micro: rewrite options to support multiple building blocks

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

register/register.go

@@ -0,0 +1,91 @@
+// Package register is an interface for service discovery
+package register
+
+import (
+	"context"
+	"errors"
+
+	"github.com/unistack-org/micro/v3/metadata"
+)
+
+const (
+	// WildcardDomain indicates any domain
+	WildcardDomain = "*"
+	// DefaultDomain to use if none was provided in options
+	DefaultDomain = "micro"
+)
+
+var (
+	// DefaultRegister is the global default register
+	DefaultRegister Register = NewRegister()
+	// ErrNotFound returned when LookupService is called and no services found
+	ErrNotFound = errors.New("service not found")
+	// ErrWatcherStopped returned when when watcher is stopped
+	ErrWatcherStopped = errors.New("watcher stopped")
+)
+
+// Register provides an interface for service discovery
+// and an abstraction over varying implementations
+// {consul, etcd, zookeeper, ...}
+type Register interface {
+	Name() string
+	Init(...Option) error
+	Options() Options
+	Connect(context.Context) error
+	Disconnect(context.Context) error
+	Register(context.Context, *Service, ...RegisterOption) error
+	Deregister(context.Context, *Service, ...DeregisterOption) error
+	LookupService(context.Context, string, ...LookupOption) ([]*Service, error)
+	ListServices(context.Context, ...ListOption) ([]*Service, error)
+	Watch(context.Context, ...WatchOption) (Watcher, error)
+	String() string
+}
+
+// Service holds service register info
+type Service struct {
+	Name      string            `json:"name"`
+	Version   string            `json:"version"`
+	Metadata  metadata.Metadata `json:"metadata"`
+	Endpoints []*Endpoint       `json:"endpoints"`
+	Nodes     []*Node           `json:"nodes"`
+}
+
+// Node holds node register info
+type Node struct {
+	Id       string            `json:"id"`
+	Address  string            `json:"address"`
+	Metadata metadata.Metadata `json:"metadata"`
+}
+
+// Endpoint holds endpoint register info
+type Endpoint struct {
+	Name     string            `json:"name"`
+	Request  *Value            `json:"request"`
+	Response *Value            `json:"response"`
+	Metadata metadata.Metadata `json:"metadata"`
+}
+
+// Value holds additional kv stuff
+type Value struct {
+	Name   string   `json:"name"`
+	Type   string   `json:"type"`
+	Values []*Value `json:"values"`
+}
+
+// Option func signature
+type Option func(*Options)
+
+// RegisterOption option is used to register service
+type RegisterOption func(*RegisterOptions)
+
+// WatchOption option is used to watch service changes
+type WatchOption func(*WatchOptions)
+
+// DeregisterOption option is used to deregister service
+type DeregisterOption func(*DeregisterOptions)
+
+// LookupOption option is used to get service
+type LookupOption func(*LookupOptions)
+
+// ListOption option is used to list services
+type ListOption func(*ListOptions)