// Package server is an interface for a micro server package server import ( "context" "os" "os/signal" "syscall" "time" "github.com/google/uuid" "github.com/micro/go-micro/codec" "github.com/micro/go-micro/registry" log "github.com/micro/go-micro/util/log" ) // Server is a simple micro server abstraction type Server interface { Options() Options Init(...Option) error Handle(Handler) error NewHandler(interface{}, ...HandlerOption) Handler NewSubscriber(string, interface{}, ...SubscriberOption) Subscriber Subscribe(Subscriber) error Start() error Stop() error String() string } // Router handle serving messages type Router interface { // ProcessMessage processes a message ProcessMessage(context.Context, Message) error // ServeRequest processes a request to completion ServeRequest(context.Context, Request, Response) error } // Message is an async message interface type Message interface { // Topic of the message Topic() string // The decoded payload value Payload() interface{} // The content type of the payload ContentType() string // The raw headers of the message Header() map[string]string // The raw body of the message Body() []byte // Codec used to decode the message Codec() codec.Reader } // Request is a synchronous request interface type Request interface { // Service name requested Service() string // The action requested Method() string // Endpoint name requested Endpoint() string // Content type provided ContentType() string // Header of the request Header() map[string]string // Body is the initial decoded value Body() interface{} // Read the undecoded request body Read() ([]byte, error) // The encoded message stream Codec() codec.Reader // Indicates whether its a stream Stream() bool } // Response is the response writer for unencoded messages type Response interface { // Encoded writer Codec() codec.Writer // Write the header WriteHeader(map[string]string) // write a response directly to the client Write([]byte) error } // Stream 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 indicates end of the stream. type Stream interface { Context() context.Context Request() Request Send(interface{}) error Recv(interface{}) error Error() error Close() error } // Handler interface represents a request handler. It's generated // by passing any type of public concrete object with endpoints into server.NewHandler. // Most will pass in a struct. // // Example: // // type Greeter struct {} // // func (g *Greeter) Hello(context, request, response) error { // return nil // } // type Handler interface { Name() string Handler() interface{} Endpoints() []*registry.Endpoint Options() HandlerOptions } // Subscriber interface represents a subscription to a given topic using // a specific subscriber function or object with endpoints. type Subscriber interface { Topic() string Subscriber() interface{} Endpoints() []*registry.Endpoint Options() SubscriberOptions } type Option func(*Options) var ( DefaultAddress = ":0" DefaultName = "go.micro.server" DefaultVersion = time.Now().Format("2006.01.02.15.04") DefaultId = uuid.New().String() DefaultServer Server = newRpcServer() DefaultRouter = newRpcRouter() DefaultRegisterCheck = func(context.Context) error { return nil } DefaultRegisterInterval = time.Second * 30 DefaultRegisterTTL = time.Minute // NewServer creates a new server NewServer func(...Option) Server = newRpcServer ) // DefaultOptions returns config options for the default service func DefaultOptions() Options { return DefaultServer.Options() } // Init initialises the default server with options passed in func Init(opt ...Option) { if DefaultServer == nil { DefaultServer = newRpcServer(opt...) } DefaultServer.Init(opt...) } // NewRouter returns a new router func NewRouter() *router { return newRpcRouter() } // NewSubscriber 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...) } // NewHandler creates a new handler interface using the default server // Handlers are required to be a public object with public // endpoints. Call to a service endpoint 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...) } // Handle registers a handler interface with the default server to // handle inbound requests func Handle(h Handler) error { return DefaultServer.Handle(h) } // Subscribe 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) } // 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 } ch := make(chan os.Signal, 1) signal.Notify(ch, syscall.SIGTERM, syscall.SIGINT) log.Logf("Received signal %s", <-ch) return Stop() } // Start starts the default server func Start() error { config := DefaultServer.Options() log.Logf("Starting server %s id %s", config.Name, config.Id) return DefaultServer.Start() } // Stop stops the default server func Stop() error { log.Logf("Stopping server") return DefaultServer.Stop() } // String returns name of Server implementation func String() string { return DefaultServer.String() }