Merge branch '7-logging-which-way-we-go' into 'develop'

Resolve "Logging: Which way we go?"

See merge request cocsn/gosdn!22

database/database.go

 package database
 
 import (
-	"log"
-
+	"code.fbi.h-da.de/cocsn/gosdn/log"
 	"github.com/neo4j/neo4j-go-driver/neo4j"
 )
 
@@ -74,7 +73,7 @@ func (d Database) StoreNodes(json string) {
 
 	logError("failed storing Nodes into database", err)
 
-	log.Printf("successfully added Nodes into database")
+	log.Info("successfully added Nodes into database")
 }
 
 //StoreNodeEdgePoints stores the given node edge points (interfaces)
@@ -101,7 +100,7 @@ func (d Database) StoreNodeEdgePoints(json string) {
 
 	setNodeNodeEdgePointsRelation(session)
 
-	log.Printf("successfully added NodeEdgePoints into database")
+	log.Info("successfully added NodeEdgePoints into database")
 
 }
 
@@ -121,12 +120,12 @@ func setNodeNodeEdgePointsRelation(session neo4j.Session) {
 
 	logError("failed storing NodeNodeEdgePointsRelation into database", err)
 
-	log.Printf("successfully stored NodeNodeEdgePointsRelation into database")
+	log.Info("successfully stored NodeNodeEdgePointsRelation into database")
 }
 
 //logError logs error with custom and error message
 func logError(message string, err error) {
 	if err != nil {
-		log.Fatalf("%v: %v", message, err)
+		log.Info("%v: %v", message, err)
 	}
 }

log/logger.go

+package log
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"sync"
+	"time"
+)
+
+var logger *Logger
+var once sync.Once
+
+// Logger is a wrapper for log.Logger and provides
+// methods to enable and disable logging.
+type Logger struct {
+	Out      io.Writer
+	Loglevel Level
+	lock     sync.Mutex
+}
+
+func get() *Logger {
+	once.Do(func() {
+		logger = &Logger{
+			Out:      os.Stdout,
+			Loglevel: INFO,
+			lock:     sync.Mutex{},
+		}
+	})
+	return logger
+}
+
+func Loglevel(level Level) {
+	l := get()
+	l.lock.Lock()
+	defer l.lock.Unlock()
+	l.Loglevel = level
+}
+
+func Output(out io.Writer) {
+	l := get()
+	l.lock.Lock()
+	defer l.lock.Unlock()
+	l.Out = out
+}
+
+func Debug(args ...interface{}) {
+	log(DEBUG, args)
+}
+
+func Info(args ...interface{}) {
+	log(INFO, args)
+}
+
+func Warn(args ...interface{}) {
+	log(WARNING, args)
+}
+
+func Error(args ...interface{}) {
+	log(ERROR, args)
+}
+
+func Fatal(args ...interface{}) {
+	log(FATAL, args)
+}
+
+func Panic(args ...interface{}) {
+	log(PANIC, args)
+}
+
+func log(level Level, args ...interface{}) {
+	l := get()
+	l.lock.Lock()
+	defer l.lock.Unlock()
+	if level <= l.Loglevel {
+		msg := fmt.Sprint(args...)
+		logMessage := time.Now().Format(time.RFC3339) + "\t" + prefix(level) + "\t" + msg + "\n"
+		l.Out.Write([]byte(logMessage))
+	}
+}
+
+func prefix(level Level) string {
+	switch level {
+	case PANIC:
+		return "PANIC"
+	case FATAL:
+		return "FATAL"
+	case ERROR:
+		return "ERROR"
+	case WARNING:
+		return "WARNING"
+	case INFO:
+		return "INFO"
+	case DEBUG:
+		return "DEBUG"
+	}
+	return ""
+}

log/loglevel.go

+package log
+
+type Level uint8
+
+const (
+	PANIC Level = iota
+	FATAL
+	ERROR
+	WARNING
+	INFO
+	DEBUG
+)

main.go

 package main
 
 import (
+	"code.fbi.h-da.de/cocsn/gosdn/log"
 	"code.fbi.h-da.de/cocsn/gosdn/nucleus"
 	"flag"
 )
@@ -15,8 +16,10 @@ func main() {
 	flag.Parse()
 	cliSocket := *cliListenAddr + ":" + *cliListenPort
 
+	log.Loglevel(log.DEBUG)
 	// hand off to cmd for further processing
 	nucleus.StartUp(cliSocket, *configFileName)
+	log.Info("Startup completed")
 	nucleus.Run()
 
 	// nothing to see here, please move on!

nucleus/controller.go

@@ -2,10 +2,10 @@ package nucleus
 
 import (
 	"code.fbi.h-da.de/cocsn/gosdn/database"
+	"code.fbi.h-da.de/cocsn/gosdn/log"
 	"code.fbi.h-da.de/cocsn/gosdn/nucleus/interfaces"
 	"code.fbi.h-da.de/cocsn/gosdn/restconf/client/ciena"
 	"github.com/BurntSushi/toml"
-	"log"
 	"os"
 )
 

nucleus/nucleus-core.go

@@ -3,11 +3,11 @@ package nucleus
 import (
 	pb "code.fbi.h-da.de/cocsn/gosdn/cliInterface"
 	"code.fbi.h-da.de/cocsn/gosdn/database"
+	"code.fbi.h-da.de/cocsn/gosdn/log"
 	"code.fbi.h-da.de/cocsn/gosdn/nucleus/interfaces"
 	"context"
 	_ "github.com/mattn/go-sqlite3"
 	"google.golang.org/grpc"
-	"log"
 	"net"
 	"time"
 )
@@ -20,31 +20,31 @@ type server struct {
 
 // SayHello implements helloworld.GreeterServer
 func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
-	log.Printf("Received: %v", in.GetName())
+	log.Debug("Received: %v", in.GetName())
 	return &pb.HelloReply{Message: "Hello " + in.GetName()}, nil
 }
 
 func (s *server) Shutdown(ctx context.Context, in *pb.ShutdownRequest) (*pb.ShutdownReply, error) {
-	log.Printf("Received: %v", in.GetName())
+	log.Debug("Received: %v", in.GetName())
 	isRunning = false
 	return &pb.ShutdownReply{Message: "Shutdown " + in.GetName()}, nil
 }
 
 func getCLIGoing(core *Core) {
-	log.Println("Starting: GetCLIGoing")
+	log.Info("Starting: GetCLIGoing")
 	// Boot-up the control interface for the cli
 	cliControlListener, err := net.Listen("tcp", core.config.CliSocket)
 	if err != nil {
-		log.Fatalf("failed to listen: %v", err)
+		log.Fatal("failed to listen: %v", err)
 	}
 
 	cliControlServer := grpc.NewServer()
 
 	pb.RegisterGreeterServer(cliControlServer, &server{core: core})
 	if err := cliControlServer.Serve(cliControlListener); err != nil {
-		log.Fatalf("failed to serve: %v", err)
+		log.Fatal("failed to serve: %v", err)
 	}
-	log.Println("Started: GetCLIGoing")
+	log.Info("Started: GetCLIGoing")
 }
 
 /*
@@ -54,8 +54,8 @@ func getCLIGoing(core *Core) {
 // Next-up: backend database.
 
 func StartUp(socket, filename string) {
-	log.Println("This is the network superintendent...")
-	log.Println("Starting my ducks")
+	log.Info("This is the network superintendent...")
+	log.Info("Starting my ducks")
 	// Init the Core
 	core := Core{
 		clients:  make(map[string]interfaces.Client, 0),
@@ -64,7 +64,7 @@ func StartUp(socket, filename string) {
 	core.Init(socket, filename)
 	// Start the GRCP CLI
 	go getCLIGoing(&core)
-	log.Println("and ready for take off")
+	log.Info("and ready for take off")
 
 }
 
@@ -78,8 +78,8 @@ func Run() {
 
 	for isRunning {
 		time.Sleep(10 * time.Second)
-		log.Println("Still alive...")
+		log.Debug("Still alive...")
 	}
 
-	log.Println("Good bye....!")
+	log.Info("Good bye....!")
 }