server: implement gRPC skeleton

2018-12-10 18:06:56 -05:00
parent 38d61b509c
commit 79efd4b911
3 changed files with 149 additions and 25 deletions
--- a/server/main.go
+++ b/server/main.go
@@ -0,0 +1,124 @@
+package main
+
+import (
+	"database/sql"
+	"errors"
+	"flag"
+	"net"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/gtank/ctxd/rpc"
+	"github.com/sirupsen/logrus"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+)
+
+var (
+	log = logrus.New()
+
+	ErrNoImpl = errors.New("not yet implemented")
+)
+
+func init() {
+	log.SetFormatter(&logrus.TextFormatter{
+		//DisableColors: true,
+		FullTimestamp:          true,
+		DisableLevelTruncation: true,
+	})
+}
+
+type Options struct {
+	bindAddr    string `json:"bind_address,omitempty"`
+	dbPath      string `json:"db_path"`
+	tlsCertPath string `json:"tls_cert_path,omitempty"`
+	tlsKeyPath  string `json:"tls_cert_key,omitempty"`
+	logLevel    uint64 `json:"log_level,omitempty"`
+	logPath     string `json:"log_file,omitempty"`
+}
+
+func main() {
+	opts := &Options{}
+	flag.StringVar(&opts.bindAddr, "bind-addr", "127.0.0.1:9067", "the address to listen on")
+	flag.StringVar(&opts.dbPath, "db-path", "", "the location of a sqlite database file")
+	flag.StringVar(&opts.tlsCertPath, "tls-cert", "", "the path to a TLS certificate (optional)")
+	flag.StringVar(&opts.tlsKeyPath, "tls-key", "", "the path to a TLS key file (optional)")
+	flag.Uint64Var(&opts.logLevel, "log-level", uint64(logrus.InfoLevel), "log level (logrus 1-7)")
+	// TODO prod logging flag.StringVar(&opts.logPath, "log-file", "", "log file to write to")
+	// TODO prod metrics
+	// TODO support config from file
+	flag.Parse()
+
+	if opts.dbPath == "" {
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	log.SetLevel(logrus.Level(opts.logLevel))
+
+	// gRPC initialization
+	var server *grpc.Server
+
+	if opts.tlsCertPath != "" && opts.tlsKeyPath != "" {
+		transportCreds, err := credentials.NewServerTLSFromFile(opts.tlsCertPath, opts.tlsKeyPath)
+		if err != nil {
+			log.WithFields(logrus.Fields{
+				"cert_file": opts.tlsCertPath,
+				"key_path":  opts.tlsKeyPath,
+				"error":     err.Error(),
+			}).Fatal("couldn't load TLS credentials")
+		}
+		server = grpc.NewServer(grpc.Creds(transportCreds))
+	} else {
+		server = grpc.NewServer()
+	}
+
+	// Compact transaction service initialization
+	service, err := NewSQLiteStreamer(opts.dbPath)
+	if err != nil {
+		log.WithFields(logrus.Fields{
+			"db_path": opts.dbPath,
+			"error":   err.Error(),
+		}).Fatal("couldn't create SQL streamer")
+	}
+
+	// Register service
+	rpc.RegisterCompactTxStreamerServer(server, service)
+
+	// Start listening
+	listener, err := net.Listen("tcp", opts.bindAddr)
+	if err != nil {
+		log.WithFields(logrus.Fields{
+			"bind_addr": opts.bindAddr,
+			"error":     err.Error(),
+		}).Fatal("couldn't create listener")
+	}
+
+	// Signal handler for graceful stops
+	signals := make(chan os.Signal, 1)
+	signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM)
+	go func() {
+		s := <-signals
+		log.WithFields(logrus.Fields{
+			"signal": s.String(),
+		}).Info("caught signal, stopping gRPC server")
+		server.GracefulStop()
+	}()
+
+	err = server.Serve(listener)
+	if err != nil {
+		log.WithFields(logrus.Fields{
+			"error": err.Error(),
+		}).Fatal("gRPC server failed")
+	}
+}
+
+// the service type
+type sqlStreamer struct {
+	db *sql.DB
+}
+
+func NewSQLiteStreamer(dbPath string) (rpc.CompactTxStreamerServer, error) {
+	return nil, ErrNoImpl
+}