init.go, main.go: don't use logs.ConfigureLogging

This function is somewhat strange and I always wanted to remove it,
as it tries to satisfy both init.go and main.go, which have somewhat
different needs.

It is more straightforward and readable to configure logrus directly.

While at it, simplify errors on panic (errors from logrus.ParseLevel
and strconv.Atoi already contain value which they fail to parse, and
panic already contains enough context to figure out what's wrong).

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

init.go

@@ -1,13 +1,11 @@
 package main
 
 import (
-	"fmt"
 	"os"
 	"runtime"
 	"strconv"
 
 	"github.com/opencontainers/runc/libcontainer"
-	"github.com/opencontainers/runc/libcontainer/logs"
 	_ "github.com/opencontainers/runc/libcontainer/nsenter"
 	"github.com/sirupsen/logrus"
 )
@@ -19,25 +17,19 @@ func init() {
 		runtime.GOMAXPROCS(1)
 		runtime.LockOSThread()
 
-		level := os.Getenv("_LIBCONTAINER_LOGLEVEL")
-		logLevel, err := logrus.ParseLevel(level)
+		logLevel, err := logrus.ParseLevel(os.Getenv("_LIBCONTAINER_LOGLEVEL"))
 		if err != nil {
-			panic(fmt.Sprintf("libcontainer: failed to parse log level: %q: %v", level, err))
+			panic(err)
 		}
 
-		logPipeFdStr := os.Getenv("_LIBCONTAINER_LOGPIPE")
-		logPipeFd, err := strconv.Atoi(logPipeFdStr)
+		logPipeFd, err := strconv.Atoi(os.Getenv("_LIBCONTAINER_LOGPIPE"))
 		if err != nil {
-			panic(fmt.Sprintf("libcontainer: failed to convert environment variable _LIBCONTAINER_LOGPIPE=%s to int: %s", logPipeFdStr, err))
-		}
-		err = logs.ConfigureLogging(logs.Config{
-			LogPipeFd: logPipeFd,
-			LogFormat: "json",
-			LogLevel:  logLevel,
-		})
-		if err != nil {
-			panic(fmt.Sprintf("libcontainer: failed to configure logging: %v", err))
+			panic(err)
 		}
+
+		logrus.SetLevel(logLevel)
+		logrus.SetOutput(os.NewFile(uintptr(logPipeFd), "logpipe"))
+		logrus.SetFormatter(new(logrus.JSONFormatter))
 		logrus.Debug("child process in init()")
 
 		factory, _ := libcontainer.New("")

main.go

@@ -1,13 +1,13 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"os"
 	"runtime"
 	"strings"
 
-	"github.com/opencontainers/runc/libcontainer/logs"
 	"github.com/opencontainers/runc/libcontainer/seccomp"
 	"github.com/opencontainers/runtime-spec/specs-go"
 
@@ -149,7 +149,7 @@ func main() {
 			return err
 		}
 
-		return logs.ConfigureLogging(createLogConfig(context))
+		return configLogrus(context)
 	}
 
 	// If the command returns an error, cli takes upon itself to print
@@ -173,22 +173,30 @@ func (f *FatalWriter) Write(p []byte) (n int, err error) {
 	return len(p), nil
 }
 
-func createLogConfig(context *cli.Context) logs.Config {
-	logFilePath := context.GlobalString("log")
-	logPipeFd := 0
-	if logFilePath == "" {
-		logPipeFd = 2
-	}
-	config := logs.Config{
-		LogPipeFd:   logPipeFd,
-		LogLevel:    logrus.InfoLevel,
-		LogFilePath: logFilePath,
-		LogFormat:   context.GlobalString("log-format"),
-		LogCaller:   context.GlobalBool("debug"),
-	}
+func configLogrus(context *cli.Context) error {
 	if context.GlobalBool("debug") {
-		config.LogLevel = logrus.DebugLevel
+		logrus.SetLevel(logrus.DebugLevel)
+		logrus.SetReportCaller(true)
 	}
 
-	return config
+	switch f := context.GlobalString("log-format"); f {
+	case "":
+		// do nothing
+	case "text":
+		// do nothing
+	case "json":
+		logrus.SetFormatter(new(logrus.JSONFormatter))
+	default:
+		return errors.New("invalid log-format: " + f)
+	}
+
+	if file := context.GlobalString("log"); file != "" {
+		f, err := os.OpenFile(file, os.O_CREATE|os.O_WRONLY|os.O_APPEND|os.O_SYNC, 0o644)
+		if err != nil {
+			return err
+		}
+		logrus.SetOutput(f)
+	}
+
+	return nil
 }