rclone/fs/log/log.go
Nick Craig-Wood c98dd8755c log: fix enabling systemd logging when using --log-file
This also moves all the systemd logging decisions to fs/log
2020-12-17 11:55:27 +00:00

182 lines
4.7 KiB
Go

// Package log provides logging for rclone
package log
import (
"context"
"fmt"
"io"
"log"
"os"
"reflect"
"runtime"
"strings"
systemd "github.com/iguanesolutions/go-systemd/v5"
sysdjournald "github.com/iguanesolutions/go-systemd/v5/journald"
"github.com/rclone/rclone/fs"
"github.com/sirupsen/logrus"
)
// Options contains options for controlling the logging
type Options struct {
File string // Log everything to this file
Format string // Comma separated list of log format options
UseSyslog bool // Use Syslog for logging
SyslogFacility string // Facility for syslog, e.g. KERN,USER,...
LogSystemdSupport bool // set if using systemd logging
}
// DefaultOpt is the default values used for Opt
var DefaultOpt = Options{
Format: "date,time",
SyslogFacility: "DAEMON",
}
// Opt is the options for the logger
var Opt = DefaultOpt
// fnName returns the name of the calling +2 function
func fnName() string {
pc, _, _, ok := runtime.Caller(2)
name := "*Unknown*"
if ok {
name = runtime.FuncForPC(pc).Name()
dot := strings.LastIndex(name, ".")
if dot >= 0 {
name = name[dot+1:]
}
}
return name
}
// Trace debugs the entry and exit of the calling function
//
// It is designed to be used in a defer statement so it returns a
// function that logs the exit parameters.
//
// Any pointers in the exit function will be dereferenced
func Trace(o interface{}, format string, a ...interface{}) func(string, ...interface{}) {
if fs.GetConfig(context.Background()).LogLevel < fs.LogLevelDebug {
return func(format string, a ...interface{}) {}
}
name := fnName()
fs.LogPrintf(fs.LogLevelDebug, o, name+": "+format, a...)
return func(format string, a ...interface{}) {
for i := range a {
// read the values of the pointed to items
typ := reflect.TypeOf(a[i])
if typ.Kind() == reflect.Ptr {
value := reflect.ValueOf(a[i])
if value.IsNil() {
a[i] = nil
} else {
pointedToValue := reflect.Indirect(value)
a[i] = pointedToValue.Interface()
}
}
}
fs.LogPrintf(fs.LogLevelDebug, o, ">"+name+": "+format, a...)
}
}
// Stack logs a stack trace of callers with the o and info passed in
func Stack(o interface{}, info string) {
if fs.GetConfig(context.Background()).LogLevel < fs.LogLevelDebug {
return
}
arr := [16 * 1024]byte{}
buf := arr[:]
n := runtime.Stack(buf, false)
buf = buf[:n]
fs.LogPrintf(fs.LogLevelDebug, o, "%s\nStack trace:\n%s", info, buf)
}
// InitLogging start the logging as per the command line flags
func InitLogging() {
flagsStr := "," + Opt.Format + ","
var flags int
if strings.Contains(flagsStr, ",date,") {
flags |= log.Ldate
}
if strings.Contains(flagsStr, ",time,") {
flags |= log.Ltime
}
if strings.Contains(flagsStr, ",microseconds,") {
flags |= log.Lmicroseconds
}
if strings.Contains(flagsStr, ",UTC,") {
flags |= log.LUTC
}
if strings.Contains(flagsStr, ",longfile,") {
flags |= log.Llongfile
}
if strings.Contains(flagsStr, ",shortfile,") {
flags |= log.Lshortfile
}
log.SetFlags(flags)
// Log file output
if Opt.File != "" {
f, err := os.OpenFile(Opt.File, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0640)
if err != nil {
log.Fatalf("Failed to open log file: %v", err)
}
_, err = f.Seek(0, io.SeekEnd)
if err != nil {
fs.Errorf(nil, "Failed to seek log file to end: %v", err)
}
log.SetOutput(f)
logrus.SetOutput(f)
redirectStderr(f)
}
// Syslog output
if Opt.UseSyslog {
if Opt.File != "" {
log.Fatalf("Can't use --syslog and --log-file together")
}
startSysLog()
}
// Activate systemd logger support if systemd invocation ID is
// detected and output is going to stderr (not logging to a file or syslog)
if !Redirected() {
if _, usingSystemd := systemd.GetInvocationID(); usingSystemd {
Opt.LogSystemdSupport = true
}
}
// Systemd logging output
if Opt.LogSystemdSupport {
startSystemdLog()
}
}
// Redirected returns true if the log has been redirected from stdout
func Redirected() bool {
return Opt.UseSyslog || Opt.File != ""
}
var logLevelToStringSystemd = []string{
fs.LogLevelEmergency: sysdjournald.EmergPrefix,
fs.LogLevelAlert: sysdjournald.AlertPrefix,
fs.LogLevelCritical: sysdjournald.CritPrefix,
fs.LogLevelError: sysdjournald.ErrPrefix,
fs.LogLevelWarning: sysdjournald.WarningPrefix,
fs.LogLevelNotice: sysdjournald.NoticePrefix,
fs.LogLevelInfo: sysdjournald.InfoPrefix,
fs.LogLevelDebug: sysdjournald.DebugPrefix,
}
// Starts systemd logging
func startSystemdLog() {
log.SetFlags(0)
fs.LogPrint = func(level fs.LogLevel, text string) {
var prefix string
if level < fs.LogLevel(len(logLevelToStringSystemd)) {
prefix = logLevelToStringSystemd[level]
}
text = fmt.Sprintf("%s%-6s: %s", prefix, level, text)
_ = log.Output(4, text)
}
}