micro/registry/registry.go
2020-04-14 12:32:59 +01:00

98 lines
2.5 KiB
Go

// Package registry is an interface for service discovery
package registry
import (
"errors"
)
var (
DefaultRegistry = NewRegistry()
// Not found error when GetService is called
ErrNotFound = errors.New("service not found")
// Watcher stopped error when watcher is stopped
ErrWatcherStopped = errors.New("watcher stopped")
)
// The registry provides an interface for service discovery
// and an abstraction over varying implementations
// {consul, etcd, zookeeper, ...}
type Registry interface {
Init(...Option) error
Options() Options
Register(*Service, ...RegisterOption) error
Deregister(*Service, ...DeregisterOption) error
GetService(string, ...GetOption) ([]*Service, error)
ListServices(...ListOption) ([]*Service, error)
Watch(...WatchOption) (Watcher, error)
String() string
}
type Service struct {
Name string `json:"name"`
Version string `json:"version"`
Metadata map[string]string `json:"metadata"`
Endpoints []*Endpoint `json:"endpoints"`
Nodes []*Node `json:"nodes"`
}
type Node struct {
Id string `json:"id"`
Address string `json:"address"`
Metadata map[string]string `json:"metadata"`
}
type Endpoint struct {
Name string `json:"name"`
Request *Value `json:"request"`
Response *Value `json:"response"`
Metadata map[string]string `json:"metadata"`
}
type Value struct {
Name string `json:"name"`
Type string `json:"type"`
Values []*Value `json:"values"`
}
type Option func(*Options)
type RegisterOption func(*RegisterOptions)
type WatchOption func(*WatchOptions)
type DeregisterOption func(*DeregisterOptions)
type GetOption func(*GetOptions)
type ListOption func(*ListOptions)
// Register a service node. Additionally supply options such as TTL.
func Register(s *Service, opts ...RegisterOption) error {
return DefaultRegistry.Register(s, opts...)
}
// Deregister a service node
func Deregister(s *Service) error {
return DefaultRegistry.Deregister(s)
}
// Retrieve a service. A slice is returned since we separate Name/Version.
func GetService(name string) ([]*Service, error) {
return DefaultRegistry.GetService(name)
}
// List the services. Only returns service names
func ListServices() ([]*Service, error) {
return DefaultRegistry.ListServices()
}
// Watch returns a watcher which allows you to track updates to the registry.
func Watch(opts ...WatchOption) (Watcher, error) {
return DefaultRegistry.Watch(opts...)
}
func String() string {
return DefaultRegistry.String()
}