forgejo/modules/log/logger.go
wxiaoguang 4647660776
Rewrite logger system (#24726)
## ⚠️ Breaking

The `log.<mode>.<logger>` style config has been dropped. If you used it,
please check the new config manual & app.example.ini to make your
instance output logs as expected.

Although many legacy options still work, it's encouraged to upgrade to
the new options.

The SMTP logger is deleted because SMTP is not suitable to collect logs.

If you have manually configured Gitea log options, please confirm the
logger system works as expected after upgrading.

## Description

Close #12082 and maybe more log-related issues, resolve some related
FIXMEs in old code (which seems unfixable before)

Just like rewriting queue #24505 : make code maintainable, clear legacy
bugs, and add the ability to support more writers (eg: JSON, structured
log)

There is a new document (with examples): `logging-config.en-us.md`

This PR is safer than the queue rewriting, because it's just for
logging, it won't break other logic.

## The old problems

The logging system is quite old and difficult to maintain:
* Unclear concepts: Logger, NamedLogger, MultiChannelledLogger,
SubLogger, EventLogger, WriterLogger etc
* Some code is diffuclt to konw whether it is right:
`log.DelNamedLogger("console")` vs `log.DelNamedLogger(log.DEFAULT)` vs
`log.DelLogger("console")`
* The old system heavily depends on ini config system, it's difficult to
create new logger for different purpose, and it's very fragile.
* The "color" trick is difficult to use and read, many colors are
unnecessary, and in the future structured log could help
* It's difficult to add other log formats, eg: JSON format
* The log outputer doesn't have full control of its goroutine, it's
difficult to make outputer have advanced behaviors
* The logs could be lost in some cases: eg: no Fatal error when using
CLI.
* Config options are passed by JSON, which is quite fragile.
* INI package makes the KEY in `[log]` section visible in `[log.sub1]`
and `[log.sub1.subA]`, this behavior is quite fragile and would cause
more unclear problems, and there is no strong requirement to support
`log.<mode>.<logger>` syntax.


## The new design

See `logger.go` for documents.


## Screenshot

<details>


![image](https://github.com/go-gitea/gitea/assets/2114189/4462d713-ba39-41f5-bb08-de912e67e1ff)


![image](https://github.com/go-gitea/gitea/assets/2114189/b188035e-f691-428b-8b2d-ff7b2199b2f9)


![image](https://github.com/go-gitea/gitea/assets/2114189/132e9745-1c3b-4e00-9e0d-15eaea495dee)

</details>

## TODO

* [x] add some new tests
* [x] fix some tests
* [x] test some sub-commands (manually ....)

---------

Co-authored-by: Jason Song <i@wolfogre.com>
Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: Giteabot <teabot@gitea.io>
2023-05-21 22:35:11 +00:00

51 lines
1.7 KiB
Go

// Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
// Package log provides logging capabilities for Gitea.
// Concepts:
//
// * Logger: a Logger provides logging functions and dispatches log events to all its writers
//
// * EventWriter: written log Event to a destination (eg: file, console)
// - EventWriterBase: the base struct of a writer, it contains common fields and functions for all writers
// - WriterType: the type name of a writer, eg: console, file
// - WriterName: aka Mode Name in document, the name of a writer instance, it's usually defined by the config file.
// It is called "mode name" because old code use MODE as config key, to keep compatibility, keep this concept.
//
// * WriterMode: the common options for all writers, eg: log level.
// - WriterConsoleOption and others: the specified options for a writer, eg: file path, remote address.
//
// Call graph:
// -> log.Info()
// -> LoggerImpl.Log()
// -> LoggerImpl.SendLogEvent, then the event goes into writer's goroutines
// -> EventWriter.Run() handles the events
package log
// BaseLogger provides the basic logging functions
type BaseLogger interface {
Log(skip int, level Level, format string, v ...any)
GetLevel() Level
}
// LevelLogger provides level-related logging functions
type LevelLogger interface {
LevelEnabled(level Level) bool
Trace(format string, v ...any)
Debug(format string, v ...any)
Info(format string, v ...any)
Warn(format string, v ...any)
Error(format string, v ...any)
Critical(format string, v ...any)
}
type Logger interface {
BaseLogger
LevelLogger
}
type LogStringer interface { //nolint:revive
LogString() string
}