log prefix moved to logger

Author: ssgreg

app.go

@@ -103,7 +103,7 @@ func (a *App) Shutdown() {
 	// Wait for all servers to start serving to avoid race conditions
 	// connected with shutdown. 'Shutdown' must be called only if server
 	// has already started or it does nothing.
-	logger.Printf("ZeroDT: shutdown servers...")
+	logger.Printf("shutdown servers...")
 	a.served.Wait()
 
 	var wg sync.WaitGroup
@@ -115,10 +115,10 @@ func (a *App) Shutdown() {
 			defer wg.Done()
 			err := s.Shutdown(context.Background())
 			if err != nil {
-				logger.Printf("ZeroDT: server %s has been shutdown with: %v", s.Addr, err)
+				logger.Printf("server %s has been shutdown with: %v", s.Addr, err)
 				return
 			}
-			logger.Printf("ZeroDT: server %s has been shutdown", s.Addr)
+			logger.Printf("server %s has been shutdown", s.Addr)
 		}(s)
 	}
 
@@ -132,11 +132,11 @@ func (a *App) Shutdown() {
 func (a *App) ListenAndServe() error {
 	inherited, messenger, err := inherit()
 	if err != nil {
-		logger.Printf("ZeroDT: failed to inherit listeners with: '%v'", err)
+		logger.Printf("failed to inherit listeners with: '%v'", err)
 		return err
 	}
 	e := newExchange(inherited)
-	logger.Printf("ZeroDT: serving with pid='%d', inherited='%s'", os.Getpid(), formatInherited(e))
+	logger.Printf("serving with pid='%d', inherited='%s'", os.Getpid(), formatInherited(e))
 
 	// Signals wait group.
 	var sigWG sync.WaitGroup
@@ -170,20 +170,20 @@ func (a *App) ListenAndServe() error {
 
 			l, err := e.acquireOrCreateListener("tcp", s.Addr)
 			if err != nil {
-				logger.Printf("ZeroDT: failed to listen on %v with: %v", s.Addr, err)
+				logger.Printf("failed to listen on %v with: %v", s.Addr, err)
 				return
 			}
 			// A server is about to Serve and already listen.
 			startOnce.Done()
 			// Wait for parent to start if set.
 			parentWG.Wait()
 			if startErr != nil {
-				logger.Printf("ZeroDT: server %v exited with: %v", s.Addr, startErr)
+				logger.Printf("server %v exited with: %v", s.Addr, startErr)
 				return
 			}
 			// TODO: shutdown all servers in case of error
 			err = s.Serve(&notifyListener{Listener: tcpKeepAliveListener{l}, doneOnce: servedOnce})
-			logger.Printf("ZeroDT: server %v has finished serving with: %v", s.Addr, err)
+			logger.Printf("server %v has finished serving with: %v", s.Addr, err)
 		}(s)
 	}
 
@@ -219,7 +219,7 @@ func (a *App) ListenAndServe() error {
 }
 
 func (a *App) handleSignals(ctx context.Context, wg *sync.WaitGroup, e *exchange) {
-	defer logger.Printf("ZeroDT: stop handling signals")
+	defer logger.Printf("stop handling signals")
 	defer wg.Done()
 
 	signals := make(chan os.Signal, 10)
@@ -241,7 +241,7 @@ CatchSignals:
 			return
 		// OS signal.
 		case s := <-signals:
-			logger.Printf("ZeroDT: %v signal...", s)
+			logger.Printf("%v signal...", s)
 			switch s {
 			// Shutdown servers. No exit here.
 			case syscall.SIGINT, syscall.SIGTERM:
@@ -251,12 +251,12 @@ CatchSignals:
 			case syscall.SIGUSR2:
 				_, f, err := forkExec(e.activeFiles())
 				if err != nil {
-					logger.Printf("ZeroDT: failed to forkExec: '%v'", err)
+					logger.Printf("failed to forkExec: '%v'", err)
 					continue CatchSignals
 				}
 				m, err := ListenSocket(f)
 				if err != nil {
-					logger.Printf("ZeroDT: failed to listen communication socket: '%v'", err)
+					logger.Printf("failed to listen communication socket: '%v'", err)
 					continue CatchSignals
 				}
 				// Nothing to do with errors.
@@ -353,21 +353,21 @@ func protocolActAsParent(m *StreamMessenger, waitChildTimeout time.Duration, wai
 	m.SetDeadline(time.Now().Add(waitChildTimeout))
 
 	// Child->Parent, ready message.
-	logger.Printf("ZeroDT: waiting for readyMsg...")
+	logger.Printf("waiting for readyMsg...")
 	r := readyMsg{}
 	err := m.Recv(&r)
 	if err != nil {
-		logger.Printf("ZeroDT: Parent<=>Child communication failed with: '%v'", err)
+		logger.Printf("Parent<=>Child communication failed with: '%v'", err)
 		// The child will die by timout.
 		return err
 	}
 
 	// Parent->Child, ready confirmation message.
-	logger.Printf("ZeroDT: sending readyConfirmationMsg to the child...")
+	logger.Printf("sending readyConfirmationMsg to the child...")
 	tipTimeout := maxTimeout(r.WaitParentShutdownTimeout, waitParentShutdownTimeout)
 	err = m.Send(readyConfirmationMsg{FixedWaitParentShutdownTimeout: tipTimeout})
 	if err != nil {
-		logger.Printf("ZeroDT: Parent<=>Child communication failed with: '%v'", err)
+		logger.Printf("Parent<=>Child communication failed with: '%v'", err)
 		// The child will die by timout.
 		return err
 	}
@@ -377,11 +377,11 @@ func protocolActAsParent(m *StreamMessenger, waitChildTimeout time.Duration, wai
 	//
 
 	// Child->Parent, accepted message.
-	logger.Printf("ZeroDT: waiting for acceptedMsg...")
+	logger.Printf("waiting for acceptedMsg...")
 	a := acceptedMsg{}
 	err = m.Recv(&a)
 	if err != nil {
-		logger.Printf("ZeroDT: Parent<=>Child communication failed with: '%v'", err)
+		logger.Printf("Parent<=>Child communication failed with: '%v'", err)
 	}
 
 	// Shutdown callback.
@@ -391,11 +391,11 @@ func protocolActAsParent(m *StreamMessenger, waitChildTimeout time.Duration, wai
 	if tipTimeout == 0 {
 		return nil
 	}
-	logger.Printf("ZeroDT: sending shutdownConfirmationMsg to the child...")
+	logger.Printf("sending shutdownConfirmationMsg to the child...")
 	m.SetDeadline(time.Now().Add(sendTimeout))
 	err = m.Send(shutdownConfirmationMsg{})
 	if err != nil {
-		logger.Printf("ZeroDT: Parent<=>Child communication failed with: '%v'", err)
+		logger.Printf("Parent<=>Child communication failed with: '%v'", err)
 	}
 	return nil
 }
@@ -404,21 +404,21 @@ func protocolActAsChild(m *StreamMessenger, waitChildTimeout time.Duration, wait
 	defer m.Close()
 
 	// Child->Parent, ready message.
-	logger.Printf("ZeroDT: sending readyMsg to the parent...")
+	logger.Printf("sending readyMsg to the parent...")
 	m.SetDeadline(time.Now().Add(sendTimeout))
 	err := m.Send(readyMsg{WaitParentShutdownTimeout: waitParentShutdownTimeout})
 	if err != nil {
-		logger.Printf("ZeroDT: Parent<=>Child communication failed with: '%v'", err)
+		logger.Printf("Parent<=>Child communication failed with: '%v'", err)
 		return err
 	}
 
 	// Parent->Child, ready confirmation message.
-	logger.Printf("ZeroDT: waiting for readyConfirmationMsg...")
+	logger.Printf("waiting for readyConfirmationMsg...")
 	rcr := readyConfirmationMsg{}
 	m.SetDeadline(time.Now().Add(maxTimeout(waitChildTimeout, waitParentShutdownTimeout)))
 	err = m.Recv(&rcr)
 	if err != nil {
-		logger.Printf("ZeroDT: Parent<=>Child communication failed with: '%v'", err)
+		logger.Printf("Parent<=>Child communication failed with: '%v'", err)
 		return err
 	}
 
@@ -429,29 +429,29 @@ func protocolActAsChild(m *StreamMessenger, waitChildTimeout time.Duration, wait
 	notifyFn()
 
 	// Child->Parent, accepted message.
-	logger.Printf("ZeroDT: sending acceptedMsg...")
+	logger.Printf("sending acceptedMsg...")
 	m.SetDeadline(time.Now().Add(sendTimeout))
 	err = m.Send(acceptedMsg{})
 	if err != nil {
-		logger.Printf("ZeroDT: Parent<=>Child communication failed with: '%v'", err)
+		logger.Printf("Parent<=>Child communication failed with: '%v'", err)
 	}
 
 	if rcr.FixedWaitParentShutdownTimeout == 0 {
 		return nil
 	}
 
 	// Parent->Child, shutdown confirmation message.
-	logger.Printf("ZeroDT: waiting for shutdownConfirmationMsg...")
+	logger.Printf("waiting for shutdownConfirmationMsg...")
 	scr := shutdownConfirmationMsg{}
 	m.SetDeadline(time.Now().Add(rcr.FixedWaitParentShutdownTimeout))
 	err = m.Recv(&scr)
 	if err != nil {
-		logger.Printf("ZeroDT: Parent<=>Child communication failed with: '%v'", err)
+		logger.Printf("Parent<=>Child communication failed with: '%v'", err)
 		if opErr, ok := err.(*net.OpError); ok {
 			if opErr.Timeout() {
 				// There are issues on parent's side probably. Need to kill parent.
 				parentPID, err := killParent()
-				logger.Printf("ZeroDT: parent %d was killed with: '%v'", parentPID, err)
+				logger.Printf("parent %d was killed with: '%v'", parentPID, err)
 				return nil
 			}
 		}

examples/test/main.go

@@ -9,8 +9,8 @@ import (
 	"strconv"
 	"time"
 
-	"github.com/Sirupsen/logrus"
 	"github.com/gorilla/mux"
+	"github.com/sirupsen/logrus"
 	"github.com/ssgreg/zerodt"
 )
 

exchange.go

@@ -97,7 +97,7 @@ func (e *exchange) acquireOrCreateListener(netStr, addrStr string) (*net.TCPList
 	// Try to acquire one of inherited listeners.
 	l := e.acquireListener(addr)
 	if l != nil {
-		logger.Printf("ZeroDT: listener '%v' acquired", addr)
+		logger.Printf("listener '%v' acquired", addr)
 		return l, nil
 	}
 
@@ -111,7 +111,7 @@ func (e *exchange) acquireOrCreateListener(netStr, addrStr string) (*net.TCPList
 		l.Close()
 		return nil, err
 	}
-	logger.Printf("ZeroDT: listener '%v' created", addr)
+	logger.Printf("listener '%v' created", addr)
 
 	return l, nil
 }

logger.go

@@ -15,21 +15,32 @@ type StdLogger interface {
 	Print(...interface{})
 	Printf(string, ...interface{})
 	Println(...interface{})
-
-	Fatal(...interface{})
-	Fatalf(string, ...interface{})
-	Fatalln(...interface{})
-
-	Panic(...interface{})
-	Panicf(string, ...interface{})
-	Panicln(...interface{})
 }
 
 var (
 	// logger discards all log messages by default
 	logger StdLogger = log.New(ioutil.Discard, "", 0)
 )
 
+type prefixLogger struct {
+	StdLogger
+	prefix string
+}
+
+func (l *prefixLogger) Print(args ...interface{}) {
+	args = append([]interface{}{l.prefix}, args...)
+	l.StdLogger.Print(args...)
+}
+
+func (l *prefixLogger) Printf(format string, args ...interface{}) {
+	l.StdLogger.Printf(l.prefix+" "+format, args...)
+}
+
+func (l *prefixLogger) Println(args ...interface{}) {
+	args = append([]interface{}{l.prefix}, args...)
+	l.StdLogger.Println(args...)
+}
+
 // SetLogger allows to set a different logger that is compatible with StdLogger
 // interface. Tested with stdlib logger:
 //
@@ -40,5 +51,5 @@ var (
 //   logrus.StandardLogger()
 //
 func SetLogger(l StdLogger) {
-	logger = l
+	logger = &prefixLogger{StdLogger: l, prefix: "zerodt:"}
 }