flush log messages to file

Author: mihaibuzgau

main.go

@@ -3,13 +3,15 @@ package main
 import (
 	"flag"
 	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"runtime"
+
 	"github.com/cloudfoundry-incubator/cf-mssql-broker/config"
 	"github.com/cloudfoundry-incubator/cf-mssql-broker/provisioner"
 	"github.com/pivotal-cf/brokerapi"
 	"github.com/pivotal-golang/lager"
-	"net/http"
-	"os"
-	"runtime"
 )
 
 type exitOnPanicWrapper struct {
@@ -76,7 +78,7 @@ func getLogLevel(config *config.Config) lager.LogLevel {
 	return minLogLevel
 }
 
-func runMain() {
+func runMain(writer io.Writer) {
 
 	if !flag.Parsed() {
 		flag.Parse()
@@ -88,7 +90,7 @@ func runMain() {
 		panic(fmt.Errorf("configuration load error from file %s. Err: %s", *configFile, err))
 	}
 
-	logger.RegisterSink(lager.NewWriterSink(os.Stdout, getLogLevel(brokerConfig)))
+	logger.RegisterSink(lager.NewWriterSink(writer, getLogLevel(brokerConfig)))
 
 	logger.Debug("config-load-success", lager.Data{"file-source": *configFile, "config": brokerConfig})
 

main_nonwindows.go

@@ -2,6 +2,8 @@
 
 package main
 
+import "os"
+
 func main() {
-	runMain()
+	runMain(os.Stdout)
 }

main_windows.go

@@ -4,18 +4,20 @@ package main
 
 import (
 	"flag"
-	"golang.org/x/sys/windows/svc"
-	"log"
+	"io"
 	"os"
 	"path"
+
+	"golang.org/x/sys/windows/svc"
 )
 
 type WindowsService struct {
+	writer io.Writer
 }
 
 func (ws *WindowsService) Execute(args []string, r <-chan svc.ChangeRequest, s chan<- svc.Status) (svcSpecificEC bool, exitCode uint32) {
 	s <- svc.Status{State: svc.Running, Accepts: svc.AcceptStop | svc.AcceptShutdown | svc.AcceptPauseAndContinue}
-	go runMain()
+	go runMain(ws.writer)
 
 loop:
 	for {
@@ -43,38 +45,9 @@ loop:
 	return
 }
 
-func redirectStdStreams(logDir string) error {
-
-	if logDir == "" {
-		workingDir, err := os.Getwd()
-		if err != nil {
-			return err
-		}
-		logDir = path.Join(workingDir, "logs")
-	}
-	if _, err := os.Stat(logDir); os.IsNotExist(err) {
-		err := os.Mkdir(logDir, 0666)
-		if err != nil {
-			return err
-		}
-	}
-
-	logFilePath := path.Join(logDir, "mssql_broker.log")
-
-	logFile, err := os.OpenFile(logFilePath, os.O_WRONLY|os.O_CREATE|os.O_APPEND|os.O_SYNC, 0660)
-	if err != nil {
-		return err
-	}
-
-	log.SetOutput(logFile)
-	os.Stderr = logFile
-	os.Stdout = logFile
-
-	return nil
-}
-
 func main() {
-	var logDir = flag.String("logDir", "", "The directory where the logs will be stored")
+	var logDir = ""
+ 	flag.StringVar(&logDir, "logDir","", "The directory where the logs will be stored")
 	var serviceName = flag.String("serviceName", "mssql_broker", "The name of the service as installed in Windows SCM")
 
 	if !flag.Parsed() {
@@ -87,17 +60,42 @@ func main() {
 	}
 
 	if interactiveMode {
-		runMain()
+		runMain(os.Stdout)
 	} else {
 		var err error
-		//setting stdout, stderr and log output
-		err = redirectStdStreams(*logDir)
 
+		if logDir == "" {
+			//will default to %windir%\System32\
+			workingDir, err := os.Getwd()
+			if err != nil {
+				panic(err.Error())
+			}
+			logDir = path.Join(workingDir, "logs")
+		}
+		if _, err := os.Stat(logDir); os.IsNotExist(err) {
+			err := os.Mkdir(logDir, 0666)
+			if err != nil {
+				panic(err.Error())
+			}
+		}
+
+		logFilePath := path.Join(logDir, "mssql_broker.log")
+
+		logFile, err := os.OpenFile(logFilePath, os.O_WRONLY|os.O_CREATE|os.O_APPEND|os.O_SYNC, 0660)
 		if err != nil {
 			panic(err.Error())
 		}
+		defer logFile.Close()
 
-		ws := WindowsService{}
+		//setting stderr & stdout
+		os.Stdout = logFile
+		os.Stderr = logFile
+
+		fileWriter := NewWinFileWriter(logFile)
+
+		ws := WindowsService{
+			writer: fileWriter,
+		}
 
 		err = svc.Run(*serviceName, &ws)
 		if err != nil {

winfilewriter.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"os"
+)
+
+type winFileWriter struct {
+	file *os.File
+}
+
+func NewWinFileWriter(file *os.File) *winFileWriter {
+	return &winFileWriter{
+		file: file,
+	}
+}
+
+func (wfw *winFileWriter) Write(p []byte) (n int, err error) {
+	n, err = wfw.file.Write(p)
+
+	wfw.file.Sync()
+
+	return n, err
+}