focalboard/server/services/mlog/mlog.go
2021-07-15 11:42:53 -04:00

281 lines
8.4 KiB
Go

// Package mlog provides a simple wrapper around Logr.
package mlog
import (
"context"
"encoding/json"
"fmt"
"io/ioutil"
"log"
"os"
"runtime"
"strings"
"time"
"github.com/mattermost/logr/v2"
logrcfg "github.com/mattermost/logr/v2/config"
)
const (
ShutdownTimeout = time.Second * 15
)
var (
mlogPkg string
)
func init() {
// Calc current package name
pcs := make([]uintptr, 2)
_ = runtime.Callers(0, pcs)
tmp := runtime.FuncForPC(pcs[1]).Name()
mlogPkg = GetPackageName(tmp)
}
// Type and function aliases from Logr to limit the spread of dependencies throughout Focalboard.
type Field = logr.Field
type Level = logr.Level
type Option = logr.Option
type Target = logr.Target
type LogRec = logr.LogRec
type LogCloner = logr.LogCloner
type MetricsCollector = logr.MetricsCollector
// Any picks the best supported field type based on type of val.
// For best performance when passing a struct (or struct pointer),
// implement `logr.LogWriter` on the struct, otherwise reflection
// will be used to generate a string representation.
var Any = logr.Any
// Int64 constructs a field containing a key and Int64 value.
var Int64 = logr.Int64
// Int32 constructs a field containing a key and Int32 value.
var Int32 = logr.Int32
// Int constructs a field containing a key and Int value.
var Int = logr.Int
// Uint64 constructs a field containing a key and Uint64 value.
var Uint64 = logr.Uint64
// Uint32 constructs a field containing a key and Uint32 value.
var Uint32 = logr.Uint32
// Uint constructs a field containing a key and Uint value.
var Uint = logr.Uint
// Float64 constructs a field containing a key and Float64 value.
var Float64 = logr.Float64
// Float32 constructs a field containing a key and Float32 value.
var Float32 = logr.Float32
// String constructs a field containing a key and String value.
var String = logr.String
// Stringer constructs a field containing a key and a fmt.Stringer value.
// The fmt.Stringer's `String` method is called lazily.
var Stringer = logr.Stringer
// Err constructs a field containing a default key ("error") and error value.
var Err = logr.Err
// NamedErr constructs a field containing a key and error value.
var NamedErr = logr.NamedErr
// Bool constructs a field containing a key and bool value.
var Bool = logr.Bool
// Time constructs a field containing a key and time.Time value.
var Time = logr.Time
// Duration constructs a field containing a key and time.Duration value.
var Duration = logr.Duration
// Millis constructs a field containing a key and timestamp value.
// The timestamp is expected to be milliseconds since Jan 1, 1970 UTC.
var Millis = logr.Millis
// Array constructs a field containing a key and array value.
var Array = logr.Array
// Map constructs a field containing a key and map value.
var Map = logr.Map
// LoggerConfig is a map of LogTarget configurations.
type LoggerConfig map[string]logrcfg.TargetCfg
func (lc LoggerConfig) append(cfg LoggerConfig) {
for k, v := range cfg {
lc[k] = v
}
}
// Logger provides a thin wrapper around a Logr instance. This is a struct instead of an interface
// so that there are no allocations on the heap each interface method invocation. Normally not
// something to be concerned about, but logging calls for disabled levels should have as little CPU
// and memory impact as possible. Most of these wrapper calls will be inlined as well.
type Logger struct {
log *logr.Logger
}
// NewLogger creates a new Logger instance which can be configured via `(*Logger).Configure`.
func NewLogger(options ...Option) *Logger {
options = append(options, logr.StackFilter(GetPackageName(mlogPkg)))
lgr, _ := logr.New(options...)
log := lgr.NewLogger()
return &Logger{
log: &log,
}
}
// Configure provides a new configuration for this logger.
// Zero or more sources of config can be provided:
// cfgFile - path to file containing JSON
// cfgEscaped - JSON string probably from ENV var
//
// For each case JSON containing log targets is provided. Target name collisions are resolved
// using the following precedence:
// cfgFile > cfgEscaped
func (l *Logger) Configure(cfgFile string, cfgEscaped string) error {
cfgMap := make(LoggerConfig)
// Add config from file
if cfgFile != "" {
b, err := ioutil.ReadFile(cfgFile)
if err != nil {
return fmt.Errorf("error reading logger config file %s: %w", cfgFile, err)
}
var mapCfgFile LoggerConfig
if err := json.Unmarshal(b, &mapCfgFile); err != nil {
return fmt.Errorf("error decoding logger config file %s: %w", cfgFile, err)
}
cfgMap.append(mapCfgFile)
}
// Add config from escaped json string
if cfgEscaped != "" {
var mapCfgEscaped LoggerConfig
if err := json.Unmarshal([]byte(cfgEscaped), &mapCfgEscaped); err != nil {
return fmt.Errorf("error decoding logger config as escaped json: %w", err)
}
cfgMap.append(mapCfgEscaped)
}
if len(cfgMap) == 0 {
return nil
}
return logrcfg.ConfigureTargets(l.log.Logr(), cfgMap, nil)
}
// With creates a new Logger with the specified fields. This is a light-weight
// operation and can be called on demand.
func (l *Logger) With(fields ...Field) *Logger {
logWith := l.log.With(fields...)
return &Logger{
log: &logWith,
}
}
// IsLevelEnabled returns true only if at least one log target is
// configured to emit the specified log level. Use this check when
// gathering the log info may be expensive.
//
// Note, transformations and serializations done via fields are already
// lazily evaluated and don't require this check beforehand.
func (l *Logger) IsLevelEnabled(level Level) bool {
return l.log.IsLevelEnabled(level)
}
// Log emits the log record for any targets configured for the specified level.
func (l *Logger) Log(level Level, msg string, fields ...Field) {
l.log.Log(level, msg, fields...)
}
// LogM emits the log record for any targets configured for the specified levels.
// Equivalent to calling `Log` once for each level.
func (l *Logger) LogM(levels []Level, msg string, fields ...Field) {
l.log.LogM(levels, msg, fields...)
}
// Convenience method equivalent to calling `Log` with the `Trace` level.
func (l *Logger) Trace(msg string, fields ...Field) {
l.log.Trace(msg, fields...)
}
// Convenience method equivalent to calling `Log` with the `Debug` level.
func (l *Logger) Debug(msg string, fields ...Field) {
l.log.Debug(msg, fields...)
}
// Convenience method equivalent to calling `Log` with the `Info` level.
func (l *Logger) Info(msg string, fields ...Field) {
l.log.Info(msg, fields...)
}
// Convenience method equivalent to calling `Log` with the `Warn` level.
func (l *Logger) Warn(msg string, fields ...Field) {
l.log.Warn(msg, fields...)
}
// Convenience method equivalent to calling `Log` with the `Error` level.
func (l *Logger) Error(msg string, fields ...Field) {
l.log.Error(msg, fields...)
}
// Convenience method equivalent to calling `Log` with the `Fatal` level,
// followed by `os.Exit(1)`.
func (l *Logger) Fatal(msg string, fields ...Field) {
l.log.Log(logr.Fatal, msg, fields...)
_ = l.Shutdown()
os.Exit(1)
}
// HasTargets returns true if at least one log target has been added.
func (l *Logger) HasTargets() bool {
return l.log.Logr().HasTargets()
}
// StdLogger creates a standard logger backed by this logger.
// All log records are output with the specified level.
func (l *Logger) StdLogger(level Level) *log.Logger {
return l.log.StdLogger(level)
}
// RedirectStdLog redirects output from the standard library's package-global logger
// to this logger at the specified level and with zero or more Field's. Since this logger already
// handles caller annotations, timestamps, etc., it automatically disables the standard
// library's annotations and prefixing.
// A function is returned that restores the original prefix and flags and resets the standard
// library's output to os.Stdout.
func (l *Logger) RedirectStdLog(level Level, fields ...Field) func() {
return l.log.Logr().RedirectStdLog(level, fields...)
}
// Shutdown shuts down the logger after making best efforts to flush any
// remaining records.
func (l *Logger) Shutdown() error {
ctx, cancel := context.WithTimeout(context.Background(), ShutdownTimeout)
defer cancel()
return l.log.Logr().ShutdownWithTimeout(ctx)
}
// GetPackageName reduces a fully qualified function name to the package name
// By sirupsen: https://github.com/sirupsen/logrus/blob/master/entry.go
func GetPackageName(f string) string {
for {
lastPeriod := strings.LastIndex(f, ".")
lastSlash := strings.LastIndex(f, "/")
if lastPeriod > lastSlash {
f = f[:lastPeriod]
} else {
break
}
}
return f
}