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>

Author: 4 people

cmd/cmd.go

@@ -9,6 +9,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io"
 	"os"
 	"os/signal"
 	"strings"
@@ -59,7 +60,7 @@ func confirm() (bool, error) {
 func initDB(ctx context.Context) error {
 	setting.Init(&setting.Options{})
 	setting.LoadDBSetting()
-	setting.InitSQLLog(false)
+	setting.InitSQLLoggersForCli(log.INFO)
 
 	if setting.Database.Type == "" {
 		log.Fatal(`Database settings are missing from the configuration file: %q.
@@ -93,3 +94,17 @@ func installSignals() (context.Context, context.CancelFunc) {
 
 	return ctx, cancel
 }
+
+func setupConsoleLogger(level log.Level, colorize bool, out io.Writer) {
+	if out != os.Stdout && out != os.Stderr {
+		panic("setupConsoleLogger can only be used with os.Stdout or os.Stderr")
+	}
+
+	writeMode := log.WriterMode{
+		Level:        level,
+		Colorize:     colorize,
+		WriterOption: log.WriterConsoleOption{Stderr: out == os.Stderr},
+	}
+	writer := log.NewEventWriterConsole("console-default", writeMode)
+	log.GetManager().GetLogger(log.DEFAULT).RemoveAllWriters().AddWriters(writer)
+}

cmd/doctor.go

@@ -4,10 +4,10 @@
 package cmd
 
 import (
-	"errors"
 	"fmt"
 	golog "log"
 	"os"
+	"path/filepath"
 	"strings"
 	"text/tabwriter"
 
@@ -82,23 +82,25 @@ You should back-up your database before doing this and ensure that your database
 }
 
 func runRecreateTable(ctx *cli.Context) error {
+	stdCtx, cancel := installSignals()
+	defer cancel()
+
 	// Redirect the default golog to here
 	golog.SetFlags(0)
 	golog.SetPrefix("")
-	golog.SetOutput(log.NewLoggerAsWriter("INFO", log.GetLogger(log.DEFAULT)))
+	golog.SetOutput(log.LoggerToWriter(log.GetLogger(log.DEFAULT).Info))
 
+	debug := ctx.Bool("debug")
 	setting.Init(&setting.Options{})
 	setting.LoadDBSetting()
 
-	setting.Log.EnableXORMLog = ctx.Bool("debug")
-	setting.Database.LogSQL = ctx.Bool("debug")
-	// FIXME: don't use CfgProvider directly
-	setting.CfgProvider.Section("log").Key("XORM").SetValue(",")
-
-	setting.InitSQLLog(!ctx.Bool("debug"))
-	stdCtx, cancel := installSignals()
-	defer cancel()
+	if debug {
+		setting.InitSQLLoggersForCli(log.DEBUG)
+	} else {
+		setting.InitSQLLoggersForCli(log.INFO)
+	}
 
+	setting.Database.LogSQL = debug
 	if err := db.InitEngine(stdCtx); err != nil {
 		fmt.Println(err)
 		fmt.Println("Check if you are using the right config file. You can use a --config directive to specify one.")
@@ -125,67 +127,49 @@ func runRecreateTable(ctx *cli.Context) error {
 	})
 }
 
-func setDoctorLogger(ctx *cli.Context) {
+func setupDoctorDefaultLogger(ctx *cli.Context, colorize bool) {
+	// Silence the default loggers
+	setupConsoleLogger(log.FATAL, log.CanColorStderr, os.Stderr)
+
 	logFile := ctx.String("log-file")
 	if !ctx.IsSet("log-file") {
 		logFile = "doctor.log"
 	}
-	colorize := log.CanColorStdout
-	if ctx.IsSet("color") {
-		colorize = ctx.Bool("color")
-	}
 
 	if len(logFile) == 0 {
-		log.NewLogger(1000, "doctor", "console", fmt.Sprintf(`{"level":"NONE","stacktracelevel":"NONE","colorize":%t}`, colorize))
+		// if no doctor log-file is set, do not show any log from default logger
 		return
 	}
 
-	defer func() {
-		recovered := recover()
-		if recovered == nil {
-			return
-		}
-
-		err, ok := recovered.(error)
-		if !ok {
-			panic(recovered)
-		}
-		if errors.Is(err, os.ErrPermission) {
-			fmt.Fprintf(os.Stderr, "ERROR: Unable to write logs to provided file due to permissions error: %s\n       %v\n", logFile, err)
-		} else {
-			fmt.Fprintf(os.Stderr, "ERROR: Unable to write logs to provided file: %s\n       %v\n", logFile, err)
-		}
-		fmt.Fprintf(os.Stderr, "WARN: Logging will be disabled\n       Use `--log-file` to configure log file location\n")
-		log.NewLogger(1000, "doctor", "console", fmt.Sprintf(`{"level":"NONE","stacktracelevel":"NONE","colorize":%t}`, colorize))
-	}()
-
 	if logFile == "-" {
-		log.NewLogger(1000, "doctor", "console", fmt.Sprintf(`{"level":"trace","stacktracelevel":"NONE","colorize":%t}`, colorize))
+		setupConsoleLogger(log.TRACE, colorize, os.Stdout)
 	} else {
-		log.NewLogger(1000, "doctor", "file", fmt.Sprintf(`{"filename":%q,"level":"trace","stacktracelevel":"NONE"}`, logFile))
+		logFile, _ = filepath.Abs(logFile)
+		writeMode := log.WriterMode{Level: log.TRACE, WriterOption: log.WriterFileOption{FileName: logFile}}
+		writer, err := log.NewEventWriter("console-to-file", "file", writeMode)
+		if err != nil {
+			log.FallbackErrorf("unable to create file log writer: %v", err)
+			return
+		}
+		log.GetManager().GetLogger(log.DEFAULT).RemoveAllWriters().AddWriters(writer)
 	}
 }
 
 func runDoctor(ctx *cli.Context) error {
 	stdCtx, cancel := installSignals()
 	defer cancel()
 
-	// Silence the default loggers
-	log.DelNamedLogger("console")
-	log.DelNamedLogger(log.DEFAULT)
-
-	// Now setup our own
-	setDoctorLogger(ctx)
-
 	colorize := log.CanColorStdout
 	if ctx.IsSet("color") {
 		colorize = ctx.Bool("color")
 	}
 
-	// Finally redirect the default golog to here
+	setupDoctorDefaultLogger(ctx, colorize)
+
+	// Finally redirect the default golang's log to here
 	golog.SetFlags(0)
 	golog.SetPrefix("")
-	golog.SetOutput(log.NewLoggerAsWriter("INFO", log.GetLogger(log.DEFAULT)))
+	golog.SetOutput(log.LoggerToWriter(log.GetLogger(log.DEFAULT).Info))
 
 	if ctx.IsSet("list") {
 		w := tabwriter.NewWriter(os.Stdout, 0, 8, 1, '\t', 0)
@@ -233,17 +217,5 @@ func runDoctor(ctx *cli.Context) error {
 		}
 	}
 
-	// Now we can set up our own logger to return information about what the doctor is doing
-	if err := log.NewNamedLogger("doctorouter",
-		0,
-		"console",
-		"console",
-		fmt.Sprintf(`{"level":"INFO","stacktracelevel":"NONE","colorize":%t,"flags":-1}`, colorize)); err != nil {
-		fmt.Println(err)
-		return err
-	}
-
-	logger := log.GetLogger("doctorouter")
-	defer logger.Close()
-	return doctor.RunChecks(stdCtx, logger, ctx.Bool("fix"), checks)
+	return doctor.RunChecks(stdCtx, colorize, ctx.Bool("fix"), checks)
 }

cmd/dump.go

@@ -172,10 +172,7 @@ func runDump(ctx *cli.Context) error {
 	outType := ctx.String("type")
 	if fileName == "-" {
 		file = os.Stdout
-		err := log.DelLogger("console")
-		if err != nil {
-			fatal("Deleting default logger failed. Can not write to stdout: %v", err)
-		}
+		setupConsoleLogger(log.FATAL, log.CanColorStderr, os.Stderr)
 	} else {
 		for _, suffix := range outputTypeEnum.Enum {
 			if strings.HasSuffix(fileName, "."+suffix) {

cmd/embedded.go

@@ -97,13 +97,7 @@ type assetFile struct {
 }
 
 func initEmbeddedExtractor(c *cli.Context) error {
-	// FIXME: there is a bug, if the user runs `gitea embedded` with a different user or root,
-	// The setting.Init (loadRunModeFrom) will fail and do log.Fatal
-	// But the console logger has been deleted, so nothing is printed, the user sees nothing and Gitea just exits.
-
-	// Silence the console logger
-	log.DelNamedLogger("console")
-	log.DelNamedLogger(log.DEFAULT)
+	setupConsoleLogger(log.ERROR, log.CanColorStderr, os.Stderr)
 
 	// Read configuration file
 	setting.Init(&setting.Options{

cmd/manager_logging.go

@@ -16,13 +16,13 @@ import (
 var (
 	defaultLoggingFlags = []cli.Flag{
 		cli.StringFlag{
-			Name:  "group, g",
-			Usage: "Group to add logger to - will default to \"default\"",
+			Name:  "logger",
+			Usage: `Logger name - will default to "default"`,
 		}, cli.StringFlag{
-			Name:  "name, n",
-			Usage: "Name of the new logger - will default to mode",
+			Name:  "writer",
+			Usage: "Name of the log writer - will default to mode",
 		}, cli.StringFlag{
-			Name:  "level, l",
+			Name:  "level",
 			Usage: "Logging level for the new logger",
 		}, cli.StringFlag{
 			Name:  "stacktrace-level, L",
@@ -83,8 +83,8 @@ var (
 					cli.BoolFlag{
 						Name: "debug",
 					}, cli.StringFlag{
-						Name:  "group, g",
-						Usage: "Group to add logger to - will default to \"default\"",
+						Name:  "logger",
+						Usage: `Logger name - will default to "default"`,
 					},
 				},
 				Action: runRemoveLogger,
@@ -93,15 +93,6 @@ var (
 				Usage: "Add a logger",
 				Subcommands: []cli.Command{
 					{
-						Name:  "console",
-						Usage: "Add a console logger",
-						Flags: append(defaultLoggingFlags,
-							cli.BoolFlag{
-								Name:  "stderr",
-								Usage: "Output console logs to stderr - only relevant for console",
-							}),
-						Action: runAddConsoleLogger,
-					}, {
 						Name:  "file",
 						Usage: "Add a file logger",
 						Flags: append(defaultLoggingFlags, []cli.Flag{
@@ -148,28 +139,6 @@ var (
 							},
 						}...),
 						Action: runAddConnLogger,
-					}, {
-						Name:  "smtp",
-						Usage: "Add an SMTP logger",
-						Flags: append(defaultLoggingFlags, []cli.Flag{
-							cli.StringFlag{
-								Name:  "username, u",
-								Usage: "Mail server username",
-							}, cli.StringFlag{
-								Name:  "password, P",
-								Usage: "Mail server password",
-							}, cli.StringFlag{
-								Name:  "host, H",
-								Usage: "Mail server host (defaults to: 127.0.0.1:25)",
-							}, cli.StringSliceFlag{
-								Name:  "send-to, s",
-								Usage: "Email address(es) to send to",
-							}, cli.StringFlag{
-								Name:  "subject, S",
-								Usage: "Subject header of sent emails",
-							},
-						}...),
-						Action: runAddSMTPLogger,
 					},
 				},
 			}, {
@@ -194,50 +163,16 @@ func runRemoveLogger(c *cli.Context) error {
 	defer cancel()
 
 	setup(ctx, c.Bool("debug"))
-	group := c.String("group")
-	if len(group) == 0 {
-		group = log.DEFAULT
+	logger := c.String("logger")
+	if len(logger) == 0 {
+		logger = log.DEFAULT
 	}
-	name := c.Args().First()
+	writer := c.Args().First()
 
-	extra := private.RemoveLogger(ctx, group, name)
+	extra := private.RemoveLogger(ctx, logger, writer)
 	return handleCliResponseExtra(extra)
 }
 
-func runAddSMTPLogger(c *cli.Context) error {
-	ctx, cancel := installSignals()
-	defer cancel()
-
-	setup(ctx, c.Bool("debug"))
-	vals := map[string]interface{}{}
-	mode := "smtp"
-	if c.IsSet("host") {
-		vals["host"] = c.String("host")
-	} else {
-		vals["host"] = "127.0.0.1:25"
-	}
-
-	if c.IsSet("username") {
-		vals["username"] = c.String("username")
-	}
-	if c.IsSet("password") {
-		vals["password"] = c.String("password")
-	}
-
-	if !c.IsSet("send-to") {
-		return fmt.Errorf("Some recipients must be provided")
-	}
-	vals["sendTos"] = c.StringSlice("send-to")
-
-	if c.IsSet("subject") {
-		vals["subject"] = c.String("subject")
-	} else {
-		vals["subject"] = "Diagnostic message from Gitea"
-	}
-
-	return commonAddLogger(c, mode, vals)
-}
-
 func runAddConnLogger(c *cli.Context) error {
 	ctx, cancel := installSignals()
 	defer cancel()
@@ -301,25 +236,12 @@ func runAddFileLogger(c *cli.Context) error {
 	return commonAddLogger(c, mode, vals)
 }
 
-func runAddConsoleLogger(c *cli.Context) error {
-	ctx, cancel := installSignals()
-	defer cancel()
-
-	setup(ctx, c.Bool("debug"))
-	vals := map[string]interface{}{}
-	mode := "console"
-	if c.IsSet("stderr") && c.Bool("stderr") {
-		vals["stderr"] = c.Bool("stderr")
-	}
-	return commonAddLogger(c, mode, vals)
-}
-
 func commonAddLogger(c *cli.Context, mode string, vals map[string]interface{}) error {
 	if len(c.String("level")) > 0 {
-		vals["level"] = log.FromString(c.String("level")).String()
+		vals["level"] = log.LevelFromString(c.String("level")).String()
 	}
 	if len(c.String("stacktrace-level")) > 0 {
-		vals["stacktraceLevel"] = log.FromString(c.String("stacktrace-level")).String()
+		vals["stacktraceLevel"] = log.LevelFromString(c.String("stacktrace-level")).String()
 	}
 	if len(c.String("expression")) > 0 {
 		vals["expression"] = c.String("expression")
@@ -333,18 +255,18 @@ func commonAddLogger(c *cli.Context, mode string, vals map[string]interface{}) e
 	if c.IsSet("color") {
 		vals["colorize"] = c.Bool("color")
 	}
-	group := "default"
-	if c.IsSet("group") {
-		group = c.String("group")
+	logger := log.DEFAULT
+	if c.IsSet("logger") {
+		logger = c.String("logger")
 	}
-	name := mode
-	if c.IsSet("name") {
-		name = c.String("name")
+	writer := mode
+	if c.IsSet("writer") {
+		writer = c.String("writer")
 	}
 	ctx, cancel := installSignals()
 	defer cancel()
 
-	extra := private.AddLogger(ctx, group, name, mode, vals)
+	extra := private.AddLogger(ctx, logger, writer, mode, vals)
 	return handleCliResponseExtra(extra)
 }