micro/server/rpc_server.go
2019-06-07 15:02:19 +01:00

616 lines
13 KiB
Go

package server
import (
"context"
"fmt"
"runtime/debug"
"sort"
"strconv"
"strings"
"sync"
"time"
"github.com/micro/go-micro/broker"
"github.com/micro/go-micro/codec"
"github.com/micro/go-micro/metadata"
"github.com/micro/go-micro/registry"
"github.com/micro/go-micro/transport"
"github.com/micro/go-micro/util/addr"
log "github.com/micro/go-micro/util/log"
)
type rpcServer struct {
router *router
exit chan chan error
sync.RWMutex
opts Options
handlers map[string]Handler
subscribers map[*subscriber][]broker.Subscriber
// used for first registration
registered bool
// graceful exit
wg *sync.WaitGroup
}
func newRpcServer(opts ...Option) Server {
options := newOptions(opts...)
router := newRpcRouter()
router.hdlrWrappers = options.HdlrWrappers
return &rpcServer{
opts: options,
router: DefaultRouter,
handlers: make(map[string]Handler),
subscribers: make(map[*subscriber][]broker.Subscriber),
exit: make(chan chan error),
wg: wait(options.Context),
}
}
type rpcRouter struct {
h func(context.Context, Request, interface{}) error
}
func (r rpcRouter) ServeRequest(ctx context.Context, req Request, rsp Response) error {
return r.h(ctx, req, rsp)
}
// ServeConn serves a single connection
func (s *rpcServer) ServeConn(sock transport.Socket) {
defer func() {
// close socket
sock.Close()
if r := recover(); r != nil {
log.Log("panic recovered: ", r)
log.Log(string(debug.Stack()))
}
}()
for {
var msg transport.Message
if err := sock.Recv(&msg); err != nil {
return
}
// add to wait group if "wait" is opt-in
if s.wg != nil {
s.wg.Add(1)
}
// we use this Timeout header to set a server deadline
to := msg.Header["Timeout"]
// we use this Content-Type header to identify the codec needed
ct := msg.Header["Content-Type"]
// strip our headers
hdr := make(map[string]string)
for k, v := range msg.Header {
hdr[k] = v
}
// set local/remote ips
hdr["Local"] = sock.Local()
hdr["Remote"] = sock.Remote()
// create new context
ctx := metadata.NewContext(context.Background(), hdr)
// set the timeout if we have it
if len(to) > 0 {
if n, err := strconv.ParseUint(to, 10, 64); err == nil {
ctx, _ = context.WithTimeout(ctx, time.Duration(n))
}
}
// no content type
if len(ct) == 0 {
msg.Header["Content-Type"] = DefaultContentType
ct = DefaultContentType
}
// setup old protocol
cf := setupProtocol(&msg)
// no old codec
if cf == nil {
// TODO: needs better error handling
var err error
if cf, err = s.newCodec(ct); err != nil {
sock.Send(&transport.Message{
Header: map[string]string{
"Content-Type": "text/plain",
},
Body: []byte(err.Error()),
})
if s.wg != nil {
s.wg.Done()
}
return
}
}
rcodec := newRpcCodec(&msg, sock, cf)
// internal request
request := &rpcRequest{
service: getHeader("Micro-Service", msg.Header),
method: getHeader("Micro-Method", msg.Header),
endpoint: getHeader("Micro-Endpoint", msg.Header),
contentType: ct,
codec: rcodec,
header: msg.Header,
body: msg.Body,
socket: sock,
stream: true,
}
// internal response
response := &rpcResponse{
header: make(map[string]string),
socket: sock,
codec: rcodec,
}
// set router
r := Router(s.router)
// if not nil use the router specified
if s.opts.Router != nil {
// create a wrapped function
handler := func(ctx context.Context, req Request, rsp interface{}) error {
return s.opts.Router.ServeRequest(ctx, req, rsp.(Response))
}
// execute the wrapper for it
for i := len(s.opts.HdlrWrappers); i > 0; i-- {
handler = s.opts.HdlrWrappers[i-1](handler)
}
// set the router
r = rpcRouter{handler}
}
// serve the actual request using the request router
if err := r.ServeRequest(ctx, request, response); err != nil {
// write an error response
err = rcodec.Write(&codec.Message{
Header: msg.Header,
Error: err.Error(),
Type: codec.Error,
}, nil)
// could not write the error response
if err != nil {
log.Logf("rpc: unable to write error response: %v", err)
}
if s.wg != nil {
s.wg.Done()
}
return
}
// done
if s.wg != nil {
s.wg.Done()
}
}
}
func (s *rpcServer) newCodec(contentType string) (codec.NewCodec, error) {
if cf, ok := s.opts.Codecs[contentType]; ok {
return cf, nil
}
if cf, ok := DefaultCodecs[contentType]; ok {
return cf, nil
}
return nil, fmt.Errorf("Unsupported Content-Type: %s", contentType)
}
func (s *rpcServer) Options() Options {
s.RLock()
opts := s.opts
s.RUnlock()
return opts
}
func (s *rpcServer) Init(opts ...Option) error {
s.Lock()
for _, opt := range opts {
opt(&s.opts)
}
// update router if its the default
if s.opts.Router == nil {
r := newRpcRouter()
r.hdlrWrappers = s.opts.HdlrWrappers
r.serviceMap = s.router.serviceMap
s.router = r
}
s.Unlock()
return nil
}
func (s *rpcServer) NewHandler(h interface{}, opts ...HandlerOption) Handler {
return s.router.NewHandler(h, opts...)
}
func (s *rpcServer) Handle(h Handler) error {
s.Lock()
defer s.Unlock()
if err := s.router.Handle(h); err != nil {
return err
}
s.handlers[h.Name()] = h
return nil
}
func (s *rpcServer) NewSubscriber(topic string, sb interface{}, opts ...SubscriberOption) Subscriber {
return newSubscriber(topic, sb, opts...)
}
func (s *rpcServer) Subscribe(sb Subscriber) error {
sub, ok := sb.(*subscriber)
if !ok {
return fmt.Errorf("invalid subscriber: expected *subscriber")
}
if len(sub.handlers) == 0 {
return fmt.Errorf("invalid subscriber: no handler functions")
}
if err := validateSubscriber(sb); err != nil {
return err
}
s.Lock()
defer s.Unlock()
_, ok = s.subscribers[sub]
if ok {
return fmt.Errorf("subscriber %v already exists", s)
}
s.subscribers[sub] = nil
return nil
}
func (s *rpcServer) Register() error {
// parse address for host, port
config := s.Options()
var advt, host string
var port int
// check the advertise address first
// if it exists then use it, otherwise
// use the address
if len(config.Advertise) > 0 {
advt = config.Advertise
} else {
advt = config.Address
}
parts := strings.Split(advt, ":")
if len(parts) > 1 {
host = strings.Join(parts[:len(parts)-1], ":")
port, _ = strconv.Atoi(parts[len(parts)-1])
} else {
host = parts[0]
}
addr, err := addr.Extract(host)
if err != nil {
return err
}
// make copy of metadata
md := make(metadata.Metadata)
for k, v := range config.Metadata {
md[k] = v
}
// register service
node := &registry.Node{
Id: config.Name + "-" + config.Id,
Address: addr,
Port: port,
Metadata: md,
}
node.Metadata["transport"] = config.Transport.String()
node.Metadata["broker"] = config.Broker.String()
node.Metadata["server"] = s.String()
node.Metadata["registry"] = config.Registry.String()
node.Metadata["protocol"] = "mucp"
s.RLock()
// Maps are ordered randomly, sort the keys for consistency
var handlerList []string
for n, e := range s.handlers {
// Only advertise non internal handlers
if !e.Options().Internal {
handlerList = append(handlerList, n)
}
}
sort.Strings(handlerList)
var subscriberList []*subscriber
for e := range s.subscribers {
// Only advertise non internal subscribers
if !e.Options().Internal {
subscriberList = append(subscriberList, e)
}
}
sort.Slice(subscriberList, func(i, j int) bool {
return subscriberList[i].topic > subscriberList[j].topic
})
var endpoints []*registry.Endpoint
for _, n := range handlerList {
endpoints = append(endpoints, s.handlers[n].Endpoints()...)
}
for _, e := range subscriberList {
endpoints = append(endpoints, e.Endpoints()...)
}
s.RUnlock()
service := &registry.Service{
Name: config.Name,
Version: config.Version,
Nodes: []*registry.Node{node},
Endpoints: endpoints,
}
s.Lock()
registered := s.registered
s.Unlock()
if !registered {
log.Logf("Registry [%s] Registering node: %s", config.Registry.String(), node.Id)
}
// create registry options
rOpts := []registry.RegisterOption{registry.RegisterTTL(config.RegisterTTL)}
if err := config.Registry.Register(service, rOpts...); err != nil {
return err
}
// already registered? don't need to register subscribers
if registered {
return nil
}
s.Lock()
defer s.Unlock()
s.registered = true
for sb, _ := range s.subscribers {
handler := s.createSubHandler(sb, s.opts)
var opts []broker.SubscribeOption
if queue := sb.Options().Queue; len(queue) > 0 {
opts = append(opts, broker.Queue(queue))
}
if cx := sb.Options().Context; cx != nil {
opts = append(opts, broker.SubscribeContext(cx))
}
if !sb.Options().AutoAck {
opts = append(opts, broker.DisableAutoAck())
}
sub, err := config.Broker.Subscribe(sb.Topic(), handler, opts...)
if err != nil {
return err
}
s.subscribers[sb] = []broker.Subscriber{sub}
}
return nil
}
func (s *rpcServer) Deregister() error {
config := s.Options()
var advt, host string
var port int
// check the advertise address first
// if it exists then use it, otherwise
// use the address
if len(config.Advertise) > 0 {
advt = config.Advertise
} else {
advt = config.Address
}
parts := strings.Split(advt, ":")
if len(parts) > 1 {
host = strings.Join(parts[:len(parts)-1], ":")
port, _ = strconv.Atoi(parts[len(parts)-1])
} else {
host = parts[0]
}
addr, err := addr.Extract(host)
if err != nil {
return err
}
node := &registry.Node{
Id: config.Name + "-" + config.Id,
Address: addr,
Port: port,
}
service := &registry.Service{
Name: config.Name,
Version: config.Version,
Nodes: []*registry.Node{node},
}
log.Logf("Registry [%s] Deregistering node: %s", config.Registry.String(), node.Id)
if err := config.Registry.Deregister(service); err != nil {
return err
}
s.Lock()
if !s.registered {
s.Unlock()
return nil
}
s.registered = false
for sb, subs := range s.subscribers {
for _, sub := range subs {
log.Logf("Unsubscribing from topic: %s", sub.Topic())
sub.Unsubscribe()
}
s.subscribers[sb] = nil
}
s.Unlock()
return nil
}
func (s *rpcServer) Start() error {
registerDebugHandler(s)
config := s.Options()
// start listening on the transport
ts, err := config.Transport.Listen(config.Address)
if err != nil {
return err
}
log.Logf("Transport [%s] Listening on %s", config.Transport.String(), ts.Addr())
// swap address
s.Lock()
addr := s.opts.Address
s.opts.Address = ts.Addr()
s.Unlock()
// connect to the broker
if err := config.Broker.Connect(); err != nil {
return err
}
log.Logf("Broker [%s] Connected to %s", config.Broker.String(), config.Broker.Address())
// use RegisterCheck func before register
if err = s.opts.RegisterCheck(s.opts.Context); err != nil {
log.Logf("Server %s-%s register check error: %s", config.Name, config.Id, err)
} else {
// announce self to the world
if err = s.Register(); err != nil {
log.Logf("Server %s-%s register error: %s", config.Name, config.Id, err)
}
}
exit := make(chan bool)
go func() {
for {
// listen for connections
err := ts.Accept(s.ServeConn)
// TODO: listen for messages
// msg := broker.Exchange(service).Consume()
select {
// check if we're supposed to exit
case <-exit:
return
// check the error and backoff
default:
if err != nil {
log.Logf("Accept error: %v", err)
time.Sleep(time.Second)
continue
}
}
// no error just exit
return
}
}()
go func() {
t := new(time.Ticker)
// only process if it exists
if s.opts.RegisterInterval > time.Duration(0) {
// new ticker
t = time.NewTicker(s.opts.RegisterInterval)
}
// return error chan
var ch chan error
Loop:
for {
select {
// register self on interval
case <-t.C:
s.RLock()
registered := s.registered
s.RUnlock()
if err = s.opts.RegisterCheck(s.opts.Context); err != nil && registered {
log.Logf("Server %s-%s register check error: %s, deregister it", config.Name, config.Id, err)
// deregister self in case of error
if err := s.Deregister(); err != nil {
log.Logf("Server %s-%s deregister error: %s", config.Name, config.Id, err)
}
} else {
if err := s.Register(); err != nil {
log.Logf("Server %s-%s register error: %s", config.Name, config.Id, err)
}
}
// wait for exit
case ch = <-s.exit:
t.Stop()
close(exit)
break Loop
}
}
// deregister self
if err := s.Deregister(); err != nil {
log.Logf("Server %s-%s deregister error: %s", config.Name, config.Id, err)
}
// wait for requests to finish
if s.wg != nil {
s.wg.Wait()
}
// close transport listener
ch <- ts.Close()
// disconnect the broker
config.Broker.Disconnect()
// swap back address
s.Lock()
s.opts.Address = addr
s.Unlock()
}()
return nil
}
func (s *rpcServer) Stop() error {
ch := make(chan error)
s.exit <- ch
return <-ch
}
func (s *rpcServer) String() string {
return "rpc"
}