Implement IsTerminal() to set initial CanColorStdout / CanColorStderr in console.go

[tepozoa]

Feature Description

Currently the values of CanColorStdout and CanColorStderr are set to true. The issue is when running gitea as a systemd unit with logging set to console, it spams the journal / syslog with escape sequences until the code can read the app.ini COLORIZE setting.

• https://github.com/go-gitea/gitea/blob/main/modules/log/console.go#L16

Example systemd -> console -> syslog contents that we don't want:

Apr 22 20:42:17 zuul gitea[182204]: #033[36m2022/04/22 20:42:17 #033[0m#033[32mcmd/web.go:102:#033[32mrunWeb()#033[0m #033[1;32
m[I]#033[0m Starting Gitea on PID: #033[1m182204#033[0m

Apr 22 20:42:17 zuul gitea[182204]: #033[36m2022/04/22 20:42:17 #033[0m#033[32mcmd/web.go:150:#033[32mrunWeb()#033[0m #033[1;32
m[I]#033[0m Global init

A golang module exists (and is being imported in go.mod in it's Deprecated form already) to make setting this up a better experience.

• https://pkg.go.dev/golang.org/x/crypto/ssh/terminal#IsTerminal (Deprecated, but already in gitea codebase)
• https://pkg.go.dev/golang.org/x/term#IsTerminal (new package)

The gitea code update could be as simple as:

import "golang.org/x/term"
var CanColorStdout = term.IsTerminal(int(os.Stdout.Fd()))
var CanColorStderr = term.IsTerminal(int(os.Stderr.Fd()))

Screenshots

This can be tested easily outside the codebase:

main.go

package main

import (
	"os"

	"golang.org/x/term"
)

func main() {
	if term.IsTerminal(int(os.Stdout.Fd())) {
		println("STDOUT is a term")
	} else {
		println("STDOUT not a term")
	}
	if term.IsTerminal(int(os.Stderr.Fd())) {
		println("STDERR is a term")
	} else {
		println("STDERR not a term")
	}
}

-> https://go.dev/play/ to see it run and report not a term on their server, then in your local terminals:

$ /usr/lib/go-1.16/bin/go mod init example.com/main
$ /usr/lib/go-1.16/bin/go get golang.org/x/term
$ /usr/lib/go-1.16/bin/go build main.go

$ ./main
STDOUT is a term
STDERR is a term

$ ./main 1>/dev/null
STDOUT not a term
STDERR is a term

$ ./main 2>log.txt; cat log.txt
STDOUT is a term
STDERR not a term

$ ./main 1>/dev/null 2>log.txt; cat log.txt
STDOUT not a term
STDERR not a term

$ ./main 1>log.txt 2>&1; cat log.txt
STDOUT not a term
STDERR not a term

[lunny]

For systemd, we can have a command arg to enable/disable color.

[wxiaoguang]

PR #19581

• Only set CanColorStdout / CanColorStderr to true if the stdout/stderr is a terminal #19581

No new dependency, just re-use the existing isatty package.

[tepozoa]

Thank you!