grpc/service/service.go
2021-09-30 17:11:58 +02:00

316 lines
6.3 KiB
Go

package service
import (
"context"
"crypto/tls"
"fmt"
"net"
"net/http"
"os"
"os/signal"
"reflect"
"strings"
"sync"
"syscall"
"time"
"github.com/fullstorydev/grpchan/inprocgrpc"
"github.com/google/uuid"
grpcmiddleware "github.com/grpc-ecosystem/go-grpc-middleware"
"github.com/jinzhu/gorm"
"github.com/rs/cors"
"github.com/sirupsen/logrus"
"github.com/soheilhy/cmux"
"github.com/spf13/cobra"
"go.uber.org/multierr"
"google.golang.org/grpc"
greflect "google.golang.org/grpc/reflection"
"go.linka.cloud/grpc/registry"
"go.linka.cloud/grpc/registry/noop"
)
type Service interface {
Options() Options
DB() *gorm.DB
Start() error
Stop() error
Close() error
Cmd() *cobra.Command
RegisterService(desc *grpc.ServiceDesc, impl interface{})
}
func New(opts ...Option) (Service, error) {
return newService(opts...)
}
type service struct {
cmd *cobra.Command
opts *options
cancel context.CancelFunc
server *grpc.Server
mu sync.Mutex
running bool
mux *http.ServeMux
// inproc Channel is used to serve grpc gateway
inproc *inprocgrpc.Channel
id string
regSvc *registry.Service
closed chan struct{}
}
func newService(opts ...Option) (*service, error) {
if err := cmd.ParseFlags(os.Args); err != nil {
return nil, err
}
s := &service{
opts: parseFlags(NewOptions()),
cmd: cmd,
id: uuid.New().String(),
mux: http.NewServeMux(),
inproc: &inprocgrpc.Channel{},
}
s.mu.Lock()
defer s.mu.Unlock()
for _, f := range opts {
f(s.opts)
}
if s.opts.error != nil {
return nil, s.opts.error
}
s.opts.ctx, s.cancel = context.WithCancel(s.opts.ctx)
go func() {
for {
select {
case <-s.opts.ctx.Done():
s.Stop()
}
}
}()
if s.opts.registry == nil {
s.opts.registry = noop.New()
}
if err := s.opts.parseTLSConfig(); err != nil {
return nil, err
}
cmd.Use = s.opts.name
cmd.RunE = func(cmd *cobra.Command, args []string) error {
if cmd.Use == "" {
cmd.Use = os.Args[0]
}
return s.run()
}
ui := grpcmiddleware.ChainUnaryServer(s.opts.serverInterceptors...)
s.inproc = s.inproc.WithServerUnaryInterceptor(ui)
si := grpcmiddleware.ChainStreamServer(/*TODO(adphi): add to options*/)
s.inproc = s.inproc.WithServerStreamInterceptor(si)
gopts := []grpc.ServerOption{
grpc.StreamInterceptor(si),
grpc.UnaryInterceptor(ui),
}
s.server = grpc.NewServer(append(gopts, s.opts.serverOpts...)...)
if s.opts.reflection {
greflect.Register(s.server)
}
if err := s.gateway(s.opts.gatewayOpts...); err != nil {
return nil, err
}
// we do not configure grpc web here as the grpc handlers are not yet registered
return s, nil
}
func (s *service) Options() Options {
return s.opts
}
func (s *service) DB() *gorm.DB {
return s.opts.db
}
func (s *service) Cmd() *cobra.Command {
return s.cmd
}
func (s *service) run() error {
s.mu.Lock()
s.closed = make(chan struct{})
// configure grpc web now that we are ready to go
if err := s.grpcWeb(s.opts.grpcWebOpts...); err != nil {
return err
}
lis, err := net.Listen("tcp", s.opts.address)
if err != nil {
return err
}
if s.opts.tlsConfig != nil {
lis = tls.NewListener(lis, s.opts.tlsConfig)
}
s.opts.address = lis.Addr().String()
mux := cmux.New(lis)
mux.SetReadTimeout(5 * time.Second)
gLis := mux.MatchWithWriters(cmux.HTTP2MatchHeaderFieldSendSettings("content-type", "application/grpc"))
hList := mux.Match(cmux.Any())
for i := range s.opts.beforeStart {
if err := s.opts.beforeStart[i](); err != nil {
s.mu.Unlock()
return err
}
}
if err := s.register(); err != nil {
return err
}
s.running = true
errs := make(chan error, 3)
if reflect.DeepEqual(s.opts.cors, cors.Options{}) {
s.opts.cors = cors.Options{
AllowedHeaders: []string{"*"},
AllowedMethods: []string{
http.MethodGet,
http.MethodPost,
http.MethodPut,
http.MethodPatch,
http.MethodDelete,
http.MethodOptions,
http.MethodHead,
},
AllowedOrigins: []string{"*"},
AllowCredentials: true,
}
}
hServer := &http.Server{
Handler: cors.New(s.opts.cors).Handler(s.mux),
}
if s.opts.Gateway() || s.opts.grpcWeb {
go func() {
errs <- hServer.Serve(hList)
hServer.Shutdown(s.opts.ctx)
}()
}
go func() {
errs <- s.server.Serve(gLis)
}()
go func() {
if err := mux.Serve(); err != nil {
// TODO(adphi): find more elegant solution
if ignoreMuxError(err) {
errs <- nil
return
}
errs <- err
return
}
errs <- nil
}()
for i := range s.opts.afterStart {
if err := s.opts.afterStart[i](); err != nil {
s.mu.Unlock()
s.Stop()
return err
}
}
s.mu.Unlock()
sigs := s.notify()
select {
case sig := <-sigs:
fmt.Println()
logrus.Warnf("received %v", sig)
return s.Close()
case err := <-errs:
if err != nil && !ignoreMuxError(err){
logrus.Error(err)
return err
}
return nil
}
}
func (s *service) Start() error {
return s.cmd.Execute()
}
func (s *service) Stop() error {
s.mu.Lock()
defer s.mu.Unlock()
if !s.running {
return nil
}
for i := range s.opts.beforeStop {
if err := s.opts.beforeStop[i](); err != nil {
return err
}
}
if err := s.opts.registry.Deregister(s.regSvc); err != nil {
logrus.Errorf("failed to deregister service: %v", err)
}
defer close(s.closed)
sigs := s.notify()
done := make(chan struct{})
go func() {
logrus.Warn("shutting down gracefully")
s.server.GracefulStop()
close(done)
}()
select {
case sig := <-sigs:
fmt.Println()
logrus.Warnf("received %v", sig)
logrus.Warn("forcing shutdown")
s.server.Stop()
case <-done:
}
s.running = false
s.cancel()
for i := range s.opts.afterStop {
if err := s.opts.afterStop[i](); err != nil {
return err
}
}
logrus.Info("server stopped")
return nil
}
func (s *service) RegisterService(desc *grpc.ServiceDesc, impl interface{}) {
s.server.RegisterService(desc, impl)
s.inproc.RegisterService(desc, impl)
}
func (s *service) Close() error {
err := multierr.Combine(s.Stop())
if s.opts.db != nil {
err = multierr.Append(s.opts.db.Close(), err)
}
<-s.closed
return err
}
func (s *service) notify() <-chan os.Signal {
sigs := make(chan os.Signal, 2)
signal.Notify(sigs, syscall.SIGINT, syscall.SIGQUIT)
return sigs
}
func ignoreMuxError(err error) bool {
if err == nil {
return true
}
return strings.Contains(err.Error(), "use of closed network connection") ||
strings.Contains(err.Error(), "mux: server closed")
}