forgejo/docs/content/doc/administration/logging-config.en-us.md
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

12 KiB

date title slug weight toc draft aliases menu
2019-04-02T17:06:00+01:00 Logging Configuration logging-config 40 false false
/en-us/logging-configuration
sidebar
parent name weight identifier
administration Logging Configuration 40 logging-config

Logging Configuration

The logging configuration of Gitea mainly consists of 3 types of components:

  • The [log] section for general configuration
  • [log.<mode-name>] sections for the configuration of different log writers to output logs, aka: "writer mode", the mode name is also used as "writer name".
  • The [log] section can also contain sub-logger configurations following the key schema logger.<logger-name>.<CONFIG-KEY>

There is a fully functional log output by default, so it is not necessary to define one.

Table of Contents

{{< toc >}}

Collecting Logs for Help

To collect logs for help and issue report, see [Support Options]({{< relref "doc/help/support.en-us.md" >}}).

The [log] section

Configuration of logging facilities in Gitea happen in the [log] section and its subsections.

In the top level [log] section the following configurations can be placed:

  • ROOT_PATH: (Default: %(GITEA_WORK_DIR)/log): Base path for log files
  • MODE: (Default: console) List of log outputs to use for the Default logger.
  • LEVEL: (Default: Info) Least severe log events to persist, case-insensitive. Possible values are: Trace, Debug, Info, Warn, Error, Fatal.
  • STACKTRACE_LEVEL: (Default: None) For this and more severe events the stacktrace will be printed upon getting logged.

And it can contain the following sub-loggers:

  • logger.router.MODE: (Default: ,): List of log outputs to use for the Router logger.
  • logger.access.MODE: (Default: <empty>) List of log outputs to use for the Access logger. By default, the access logger is disabled.
  • logger.xorm.MODE: (Default: ,) List of log outputs to use for the XORM logger.

Setting a comma (,) to sub-logger's mode means making it use the default global MODE.

Quick samples

Default (empty) Configuration

The empty configuration is equivalent to default:

[log]
ROOT_PATH = %(GITEA_WORK_DIR)/log
MODE = console
LEVEL = Info
STACKTRACE_LEVEL = None
logger.router.MODE = ,
logger.xorm.MODE = ,
logger.access.MODE =

; this is the config options of "console" mode (used by MODE=console above)
[log.console]
MODE = console
FLAGS = stdflags
PREFIX =
COLORIZE = true

This is equivalent to sending all logs to the console, with default Golang log being sent to the console log too.

This is only a sample, and it is the default, do not need to write it into your configuration file.

Disable Router logs and record some access logs to file

The Router logger is disabled, the access logs (>=Warn) goes into access.log:

[log]
logger.router.MODE =
logger.access.MODE = access-file

[log.access-file]
MODE = file
LEVEL = Warn
FILE_NAME = access.log

Set different log levels for different modes

Default logs (>=Warn) goes into gitea.log, while Error logs goes into file-error.log:

[log]
LEVEL = Warn
MODE = file, file-error

; by default, the "file" mode will record logs to %(log.ROOT_PATH)/gitea.log, so we don't need to set it
; [log.file]

[log.file-error]
LEVEL = Error
FILE_NAME = file-error.log

Log outputs (mode and writer)

Gitea provides the following log output writers:

  • console - Log to stdout (or stderr if it is set in the config)
  • file - Log to a file
  • conn - Log to a socket (network or unix)

Common configuration

Certain configuration is common to all modes of log output:

  • MODE is the mode of the log output writer. It will default to the mode name in the ini section. Thus [log.console] will default to MODE = console.
  • LEVEL is the lowest level that this output will log.
  • STACKTRACE_LEVEL is the lowest level that this output will print a stacktrace.
  • COLORIZE will default to true for console as described, otherwise it will default to false.

EXPRESSION

EXPRESSION represents a regular expression that log events must match to be logged by the output writer. Either the log message, (with colors removed), must match or the longfilename:linenumber:functionname must match. NB: the whole message or string doesn't need to completely match.

Please note this expression will be run in the writer's goroutine but not the logging event goroutine.

FLAGS

FLAGS represents the preceding logging context information that is printed before each message. It is a comma-separated string set. The order of values does not matter.

It defaults to stdflags (= date,time,medfile,shortfuncname,levelinitial)

Possible values are:

  • none or , - No flags.
  • date - the date in the local time zone: 2009/01/23.
  • time - the time in the local time zone: 01:23:23.
  • microseconds - microsecond resolution: 01:23:23.123123. Assumes time.
  • longfile - full file name and line number: /a/b/c/d.go:23.
  • shortfile - final file name element and line number: d.go:23.
  • funcname - function name of the caller: runtime.Caller().
  • shortfuncname - last part of the function name. Overrides funcname.
  • utc - if date or time is set, use UTC rather than the local time zone.
  • levelinitial - initial character of the provided level in brackets eg. [I] for info.
  • level - level in brackets [INFO].
  • gopid - the Goroutine-PID of the context.
  • medfile - last 20 characters of the filename - equivalent to shortfile,longfile.
  • stdflags - equivalent to date,time,medfile,shortfuncname,levelinitial.

Console mode

In this mode the logger will forward log messages to the stdout and stderr streams attached to the Gitea process.

For loggers in console mode, COLORIZE will default to true if not on windows, or the Windows terminal can be set into ANSI mode or is a cygwin or Msys pipe.

Settings:

  • STDERR: false: Whether the logger should print to stderr instead of stdout.

File mode

In this mode the logger will save log messages to a file.

Settings:

  • FILE_NAME: The file to write the log events to, relative to ROOT_PATH, Default to %(ROOT_PATH)/gitea.log. Exception: access log will default to %(ROOT_PATH)/access.log.
  • MAX_SIZE_SHIFT: 28: Maximum size shift of a single file. 28 represents 256Mb. For details see below.
  • LOG_ROTATE true: Whether to rotate the log files. TODO: if false, will it delete instead on daily rotate, or do nothing?.
  • DAILY_ROTATE: true: Whether to rotate logs daily.
  • MAX_DAYS: 7: Delete rotated log files after this number of days.
  • COMPRESS: true: Whether to compress old log files by default with gzip.
  • COMPRESSION_LEVEL: -1: Compression level. For details see below.

MAX_SIZE_SHIFT defines the maximum size of a file by left shifting 1 the given number of times (1 << x). The exact behavior at the time of v1.17.3 can be seen here.

The useful values of COMPRESSION_LEVEL are from 1 to (and including) 9, where higher numbers mean better compression. Beware that better compression might come with higher resource usage. Must be preceded with a - sign.

Conn mode

In this mode the logger will send log messages over a network socket.

Settings:

  • ADDR: :7020: Sets the address to connect to.
  • PROTOCOL: tcp: Set the protocol, either "tcp", "unix" or "udp".
  • RECONNECT: false: Try to reconnect when connection is lost.
  • RECONNECT_ON_MSG: false: Reconnect host for every single message.

The "Router" logger

The Router logger logs the following message types when Gitea's route handlers work:

  • started messages will be logged at TRACE level
  • polling/completed routers will be logged at INFO. Exception: "/assets" static resource requests are also logged at TRACE.
  • slow routers will be logged at WARN
  • failed routers will be logged at WARN

The "XORM" logger

To make XORM outputs SQL logs, the LOG_SQL in [database] section should also be set to true.

The "Access" logger

The Access logger is a new logger since Gitea 1.9. It provides a NCSA Common Log compliant log format. It's highly configurable but caution should be taken when changing its template. The main benefit of this logger is that Gitea can now log accesses in a standard log format so standard tools may be used.

You can enable this logger using logger.access.MODE = ....

If desired the format of the Access logger can be changed by changing the value of the ACCESS_LOG_TEMPLATE.

Please note, the access logger will log at INFO level, setting the LEVEL of this logger to WARN or above will result in no access logs.

The ACCESS_LOG_TEMPLATE

This value represents a go template. Its default value is

{{.Ctx.RemoteHost}} - {{.Identity}} {{.Start.Format "[02/Jan/2006:15:04:05 -0700]" }} "{{.Ctx.Req.Method}} {{.Ctx.Req.URL.RequestURI}} {{.Ctx.Req.Proto}}" {{.ResponseWriter.Status}} {{.ResponseWriter.Size}} "{{.Ctx.Req.Referer}}" "{{.Ctx.Req.UserAgent}}"`

The template is passed following options:

  • Ctx is the context.Context
  • Identity is the SignedUserName or "-" if the user is not logged in
  • Start is the start time of the request
  • ResponseWriter is the http.ResponseWriter

Caution must be taken when changing this template as it runs outside of the standard panic recovery trap. The template should also be as simple as it runs for every request.

Releasing-and-Reopening, Pausing and Resuming logging

If you are running on Unix you may wish to release-and-reopen logs in order to use logrotate or other tools. It is possible force Gitea to release and reopen it's logging files and connections by sending SIGUSR1 to the running process, or running gitea manager logging release-and-reopen.

Alternatively, you may wish to pause and resume logging - this can be accomplished through the use of the gitea manager logging pause and gitea manager logging resume commands. Please note that whilst logging is paused log events below INFO level will not be stored and only a limited number of events will be stored. Logging may block, albeit temporarily, slowing Gitea considerably whilst paused - therefore it is recommended that pausing only done for a very short period of time.

Adding and removing logging whilst Gitea is running

It is possible to add and remove logging whilst Gitea is running using the gitea manager logging add and remove subcommands. This functionality can only adjust running log systems and cannot be used to start the access or router loggers if they were not already initialized. If you wish to start these systems you are advised to adjust the app.ini and (gracefully) restart the Gitea service.

The main intention of these commands is to easily add a temporary logger to investigate problems on running systems where a restart may cause the issue to disappear.

Using logrotate instead of built-in log rotation

Gitea includes built-in log rotation, which should be enough for most deployments. However, if you instead want to use the logrotate utility:

  • Disable built-in log rotation by setting LOG_ROTATE to false in your app.ini.
  • Install logrotate.
  • Configure logrotate to match your deployment requirements, see man 8 logrotate for configuration syntax details. In the postrotate/endscript block send Gitea a USR1 signal via kill -USR1 or kill -10 to the gitea process itself, or run gitea manager logging release-and-reopen (with the appropriate environment). Ensure that your configurations apply to all files emitted by Gitea loggers as described in the above sections.
  • Always do logrotate /etc/logrotate.conf --debug to test your configurations.
  • If you are using docker and are running from outside the container you can use docker exec -u $OS_USER $CONTAINER_NAME sh -c 'gitea manager logging release-and-reopen' or docker exec $CONTAINER_NAME sh -c '/bin/s6-svc -1 /etc/s6/gitea/' or send USR1 directly to the Gitea process itself.

The next logrotate jobs will include your configurations, so no restart is needed. You can also immediately reload logrotate with logrotate /etc/logrotate.conf --force.