cloudflared-mirror/logger/create.go

233 lines
5.8 KiB
Go

package logger
import (
"fmt"
"io"
"os"
"path"
"path/filepath"
"sync"
"time"
"github.com/mattn/go-colorable"
"github.com/rs/zerolog"
fallbacklog "github.com/rs/zerolog/log"
"github.com/urfave/cli/v2"
"golang.org/x/term"
"gopkg.in/natefinch/lumberjack.v2"
)
const (
EnableTerminalLog = false
DisableTerminalLog = true
LogLevelFlag = "loglevel"
LogFileFlag = "logfile"
LogDirectoryFlag = "log-directory"
LogTransportLevelFlag = "transport-loglevel"
LogSSHDirectoryFlag = "log-directory"
LogSSHLevelFlag = "log-level"
dirPermMode = 0744 // rwxr--r--
filePermMode = 0644 // rw-r--r--
consoleTimeFormat = time.RFC3339
)
func init() {
zerolog.TimestampFunc = utcNow
}
func utcNow() time.Time {
return time.Now().UTC()
}
func fallbackLogger(err error) *zerolog.Logger {
failLog := fallbacklog.With().Logger()
fallbacklog.Error().Msgf("Falling back to a default logger due to logger setup failure: %s", err)
return &failLog
}
type resilientMultiWriter struct {
writers []io.Writer
}
// This custom resilientMultiWriter is an alternative to zerolog's so that we can make it resilient to individual
// writer's errors. E.g., when running as a Windows service, the console writer fails, but we don't want to
// allow that to prevent all logging to fail due to breaking the for loop upon an error.
func (t resilientMultiWriter) Write(p []byte) (n int, err error) {
for _, w := range t.writers {
_, _ = w.Write(p)
}
return len(p), nil
}
func newZerolog(loggerConfig *Config) *zerolog.Logger {
var writers []io.Writer
if loggerConfig.ConsoleConfig != nil {
writers = append(writers, createConsoleLogger(*loggerConfig.ConsoleConfig))
}
if loggerConfig.FileConfig != nil {
fileLogger, err := createFileWriter(*loggerConfig.FileConfig)
if err != nil {
return fallbackLogger(err)
}
writers = append(writers, fileLogger)
}
if loggerConfig.RollingConfig != nil {
rollingLogger, err := createRollingLogger(*loggerConfig.RollingConfig)
if err != nil {
return fallbackLogger(err)
}
writers = append(writers, rollingLogger)
}
multi := resilientMultiWriter{writers}
level, err := zerolog.ParseLevel(loggerConfig.MinLevel)
if err != nil {
return fallbackLogger(err)
}
log := zerolog.New(multi).With().Timestamp().Logger().Level(level)
return &log
}
func CreateTransportLoggerFromContext(c *cli.Context, disableTerminal bool) *zerolog.Logger {
return createFromContext(c, LogTransportLevelFlag, LogDirectoryFlag, disableTerminal)
}
func CreateLoggerFromContext(c *cli.Context, disableTerminal bool) *zerolog.Logger {
return createFromContext(c, LogLevelFlag, LogDirectoryFlag, disableTerminal)
}
func CreateSSHLoggerFromContext(c *cli.Context, disableTerminal bool) *zerolog.Logger {
return createFromContext(c, LogSSHLevelFlag, LogSSHDirectoryFlag, disableTerminal)
}
func createFromContext(
c *cli.Context,
logLevelFlagName,
logDirectoryFlagName string,
disableTerminal bool,
) *zerolog.Logger {
logLevel := c.String(logLevelFlagName)
logFile := c.String(LogFileFlag)
logDirectory := c.String(logDirectoryFlagName)
loggerConfig := CreateConfig(
logLevel,
disableTerminal,
logDirectory,
logFile,
)
log := newZerolog(loggerConfig)
if incompatibleFlagsSet := logFile != "" && logDirectory != ""; incompatibleFlagsSet {
log.Error().Msgf("Your config includes values for both %s and %s, but they are incompatible. %s takes precedence.", LogFileFlag, logDirectoryFlagName, LogFileFlag)
}
return log
}
func Create(loggerConfig *Config) *zerolog.Logger {
if loggerConfig == nil {
loggerConfig = &Config{
defaultConfig.ConsoleConfig,
nil,
nil,
defaultConfig.MinLevel,
}
}
return newZerolog(loggerConfig)
}
func createConsoleLogger(config ConsoleConfig) io.Writer {
consoleOut := os.Stderr
return zerolog.ConsoleWriter{
Out: colorable.NewColorable(consoleOut),
NoColor: config.noColor || !term.IsTerminal(int(consoleOut.Fd())),
TimeFormat: consoleTimeFormat,
}
}
type fileInitializer struct {
once sync.Once
writer io.Writer
creationError error
}
var (
singleFileInit fileInitializer
rotatingFileInit fileInitializer
)
func createFileWriter(config FileConfig) (io.Writer, error) {
singleFileInit.once.Do(func() {
var logFile io.Writer
fullpath := config.Fullpath()
// Try to open the existing file
logFile, err := os.OpenFile(fullpath, os.O_APPEND|os.O_WRONLY, filePermMode)
if err != nil {
// If the existing file wasn't found, or couldn't be opened, just ignore
// it and recreate a new one.
logFile, err = createDirFile(config)
// If creating a new logfile fails, then we have no choice but to error out.
if err != nil {
singleFileInit.creationError = err
return
}
}
singleFileInit.writer = logFile
})
return singleFileInit.writer, singleFileInit.creationError
}
func createDirFile(config FileConfig) (io.Writer, error) {
if config.Dirname != "" {
err := os.MkdirAll(config.Dirname, dirPermMode)
if err != nil {
return nil, fmt.Errorf("unable to create directories for new logfile: %s", err)
}
}
mode := os.FileMode(filePermMode)
fullPath := filepath.Join(config.Dirname, config.Filename)
logFile, err := os.OpenFile(fullPath, os.O_CREATE|os.O_WRONLY|os.O_APPEND, mode)
if err != nil {
return nil, fmt.Errorf("unable to create a new logfile: %s", err)
}
return logFile, nil
}
func createRollingLogger(config RollingConfig) (io.Writer, error) {
rotatingFileInit.once.Do(func() {
if err := os.MkdirAll(config.Dirname, dirPermMode); err != nil {
rotatingFileInit.creationError = err
return
}
rotatingFileInit.writer = &lumberjack.Logger{
Filename: path.Join(config.Dirname, config.Filename),
MaxBackups: config.maxBackups,
MaxSize: config.maxSize,
MaxAge: config.maxAge,
}
})
return rotatingFileInit.writer, rotatingFileInit.creationError
}