micro/server/server.go
2016-03-14 11:01:10 +00:00

195 lines
4.4 KiB
Go

/*
Server represents a server instance in go-micro which handles synchronous
requests via handlers and asynchronous requests via subscribers that
register with a broker.
The server combines the all the packages in go-micro to create a whole unit
used for building applications including discovery, client/server communication
and pub/sub.
import "github.com/micro/go-micro/server"
type Greeter struct {}
func (g *Greeter) Hello(ctx context.Context, req *greeter.Request, rsp *greeter.Response) error {
rsp.Msg = "Hello " + req.Name
return nil
}
s := server.NewServer()
s.Handle(
s.NewHandler(&Greeter{}),
)
s.Start()
*/
package server
import (
"log"
"os"
"os/signal"
"syscall"
"github.com/pborman/uuid"
"golang.org/x/net/context"
)
type Server interface {
Options() Options
Init(...Option) error
Handle(Handler) error
NewHandler(interface{}, ...HandlerOption) Handler
NewSubscriber(string, interface{}, ...SubscriberOption) Subscriber
Subscribe(Subscriber) error
Register() error
Deregister() error
Start() error
Stop() error
String() string
}
type Publication interface {
Topic() string
Message() interface{}
ContentType() string
}
type Request interface {
Service() string
Method() string
ContentType() string
Request() interface{}
// indicates whether the request will be streamed
Stream() bool
}
// Streamer represents a stream established with a client.
// A stream can be bidirectional which is indicated by the request.
// The last error will be left in Error().
// EOF indicated end of the stream.
type Streamer interface {
Context() context.Context
Request() Request
Send(interface{}) error
Recv(interface{}) error
Error() error
Close() error
}
type Option func(*Options)
type HandlerOption func(*HandlerOptions)
type SubscriberOption func(*SubscriberOptions)
var (
DefaultAddress = ":0"
DefaultName = "go-server"
DefaultVersion = "1.0.0"
DefaultId = uuid.NewUUID().String()
DefaultServer Server = newRpcServer()
)
// Returns config options for the default service
func DefaultOptions() Options {
return DefaultServer.Options()
}
// Initialises the default server with options passed in
func Init(opt ...Option) {
if DefaultServer == nil {
DefaultServer = newRpcServer(opt...)
}
DefaultServer.Init(opt...)
}
// Returns a new server with options passed in
func NewServer(opt ...Option) Server {
return newRpcServer(opt...)
}
// Creates a new subscriber interface with the given topic
// and handler using the default server
func NewSubscriber(topic string, h interface{}, opts ...SubscriberOption) Subscriber {
return DefaultServer.NewSubscriber(topic, h, opts...)
}
// Creates a new handler interface using the default server
// Handlers are required to be a public object with public
// methods. Call to a service method such as Foo.Bar expects
// the type:
//
// type Foo struct {}
// func (f *Foo) Bar(ctx, req, rsp) error {
// return nil
// }
//
func NewHandler(h interface{}, opts ...HandlerOption) Handler {
return DefaultServer.NewHandler(h, opts...)
}
// Registers a handler interface with the default server to
// handle inbound requests
func Handle(h Handler) error {
return DefaultServer.Handle(h)
}
// Registers a subscriber interface with the default server
// which subscribes to specified topic with the broker
func Subscribe(s Subscriber) error {
return DefaultServer.Subscribe(s)
}
// Registers the default server with the discovery system
func Register() error {
return DefaultServer.Register()
}
// Deregisters the default server from the discovery system
func Deregister() error {
return DefaultServer.Deregister()
}
// Blocking run starts the default server and waits for a kill
// signal before exiting. Also registers/deregisters the server
func Run() error {
if err := Start(); err != nil {
return err
}
if err := DefaultServer.Register(); err != nil {
return err
}
ch := make(chan os.Signal, 1)
signal.Notify(ch, syscall.SIGTERM, syscall.SIGINT, syscall.SIGKILL)
log.Printf("Received signal %s", <-ch)
if err := DefaultServer.Deregister(); err != nil {
return err
}
return Stop()
}
// Starts the default server
func Start() error {
config := DefaultServer.Options()
log.Printf("Starting server %s id %s", config.Name, config.Id)
return DefaultServer.Start()
}
// Stops the default server
func Stop() error {
log.Printf("Stopping server")
return DefaultServer.Stop()
}
func String() string {
return DefaultServer.String()
}