restore v 0.2.0

2021-09-19 16:50:42 +03:00
commit f9ae79614a
16 changed files with 1018 additions and 0 deletions
--- a/.drone.yml
+++ b/.drone.yml
@@ -0,0 +1,50 @@
+kind: pipeline
+name: default
+
+steps:
+- name: test 
+  image: golang:1.14.2
+  volumes:
+  - name: deps
+    path: /go/src/mod
+  commands:
+  - go test 
+
+- name: golangci-lint
+  image: golangci/golangci-lint:v1.29
+  commands:
+  - golangci-lint run
+
+- name: logrus golangci-lint
+  image: golangci/golangci-lint:v1.29
+  commands:
+  - cd logrus
+  - golangci-lint run
+
+- name: logrus test
+  image: golang:1.14.2
+  volumes:
+    - name: deps
+      path: /go/src/mod
+  commands:
+  - cd logrus
+  - go test 
+
+- name: zap golangci-lint
+  image: golangci/golangci-lint:v1.29
+  commands:
+  - cd zap
+  - golangci-lint run
+
+- name: zap test
+  image: golang:1.14.2
+  volumes:
+    - name: deps
+      path: /go/src/mod
+  commands:
+  - cd zap
+  - go test
+
+volumes:
+- name: deps
+  temp: {}
--- a/.gitignore
+++ b/.gitignore
@@ -0,0 +1,17 @@
+# ---> Go
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
+
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -0,0 +1,33 @@
+linters-settings:
+    dupl:
+      threshold: 100
+    funlen:
+      lines: 100
+      statements: 50
+    goconst:
+      min-len: 2
+      min-occurrences: 2
+    gocyclo:
+      min-complexity: 15
+    golint:
+      min-confidence: 0
+    govet:
+      check-shadowing: true
+    lll:
+      line-length: 140
+    maligned:
+      suggest-new: true
+    misspell:
+      locale: US  
+    exhaustive:
+      default-signifies-exhaustive: true
+
+linters:
+    enable-all: true
+
+issues:
+  # Excluding configuration per-path, per-linter, per-text and per-source
+  exclude-rules:
+    - path: _test\.go
+      linters:
+        - gomnd
--- a/19
+++ b/19
@@ -0,0 +1,19 @@
+MIT License Copyright (c) 2020 go-4devs
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is furnished
+to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice (including the next
+paragraph) shall be included in all copies or substantial portions of the
+Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
+OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
--- a/README.md
+++ b/README.md
@@ -0,0 +1,5 @@
+# log
+
+[![Build Status](https://drone.gitoa.ru/api/badges/go-4devs/log/status.svg)](https://drone.gitoa.ru/go-4devs/log)
+[![Go Report Card](https://goreportcard.com/badge/gitoa.ru/go-4devs/log)](https://goreportcard.com/report/gitoa.ru/go-4devs/log)
+[![GoDoc](https://godoc.org/gitoa.ru/go-4devs/log?status.svg)](http://godoc.org/gitoa.ru/go-4devs/log)
--- a/doc.go
+++ b/doc.go
@@ -0,0 +1,4 @@
+/*
+Package log logged data by handler and use processor, exposes eight methods to write logs to the eight RFC 5424 levels.
+*/
+package log
--- a/field.go
+++ b/field.go
@@ -0,0 +1,40 @@
+package log
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Fields slice field.
+type Fields []Field
+
+// String implement stringer.
+func (f Fields) String() string {
+	str := make([]string, len(f))
+	for i, field := range f {
+		str[i] = field.String()
+	}
+
+	return strings.Join(str, " ")
+}
+
+// NewField create field.
+func NewField(key string, value interface{}) Field {
+	return Field{Key: key, Value: value}
+}
+
+// Field struct.
+type Field struct {
+	Key   string
+	Value interface{}
+}
+
+// String implent stringer.
+func (f Field) String() string {
+	return fmt.Sprintf("%s=%+v", f.Key, f.Value)
+}
+
+// FieldError new errors field with key error.
+func FieldError(err error) Field {
+	return NewField("error", err)
+}
--- a/global.go
+++ b/global.go
@@ -0,0 +1,183 @@
+package log
+
+import (
+	"context"
+)
+
+//nolint:gochecknoglobals
+var global = With(New(), WithLevel(LevelDebug))
+
+// SetLogger sets global used logger. This function is not thread-safe.
+func SetLogger(l Logger) {
+	global = l
+}
+
+// GetLogger return global logger.
+func GetLogger() Logger {
+	return global
+}
+
+// Emerg log by emergency level.
+func Emerg(ctx context.Context, args ...interface{}) {
+	global.Emerg(ctx, args...)
+}
+
+// Alert log by alert level.
+func Alert(ctx context.Context, args ...interface{}) {
+	global.Alert(ctx, args...)
+}
+
+// Crit log by critical level.
+func Crit(ctx context.Context, args ...interface{}) {
+	global.Crit(ctx, args...)
+}
+
+// Err log by error level.
+func Err(ctx context.Context, args ...interface{}) {
+	global.Err(ctx, args...)
+}
+
+// Warn logs by warning level.
+func Warn(ctx context.Context, args ...interface{}) {
+	global.Warn(ctx, args...)
+}
+
+// Notice log by notice level.
+func Notice(ctx context.Context, args ...interface{}) {
+	global.Notice(ctx, args...)
+}
+
+// Info log by info level.
+func Info(ctx context.Context, args ...interface{}) {
+	global.Info(ctx, args...)
+}
+
+// Debug log by debug level.
+func Debug(ctx context.Context, args ...interface{}) {
+	global.Debug(ctx, args...)
+}
+
+// Print log by info level and arguments.
+func Print(args ...interface{}) {
+	global.Print(args...)
+}
+
+// Fatal log by alert level and arguments.
+func Fatal(args ...interface{}) {
+	global.Fatal(args...)
+}
+
+// Panic log by emergency level and arguments.
+func Panic(args ...interface{}) {
+	global.Panic(args...)
+}
+
+// Println log by info level and arguments.
+func Println(args ...interface{}) {
+	global.Println(args...)
+}
+
+// Fatalln log by alert level and arguments.
+func Fatalln(args ...interface{}) {
+	global.Fatalln(args...)
+}
+
+// Panicln log by emergency level and arguments.
+func Panicln(args ...interface{}) {
+	global.Panicln(args...)
+}
+
+// EmergKV log by emergency level and key-values.
+func EmergKV(ctx context.Context, msg string, args ...interface{}) {
+	global.EmergKV(ctx, msg, args...)
+}
+
+// AlertKV log by alert level and key-values.
+func AlertKV(ctx context.Context, msg string, args ...interface{}) {
+	global.AlertKV(ctx, msg, args...)
+}
+
+// CritKV log by critcal level and key-values.
+func CritKV(ctx context.Context, msg string, args ...interface{}) {
+	global.CritKV(ctx, msg, args...)
+}
+
+// ErrKV log by error level and key-values.
+func ErrKV(ctx context.Context, msg string, args ...interface{}) {
+	global.ErrKV(ctx, msg, args...)
+}
+
+// WarnKV log by warning level and key-values.
+func WarnKV(ctx context.Context, msg string, args ...interface{}) {
+	global.WarnKV(ctx, msg, args...)
+}
+
+// NoticeKV log by notice level and key-values.
+func NoticeKV(ctx context.Context, msg string, args ...interface{}) {
+	global.NoticeKV(ctx, msg, args...)
+}
+
+// InfoKV log by info level and key-values.
+func InfoKV(ctx context.Context, msg string, args ...interface{}) {
+	global.InfoKV(ctx, msg, args...)
+}
+
+// DebugKV log by debug level and key-values.
+func DebugKV(ctx context.Context, msg string, args ...interface{}) {
+	global.DebugKV(ctx, msg, args...)
+}
+
+// Emergf log by emergency level by format and arguments.
+func Emergf(ctx context.Context, format string, args ...interface{}) {
+	global.Emergf(ctx, format, args...)
+}
+
+// Alertf log by alert level by format and arguments.
+func Alertf(ctx context.Context, format string, args ...interface{}) {
+	global.Alertf(ctx, format, args...)
+}
+
+// Critf log by critical level by format and arguments.
+func Critf(ctx context.Context, format string, args ...interface{}) {
+	global.Critf(ctx, format, args...)
+}
+
+// Errf log by error level by format and arguments.
+func Errf(ctx context.Context, format string, args ...interface{}) {
+	global.Errf(ctx, format, args...)
+}
+
+// Warnf log by warning level by format and arguments.
+func Warnf(ctx context.Context, format string, args ...interface{}) {
+	global.Warnf(ctx, format, args...)
+}
+
+// Noticef log by notice level by format and arguments.
+func Noticef(ctx context.Context, format string, args ...interface{}) {
+	global.Noticef(ctx, format, args...)
+}
+
+// Infof log by info level by format and arguments.
+func Infof(ctx context.Context, format string, args ...interface{}) {
+	global.Noticef(ctx, format, args...)
+}
+
+// Debugf log by debug level by format and arguments.
+func Debugf(ctx context.Context, format string, args ...interface{}) {
+	global.Debugf(ctx, format, args...)
+}
+
+// Printf log by info level by format and arguments without context.
+func Printf(format string, args ...interface{}) {
+	global.Printf(format, args...)
+}
+
+// Fatalf log by alert level by format and arguments without context.
+func Fatalf(format string, args ...interface{}) {
+	global.Fatalf(format, args...)
+}
+
+// Panicf log by emergency level and arguments without context.
+func Panicf(format string, args ...interface{}) {
+	global.Panicf(format, args...)
+}
--- a/go.mod
+++ b/go.mod
@@ -0,0 +1,3 @@
+module gitoa.ru/go-4devs/log
+
+go 1.14
--- a/level.go
+++ b/level.go
@@ -0,0 +1,22 @@
+package log
+
+//go:generate stringer -type=Level -linecomment
+
+// Level log.
+type Level uint8
+
+// awailable log levels.
+const (
+	LevelEmergency Level = iota // emergency
+	LevelAlert                  // alert
+	LevelCritical               // critical
+	LevelError                  // error
+	LevelWarning                // warning
+	LevelNotice                 // notice
+	LevelInfo                   // info
+	LevelDebug                  // debug
+)
+
+func (l Level) MarshalJSON() ([]byte, error) {
+	return []byte("\"" + l.String() + "\""), nil
+}
--- a/level_string.go
+++ b/level_string.go
@@ -0,0 +1,30 @@
+// Code generated by "stringer -type=Level -linecomment"; DO NOT EDIT.
+
+package log
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[LevelEmergency-0]
+	_ = x[LevelAlert-1]
+	_ = x[LevelCritical-2]
+	_ = x[LevelError-3]
+	_ = x[LevelWarning-4]
+	_ = x[LevelNotice-5]
+	_ = x[LevelInfo-6]
+	_ = x[LevelDebug-7]
+}
+
+const _Level_name = "emergencyalertcriticalerrorwarningnoticeinfodebug"
+
+var _Level_index = [...]uint8{0, 9, 14, 22, 27, 34, 40, 44, 49}
+
+func (i Level) String() string {
+	if i >= Level(len(_Level_index)-1) {
+		return "Level(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _Level_name[_Level_index[i]:_Level_index[i+1]]
+}
--- a/logger.go
+++ b/logger.go
@@ -0,0 +1,223 @@
+package log
+
+import (
+	"context"
+	"fmt"
+)
+
+// Logger logged message.
+type Logger func(ctx context.Context, level Level, msg string, fields Fields)
+
+func (l Logger) log(ctx context.Context, level Level, args ...interface{}) {
+	l(ctx, level, fmt.Sprint(args...), nil)
+}
+
+func (l Logger) logKV(ctx context.Context, level Level, msg string, args ...interface{}) {
+	l(ctx, level, msg, l.kv(ctx, args...))
+}
+
+func (l Logger) logf(ctx context.Context, level Level, format string, args ...interface{}) {
+	l(ctx, level, fmt.Sprintf(format, args...), nil)
+}
+
+func (l Logger) logln(ctx context.Context, level Level, args ...interface{}) {
+	l(ctx, level, fmt.Sprintln(args...), nil)
+}
+
+func (l Logger) kv(ctx context.Context, args ...interface{}) []Field {
+	fields := make([]Field, 0, len(args))
+
+	for i := 0; i < len(args); i++ {
+		if f, ok := args[i].(Field); ok {
+			fields = append(fields, f)
+			continue
+		}
+
+		if i == len(args)-1 {
+			l(ctx, LevelCritical, fmt.Sprint("Ignored key without a value.", args[i]), fields)
+			break
+		}
+
+		i++
+
+		key, val := args[i-1], args[i]
+		if keyStr, ok := key.(string); ok {
+			fields = append(fields, Field{Key: keyStr, Value: val})
+			continue
+		}
+
+		l(ctx, LevelCritical, fmt.Sprint("Ignored key-value pairs with non-string keys.", key, val), fields)
+	}
+
+	return fields
+}
+
+// With adds middlewares to logger.
+func (l Logger) With(mw ...Middleware) Logger {
+	return With(l, mw...)
+}
+
+// Emerg log by emergency level.
+func (l Logger) Emerg(ctx context.Context, args ...interface{}) {
+	l.log(ctx, LevelEmergency, args...)
+}
+
+// Alert log by alert level.
+func (l Logger) Alert(ctx context.Context, args ...interface{}) {
+	l.log(ctx, LevelAlert, args...)
+}
+
+// Crit log by critical level.
+func (l Logger) Crit(ctx context.Context, args ...interface{}) {
+	l.log(ctx, LevelCritical, args...)
+}
+
+// Err log by error level.
+func (l Logger) Err(ctx context.Context, args ...interface{}) {
+	l.log(ctx, LevelError, args...)
+}
+
+// Warn log by warning level.
+func (l Logger) Warn(ctx context.Context, args ...interface{}) {
+	l.log(ctx, LevelWarning, args...)
+}
+
+// Notice log by notice level.
+func (l Logger) Notice(ctx context.Context, args ...interface{}) {
+	l.log(ctx, LevelNotice, args...)
+}
+
+// Info log by info level.
+func (l Logger) Info(ctx context.Context, args ...interface{}) {
+	l.log(ctx, LevelInfo, args...)
+}
+
+// Debug log by debug level.
+func (l Logger) Debug(ctx context.Context, args ...interface{}) {
+	l.log(ctx, LevelDebug, args...)
+}
+
+// Print log by info level and arguments.
+func (l Logger) Print(args ...interface{}) {
+	l.log(context.Background(), LevelInfo, args...)
+}
+
+// Fatal log by alert level and arguments.
+func (l Logger) Fatal(args ...interface{}) {
+	l.log(context.Background(), LevelAlert, args...)
+}
+
+// Panic log by emergency level and arguments.
+func (l Logger) Panic(args ...interface{}) {
+	l.log(context.Background(), LevelEmergency, args...)
+}
+
+// Println log by info level and arguments.
+func (l Logger) Println(args ...interface{}) {
+	l.logln(context.Background(), LevelInfo, args...)
+}
+
+// Fatalln log by alert level and arguments.
+func (l Logger) Fatalln(args ...interface{}) {
+	l.logln(context.Background(), LevelAlert, args...)
+}
+
+// Panicln log by emergency level and arguments.
+func (l Logger) Panicln(args ...interface{}) {
+	l.logln(context.Background(), LevelEmergency, args...)
+}
+
+// EmergKV log by emergency level and key-values.
+func (l Logger) EmergKV(ctx context.Context, msg string, args ...interface{}) {
+	l.logKV(ctx, LevelEmergency, msg, args...)
+}
+
+// AlertKV log by alert level and key-values.
+func (l Logger) AlertKV(ctx context.Context, msg string, args ...interface{}) {
+	l.logKV(ctx, LevelAlert, msg, args...)
+}
+
+// CritKV log by critcal level and key-values.
+func (l Logger) CritKV(ctx context.Context, msg string, args ...interface{}) {
+	l.logKV(ctx, LevelCritical, msg, args...)
+}
+
+// ErrKV log by error level and key-values.
+func (l Logger) ErrKV(ctx context.Context, msg string, args ...interface{}) {
+	l.logKV(ctx, LevelError, msg, args...)
+}
+
+// WarnKV log by warning level and key-values.
+func (l Logger) WarnKV(ctx context.Context, msg string, args ...interface{}) {
+	l.logKV(ctx, LevelWarning, msg, args...)
+}
+
+// NoticeKV log by notice level and key-values.
+func (l Logger) NoticeKV(ctx context.Context, msg string, args ...interface{}) {
+	l.logKV(ctx, LevelNotice, msg, args...)
+}
+
+// InfoKV log by info level and key-values.
+func (l Logger) InfoKV(ctx context.Context, msg string, args ...interface{}) {
+	l.logKV(ctx, LevelInfo, msg, args...)
+}
+
+// DebugKV log by debug level and key-values.
+func (l Logger) DebugKV(ctx context.Context, msg string, args ...interface{}) {
+	l.logKV(ctx, LevelDebug, msg, args...)
+}
+
+// Emergf log by emergency level by format and arguments.
+func (l Logger) Emergf(ctx context.Context, format string, args ...interface{}) {
+	l.logf(ctx, LevelEmergency, format, args...)
+}
+
+// Alertf log by alert level by format and arguments.
+func (l Logger) Alertf(ctx context.Context, format string, args ...interface{}) {
+	l.logf(ctx, LevelAlert, format, args...)
+}
+
+// Critf log by critical level by format and arguments.
+func (l Logger) Critf(ctx context.Context, format string, args ...interface{}) {
+	l.logf(ctx, LevelCritical, format, args...)
+}
+
+// Errf log by error level by format and arguments.
+func (l Logger) Errf(ctx context.Context, format string, args ...interface{}) {
+	l.logf(ctx, LevelError, format, args...)
+}
+
+// Warnf log by warning level by format and arguments.
+func (l Logger) Warnf(ctx context.Context, format string, args ...interface{}) {
+	l.logf(ctx, LevelWarning, format, args...)
+}
+
+// Noticef log by notice level by format and arguments.
+func (l Logger) Noticef(ctx context.Context, format string, args ...interface{}) {
+	l.logf(ctx, LevelNotice, format, args...)
+}
+
+// Infof log by info level by format and arguments.
+func (l Logger) Infof(ctx context.Context, format string, args ...interface{}) {
+	l.logf(ctx, LevelInfo, format, args...)
+}
+
+// Debugf log by debug level by format and arguments.
+func (l Logger) Debugf(ctx context.Context, format string, args ...interface{}) {
+	l.logf(ctx, LevelDebug, format, args...)
+}
+
+// Printf log by info level by format and arguments without context.
+func (l Logger) Printf(format string, args ...interface{}) {
+	l.logf(context.Background(), LevelInfo, format, args...)
+}
+
+// Fatalf log by alert level by format and arguments without context.
+func (l Logger) Fatalf(format string, args ...interface{}) {
+	l.logf(context.Background(), LevelAlert, format, args...)
+}
+
+// Panicf log by emergency level and arguments without context.
+func (l Logger) Panicf(format string, args ...interface{}) {
+	l.logf(context.Background(), LevelEmergency, format, args...)
+}
--- a/logger_example_test.go
+++ b/logger_example_test.go
@@ -0,0 +1,126 @@
+package log_test
+
+import (
+	"context"
+	"fmt"
+	std "log"
+	"os"
+
+	"gitoa.ru/go-4devs/log"
+)
+
+//nolint:gochecknoglobals
+var ctx = context.Background()
+
+func ExampleNew() {
+	logger := log.New(log.WithStdout())
+	logger.Info(ctx, "same message")
+	// Output: msg="same message"
+}
+
+func ExampleInfo() {
+	std.SetOutput(os.Stdout)
+	std.SetFlags(0)
+	log.Info(ctx, "same message")
+	// Output: msg="same message" level=info
+}
+
+func ExampleErrKV() {
+	std.SetOutput(os.Stdout)
+	std.SetFlags(0)
+	log.ErrKV(ctx, "same message", "key", "addition value")
+	// Output: msg="same message" key=addition value level=error
+}
+
+func ExampleNew_errf() {
+	logger := log.New(log.WithStdout())
+	logger.Errf(ctx, "same message %d", 1)
+	// Output: msg="same message 1"
+}
+
+func ExampleNew_debugKV() {
+	logger := log.New(log.WithStdout()).With(log.WithLevel(log.LevelDebug))
+	logger.DebugKV(ctx, "same message", "error", os.ErrNotExist)
+	// Output: msg="same message" error=file does not exist level=debug
+}
+
+func ExampleNew_level() {
+	logger := log.New(log.WithStdout()).With(log.WithLevel(log.LevelError))
+	logger.Info(ctx, "same message")
+	// Output:
+
+	logger.Err(ctx, "same error message")
+	// Output: msg="same error message" level=error
+}
+
+func ExampleNew_jsonFormat() {
+	logger := log.New(log.WithStdout(), log.WithJSONFormat()).
+		With(
+			log.WithCaller(4, true),
+			log.WithLevel(log.LevelDebug),
+			log.GoVersion("go-version"),
+		)
+	logger.Err(ctx, "same error message")
+	// Output: {"caller":"logger_example_test.go:63","go-version":"go1.14.2","level":"error","msg":"same error message"}
+}
+
+func ExampleNew_withLogger() {
+	stdlogger := std.New(os.Stdout, "same prefix ", std.Lshortfile)
+	logger := log.With(
+		log.New(
+			log.WithLogger(
+				stdlogger,
+				func(msg string, fields log.Fields) string {
+					return fmt.Sprint("msg=\"", msg, "\" ", fields)
+				},
+			),
+			log.WithCalldepth(9),
+		),
+		log.WithLevel(log.LevelDebug),
+		log.GoVersion("go-version"),
+	)
+	logger.Err(ctx, "same error message")
+	logger.InfoKV(ctx, "same info message", "api-version", 0.1)
+
+	// Output:
+	// same prefix logger_example_test.go:82: msg="same error message" level=error go-version=go1.14.2
+	// same prefix logger_example_test.go:83: msg="same info message" api-version=0.1 level=info go-version=go1.14.2
+}
+
+type ctxKey string
+
+func (c ctxKey) String() string {
+	return string(c)
+}
+
+func levelInfo(ctx context.Context, level log.Level, msg string, fields log.Fields, handler log.Logger) {
+	handler(ctx, level, msg, append(fields, log.Field{Key: "level", Value: level}))
+}
+
+func ExampleWith() {
+	var requestID ctxKey = "requestID"
+	vctx := context.WithValue(ctx, requestID, "6a5fa048-7181-11ea-bc55-0242ac130003")
+
+	logger := log.With(
+		log.New(log.WithStdout()),
+		levelInfo, log.WithContextValue(requestID), log.KeyValue("api", "0.1.0"), log.GoVersion("go"),
+	)
+	logger.Info(vctx, "same message")
+	// Output: msg="same message" level=info requestID=6a5fa048-7181-11ea-bc55-0242ac130003 api=0.1.0 go=go1.14.2
+}
+
+func ExampleLogger_Print() {
+	logger := log.With(
+		log.New(log.WithStdout()),
+		levelInfo, log.KeyValue("client", "http"), log.KeyValue("api", "0.1.0"), log.GoVersion("go"),
+	)
+	logger.Print("same message")
+	// Output: msg="same message" level=info client=http api=0.1.0 go=go1.14.2
+}
+
+func ExamplePrint() {
+	std.SetOutput(os.Stdout)
+	std.SetFlags(0)
+	log.Print("same message")
+	// Output: msg="same message" level=info
+}
--- a/logger_test.go
+++ b/logger_test.go
@@ -0,0 +1,31 @@
+package log_test
+
+import (
+	"bytes"
+	"context"
+	"os"
+	"testing"
+
+	"gitoa.ru/go-4devs/log"
+)
+
+func TestFields(t *testing.T) {
+	type rObj struct {
+		id string
+	}
+
+	ctx := context.Background()
+	buf := &bytes.Buffer{}
+	log := log.New(log.WithWriter(buf))
+	success := "msg=\"message\" err=file already exists version=0.1.0 obj={id:uid}\n"
+
+	log.InfoKV(ctx, "message",
+		"err", os.ErrExist,
+		"version", "0.1.0",
+		"obj", rObj{id: "uid"},
+	)
+
+	if success != buf.String() {
+		t.Errorf("invalid value\n got:%s\n exp:%s", buf, success)
+	}
+}
--- a/middleware.go
+++ b/middleware.go
@@ -0,0 +1,111 @@
+package log
+
+import (
+	"context"
+	"fmt"
+	"path/filepath"
+	"runtime"
+	"time"
+)
+
+// Middleware handle.
+type Middleware func(ctx context.Context, level Level, msg string, fields Fields, handler Logger)
+
+// With add middleware to logger.
+func With(logger Logger, mw ...Middleware) Logger {
+	switch len(mw) {
+	case 0:
+		return logger
+	case 1:
+		return func(ctx context.Context, level Level, msg string, fields Fields) {
+			mw[0](ctx, level, msg, fields, logger)
+		}
+	}
+
+	lastI := len(mw) - 1
+
+	return func(ctx context.Context, level Level, msg string, fields Fields) {
+		var (
+			chainHandler func(ctx context.Context, level Level, msg string, fields Fields)
+			curI         int
+		)
+
+		chainHandler = func(currentCtx context.Context, currentLevel Level, currentMsg string, currentFields Fields) {
+			if curI == lastI {
+				logger(currentCtx, currentLevel, currentMsg, currentFields)
+				return
+			}
+			curI++
+			mw[curI](currentCtx, currentLevel, currentMsg, currentFields, chainHandler)
+			curI--
+		}
+
+		mw[0](ctx, level, msg, fields, chainHandler)
+	}
+}
+
+// WithLevel sets log level.
+func WithLevel(lvl Level) Middleware {
+	return func(ctx context.Context, level Level, msg string, fields Fields, handler Logger) {
+		if level <= lvl {
+			handler(ctx, level, msg, append(fields, Field{Key: "level", Value: level}))
+		}
+	}
+}
+
+// KeyValue add field by const key value.
+func KeyValue(key string, value interface{}) Middleware {
+	return func(ctx context.Context, level Level, msg string, fields Fields, handler Logger) {
+		handler(ctx, level, msg, append(fields, Field{Key: key, Value: value}))
+	}
+}
+
+// GoVersion add field by go version.
+func GoVersion(key string) Middleware {
+	return func(ctx context.Context, level Level, msg string, fields Fields, handler Logger) {
+		handler(ctx, level, msg, append(fields, Field{Key: key, Value: runtime.Version()}))
+	}
+}
+
+// WithContext add field by context key.
+func WithContextValue(keys ...fmt.Stringer) Middleware {
+	return func(ctx context.Context, level Level, msg string, fields Fields, handler Logger) {
+		ctxFields := make(Fields, len(keys))
+		for i, key := range keys {
+			ctxFields[i] = Field{Key: key.String(), Value: ctx.Value(key)}
+		}
+
+		handler(ctx, level, msg, append(fields, ctxFields...))
+	}
+}
+
+// WithCaller adds called file.
+func WithCaller(calldepth int, short bool) Middleware {
+	return func(ctx context.Context, level Level, msg string, fields Fields, handler Logger) {
+		_, file, line, ok := runtime.Caller(calldepth)
+		if !ok {
+			file, line = "???", 0
+		}
+
+		if short && ok {
+			file = filepath.Base(file)
+		}
+
+		handler(ctx, level, msg, append(fields, NewField("caller", fmt.Sprint(file, ":", line))))
+	}
+}
+
+// WithTime adds time.
+func WithTime(format string) Middleware {
+	return func(ctx context.Context, level Level, msg string, fields Fields, handler Logger) {
+		handler(ctx, level, msg, append(fields, NewField("time", time.Now().Format(format))))
+	}
+}
+
+// WithMetrics adds handle metrics.
+func WithMetrics(metrics func(level Level)) Middleware {
+	return func(ctx context.Context, level Level, msg string, fields Fields, handler Logger) {
+		go metrics(level)
+		handler(ctx, level, msg, fields)
+	}
+}
--- a/std.go
+++ b/std.go
@@ -0,0 +1,121 @@
+package log
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"os"
+)
+
+const (
+	calldepth = 3
+)
+
+// New creates standart logger.
+func New(opts ...Option) Logger {
+	logger := logger{
+		format:    stringFormat,
+		output:    log.Output,
+		calldepth: calldepth,
+	}
+
+	for _, opt := range opts {
+		opt(&logger)
+	}
+
+	return func(ctx context.Context, level Level, msg string, fields Fields) {
+		_ = logger.output(logger.calldepth, logger.format(msg, fields))
+
+		switch level {
+		case LevelEmergency:
+			panic(msg)
+		case LevelAlert:
+			os.Exit(1)
+		default:
+		}
+	}
+}
+
+// Option configure log.
+type Option func(*logger)
+
+// Format sets formats output message.
+type Format func(msg string, fields Fields) string
+
+type logger struct {
+	output    func(calldepth int, s string) error
+	format    Format
+	calldepth int
+}
+
+// WithWriter sets writer logger.
+func WithWriter(writer io.Writer) Option {
+	return func(l *logger) {
+		l.output = log.New(writer, "", 0).Output
+	}
+}
+
+// WithStdout sets logged to os.Stdout.
+func WithStdout() Option {
+	return func(l *logger) {
+		l.output = log.New(os.Stdout, "", 0).Output
+	}
+}
+
+// WithFormat sets format log.
+func WithFormat(format Format) Option {
+	return func(l *logger) {
+		l.format = format
+	}
+}
+
+// WithStringFormat sets format as simple string.
+func WithStringFormat() Option {
+	return func(l *logger) {
+		l.format = stringFormat
+	}
+}
+
+// WithJSONFormat sets json output format.
+func WithJSONFormat() Option {
+	return func(l *logger) {
+		l.format = jsonFormat
+	}
+}
+
+// WithCalldepth sets depth filename.
+func WithCalldepth(calldepth int) Option {
+	return func(l *logger) {
+		l.calldepth = calldepth
+	}
+}
+
+// WithLogger sets logger anf format.
+func WithLogger(std *log.Logger, format Format) Option {
+	return func(l *logger) {
+		l.output = std.Output
+		l.format = format
+	}
+}
+
+func stringFormat(msg string, fields Fields) string {
+	return fmt.Sprint("msg=\"", msg, "\" ", fields)
+}
+
+func jsonFormat(msg string, fields Fields) string {
+	data := make(map[string]interface{}, len(fields)+1)
+	data["msg"] = msg
+
+	for _, field := range fields {
+		data[field.Key] = field.Value
+	}
+
+	res, err := json.Marshal(data)
+	if err != nil {
+		return stringFormat(msg, append(fields, FieldError(err)))
+	}
+
+	return string(res)
+}