buildx/vendor/github.com/moby/buildkit/util/progress/progressui/init.go

package progressui

import (
	"os"
	"runtime"
	"strconv"

	"github.com/morikuni/aec"
)

var colorRun aec.ANSI
var colorCancel aec.ANSI
var colorWarning aec.ANSI
var colorError aec.ANSI

const termHeightMin = 6

var termHeightInitial = termHeightMin
var termHeight = termHeightMin

func init() {
	// As recommended on https://no-color.org/
	if v := os.Getenv("NO_COLOR"); v != "" {
		// nil values will result in no ANSI color codes being emitted.
		return
	} else if runtime.GOOS == "windows" {
		colorRun = termColorMap["cyan"]
		colorCancel = termColorMap["yellow"]
		colorWarning = termColorMap["yellow"]
		colorError = termColorMap["red"]
	} else {
		colorRun = termColorMap["blue"]
		colorCancel = termColorMap["yellow"]
		colorWarning = termColorMap["yellow"]
		colorError = termColorMap["red"]
	}

	// Loosely based on the standard set by Linux LS_COLORS.
	if _, ok := os.LookupEnv("BUILDKIT_COLORS"); ok {
		envColorString := os.Getenv("BUILDKIT_COLORS")
		setUserDefinedTermColors(envColorString)
	}

	// Make the terminal height configurable at runtime.
	termHeightStr := os.Getenv("BUILDKIT_TTY_LOG_LINES")
	if termHeightStr != "" {
		termHeightVal, err := strconv.Atoi(termHeightStr)
		if err == nil && termHeightVal > 0 {
			termHeightInitial = termHeightVal
			termHeight = termHeightVal
		}
	}
}