nats

Documentation

Overview

Package nats provide a message broker using NATS.

Index

• Variables
• type Config
  • func ReadConfigFromEnv(opts ...config.ReadOption) Config
• type Nats
  • func New(opts ...Option) *Nats
  • func (n *Nats) Close(ctx context.Context) error
  • func (n *Nats) HealthCheck() health.CheckFunc
  • func (n *Nats) Open(ctx context.Context) error
  • func (n *Nats) Publish(ctx context.Context, topic string, m *broker.Message, ...) error
  • func (n *Nats) Subscribe(ctx context.Context, topic string, h broker.Handler, ...) (broker.Subscriber, error)
• type Option
  • func Address(addrs string) Option
  • func Encoder(encoder broker.Encoder) Option
  • func FromConfig(conf Config) Option
  • func FromEnv(opts ...config.ReadOption) Option
  • func Logger(logger log.Logger) Option
  • func Options(opts ...nats.Option) Option

Variables

var (
	// ErrMissingEncoder report the encoder is missing.
	ErrMissingEncoder = errors.New("nats: missing encoder")
)

Types

type Config

type Config struct {
	Addrs    string        `envconfig:"NATS_ADDRS" default:"nats:4222"`
	Encoder  string        `envconfig:"NATS_ENCODER" default:"protobuf"`
	Timeout  time.Duration `envconfig:"NATS_TIMEOUT" default:"10s"`
	Username string        `envconfig:"NATS_USERNAME"`
	Password string        `envconfig:"NATS_PASSWORD"`
}

Config hold common NATS configurations.

func ReadConfigFromEnv

func ReadConfigFromEnv(opts ...config.ReadOption) Config

ReadConfigFromEnv read NATS configuration from environment variables.

type Nats

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

Nats is an implementation of broker.Broker using NATS.

func New

func New(opts ...Option) *Nats

New return a new NATs message broker. If address is not set, default address "nats:4222" will be used.

func (*Nats) Close

func (n *Nats) Close(ctx context.Context) error

Close flush in-flight messages and close the underlying connection.

func (*Nats) HealthCheck

func (n *Nats) HealthCheck() health.CheckFunc

HealthCheck return a health check func.

func (*Nats) Open

func (n *Nats) Open(ctx context.Context) error

Connect connect to target server.

func (*Nats) Publish

func (n *Nats) Publish(ctx context.Context, topic string, m *broker.Message, opts ...broker.PublishOption) error

Publish implements broker.Broker interface.

func (*Nats) Subscribe

func (n *Nats) Subscribe(ctx context.Context, topic string, h broker.Handler, opts ...broker.SubscribeOption) (broker.Subscriber, error)

Subscribe implements broker.Broker interface.

type Option

type Option func(*Nats)

Option is an optional configuration.

func Address

func Address(addrs string) Option

Address is an option to set target addresses of NATS server. Multiple addresses are separated by comma.

func Encoder

func Encoder(encoder broker.Encoder) Option

Encoder is an option to provide a custom encoder.

func FromConfig

func FromConfig(conf Config) Option

FromConfig is an option to create new broker from an existing config.

func FromEnv

func FromEnv(opts ...config.ReadOption) Option

FromEnv is an option to create new broker base on environment variables.

func Logger

func Logger(logger log.Logger) Option

Logger is an option to provide custom logger.

func Options

func Options(opts ...nats.Option) Option

Options is an option to provide additional nats.Option.