscriber has a constant set of backend hosts and they never get updated

func (FixedSubscriber) Hosts

func (s FixedSubscriber) Hosts() ([]string, error)

Hosts implements the subscriber interface

type Register

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

Register is a SD register

func GetRegister

func GetRegister() *Register

GetRegister returns the package register

func (*Register) Get

func (r *Register) Get(name string) SubscriberFactory

Get implements the RegisterGetter interface

func (*Register) Register

func (r *Register) Register(name string, sf SubscriberFactory) error

Register implements the RegisterSetter interface

type Subscriber

type Subscriber interface {
	Hosts() ([]string, error)
}

Subscriber keeps the set of backend hosts up to date

func FixedSubscriberFactory

func FixedSubscriberFactory(cfg *config.Backend) Subscriber

FixedSubscriberFactory builds a FixedSubscriber with the received config

func GetSubscriber

func GetSubscriber(cfg *config.Backend) Subscriber

GetSubscriber returns a subscriber from package register Deprecated: GetSubscriber. Use the GetRegister function

type SubscriberFactory

type SubscriberFactory func(*config.Backend) Subscriber

SubscriberFactory builds subscribers with the received config

type SubscriberFunc

type SubscriberFunc func() ([]string, error)

SubscriberFunc type is an adapter to allow the use of ordinary functions as subscribers. If f is a function with the appropriate signature, SubscriberFunc(f) is a Subscriber that calls f.

func (SubscriberFunc) Hosts

func (f SubscriberFunc) Hosts() ([]string, error)

Hosts implements the Subscriber interface by executing the wrapped function