Update dependency opencontainer/runc

vendor/github.com/opencontainers/runc/libcontainer/logs/logs.go

@@ -0,0 +1,102 @@
+package logs
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"sync"
+
+	"github.com/sirupsen/logrus"
+)
+
+var (
+	configureMutex = sync.Mutex{}
+	// loggingConfigured will be set once logging has been configured via invoking `ConfigureLogging`.
+	// Subsequent invocations of `ConfigureLogging` would be no-op
+	loggingConfigured = false
+)
+
+type Config struct {
+	LogLevel    logrus.Level
+	LogFormat   string
+	LogFilePath string
+	LogPipeFd   string
+}
+
+func ForwardLogs(logPipe io.Reader) {
+	lineReader := bufio.NewReader(logPipe)
+	for {
+		line, err := lineReader.ReadBytes('\n')
+		if len(line) > 0 {
+			processEntry(line)
+		}
+		if err == io.EOF {
+			logrus.Debugf("log pipe has been closed: %+v", err)
+			return
+		}
+		if err != nil {
+			logrus.Errorf("log pipe read error: %+v", err)
+		}
+	}
+}
+
+func processEntry(text []byte) {
+	type jsonLog struct {
+		Level string `json:"level"`
+		Msg   string `json:"msg"`
+	}
+
+	var jl jsonLog
+	if err := json.Unmarshal(text, &jl); err != nil {
+		logrus.Errorf("failed to decode %q to json: %+v", text, err)
+		return
+	}
+
+	lvl, err := logrus.ParseLevel(jl.Level)
+	if err != nil {
+		logrus.Errorf("failed to parse log level %q: %v\n", jl.Level, err)
+		return
+	}
+	logrus.StandardLogger().Logf(lvl, jl.Msg)
+}
+
+func ConfigureLogging(config Config) error {
+	configureMutex.Lock()
+	defer configureMutex.Unlock()
+
+	if loggingConfigured {
+		logrus.Debug("logging has already been configured")
+		return nil
+	}
+
+	logrus.SetLevel(config.LogLevel)
+
+	if config.LogPipeFd != "" {
+		logPipeFdInt, err := strconv.Atoi(config.LogPipeFd)
+		if err != nil {
+			return fmt.Errorf("failed to convert _LIBCONTAINER_LOGPIPE environment variable value %q to int: %v", config.LogPipeFd, err)
+		}
+		logrus.SetOutput(os.NewFile(uintptr(logPipeFdInt), "logpipe"))
+	} else if config.LogFilePath != "" {
+		f, err := os.OpenFile(config.LogFilePath, os.O_CREATE|os.O_WRONLY|os.O_APPEND|os.O_SYNC, 0644)
+		if err != nil {
+			return err
+		}
+		logrus.SetOutput(f)
+	}
+
+	switch config.LogFormat {
+	case "text":
+		// retain logrus's default.
+	case "json":
+		logrus.SetFormatter(new(logrus.JSONFormatter))
+	default:
+		return fmt.Errorf("unknown log-format %q", config.LogFormat)
+	}
+
+	loggingConfigured = true
+	return nil
+}