main.go

package main

import (
	"fmt"
	"os"
	"os/signal"
	"runtime/debug"
	"syscall"

	bosherr "github.com/cloudfoundry/bosh-utils/errors"
	boshlog "github.com/cloudfoundry/bosh-utils/logger"
	boshlogfile "github.com/cloudfoundry/bosh-utils/logger/file"
	boshsys "github.com/cloudfoundry/bosh-utils/system"

	boshcmd "github.com/cloudfoundry/bosh-cli/v7/cmd"
	bilog "github.com/cloudfoundry/bosh-cli/v7/logger"
	boshui "github.com/cloudfoundry/bosh-cli/v7/ui"
	boshuifmt "github.com/cloudfoundry/bosh-cli/v7/ui/fmt"
)

func main() {
	logger := newLogger()
	defer handlePanic()

	ui := boshui.NewConfUI(logger)
	defer ui.Flush()

	cmdFactory := boshcmd.NewFactory(boshcmd.NewBasicDeps(ui, logger))

	cmd, err := cmdFactory.New(os.Args[1:])
	if err != nil {
		fail(err, ui, logger)
	}

	err = cmd.Execute()
	if err != nil {
		fail(err, ui, logger)
	} else {
		success(ui, logger)
	}
}

func newLogger() boshlog.Logger {
	level := boshlog.LevelNone

	logLevelString := os.Getenv("BOSH_LOG_LEVEL")

	if logLevelString != "" {
		var err error
		level, err = boshlog.Levelify(logLevelString)
		if err != nil {
			err = bosherr.WrapError(err, "Invalid BOSH_LOG_LEVEL value")
			logger := boshlog.NewLogger(boshlog.LevelError)
			ui := boshui.NewConsoleUI(logger)
			fail(err, ui, logger)
		}
	}

	logPath := os.Getenv("BOSH_LOG_PATH")
	if logPath != "" {
		return newSignalableFileLogger(logPath, level)
	}

	return newSignalableLogger(boshlog.NewLogger(level))
}

func newSignalableLogger(logger boshlog.Logger) boshlog.Logger {
	c := make(chan os.Signal, 1)
	signal.Notify(c, syscall.SIGHUP)
	signalableLogger, _ := bilog.NewSignalableLogger(logger, c)
	return signalableLogger
}

func newSignalableFileLogger(logPath string, level boshlog.LogLevel) boshlog.Logger {
	// Log file logger errors to the STDERR logger
	logger := boshlog.NewLogger(boshlog.LevelError)
	fs := boshsys.NewOsFileSystem(logger)

	// Log file will be closed by process exit
	// Log file readable by all
	logfileLogger, _, err := boshlogfile.New(level, logPath, boshlogfile.DefaultLogFileMode, fs)
	if err != nil {
		logger := boshlog.NewLogger(boshlog.LevelError)
		ui := boshui.NewConsoleUI(logger)
		fail(err, ui, logger)
	}

	return newSignalableLogger(logfileLogger)
}

func handlePanic() {
	panic := recover()

	if panic != nil {
		var msg string
		var hideTrace bool

		switch obj := panic.(type) {
		case string:
			msg = obj
		case fmt.Stringer:
			msg = obj.String()
		case error:
			msg = obj.Error()
		case bosherr.UserError:
			msg = obj.Err.Error()
			hideTrace = true
		default:
			msg = fmt.Sprintf("%#v", obj)
		}

		// Always output to regardless of main logger's level
		logger := boshlog.NewLogger(boshlog.LevelError)
		if hideTrace {
			logger.Error("CLI", "Panic: %s", msg)
		} else {
			logger.ErrorWithDetails("CLI", "Panic: %s", msg, debug.Stack())
		}

		ui := boshui.NewConsoleUI(logger)
		fail(nil, ui, logger)
	}
}

func fail(err error, ui boshui.UI, logger boshlog.Logger) {
	if err != nil {
		logger.Error("CLI", err.Error())
		ui.ErrorLinef(boshuifmt.MultilineError(err))
	}
	ui.ErrorLinef("Exit code 1")
	ui.Flush() // todo make sure UI is flushed
	os.Exit(1)
}

func success(ui boshui.UI, logger boshlog.Logger) {
	logger.Debug("CLI", "Succeeded")
	ui.PrintLinef("Succeeded")
}