/
main.go
96 lines (77 loc) · 2.26 KB
/
main.go
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// Copyright 2017 Alexey Kovrizhkin <lekovr@gmail.com>. All rights reserved.
// Use of this source code is governed by a MIT
// license that can be found in the LICENSE file.
package main
import (
"net"
"os"
"os/signal"
"syscall"
"github.com/jessevdk/go-flags"
"google.golang.org/grpc"
"github.com/LeKovr/metricinc/lib/boltdb"
"github.com/LeKovr/metricinc/lib/grpcapi"
"github.com/LeKovr/metricinc/lib/logger"
pb "github.com/LeKovr/metricinc/lib/proto/counter"
logiface "github.com/LeKovr/metricinc/lib/iface/logger"
)
// Config holds program options
type Config struct {
Listen string `long:"listen" default:":50051" description:"Addr and port which server listens at"`
Logger logger.Config `group:"Logging Options"`
API grpcapi.Config `group:"API Options"`
Store boltdb.Config `group:"Storage Options"`
}
// main - program body
func main() {
// Parse options
var cfg Config
_, err := flags.Parse(&cfg)
if err != nil {
if e, ok := err.(*flags.Error); ok && e.Type == flags.ErrHelp {
os.Exit(1) // help printed
} else {
os.Exit(2) // error message written already
}
}
// Logger
log, err := logger.NewLogger(cfg.Logger)
if err != nil {
panic("Logger init error: " + err.Error())
}
log.Infof("Counter server v%s", Version)
// Listener
log.WithField("addr", cfg.Listen).Debug("Create listener")
lis, err := net.Listen("tcp", cfg.Listen)
stopOnError(log, err, "Listen socket")
// Store
store, err := boltdb.NewStore(log, cfg.Store)
stopOnError(log, err, "DB connect")
// gRPC API
api, err := grpcapi.NewAPI(log, store, cfg.API)
stopOnError(log, err, "Service create")
defer api.Close()
s := grpc.NewServer()
pb.RegisterCounterServer(s, api)
// Gracefull shutdown
// http://stackoverflow.com/questions/18106749/golang-catch-signals
signalChannel := make(chan os.Signal, 2)
signal.Notify(signalChannel, os.Interrupt, syscall.SIGTERM)
go func() {
sig := <-signalChannel
log.Infof("Got signal: %v", sig)
api.Close()
s.GracefulStop()
os.Exit(0)
}()
// Serve
if err := s.Serve(lis); err != nil {
panic("Server init error: " + err.Error())
}
}
// stopOnError used internally for fatal errors checking
func stopOnError(log logiface.Entry, err error, info string) {
if err != nil {
log.Fatalf("Error with %s: %v", info, err)
}
}