clr-installer/args/args.go

// Copyright © 2018 Intel Corporation
//
// SPDX-License-Identifier: GPL-3.0-only

package args

// Arguments which influence how this program executes
// Order of Precedence
// 1. Command Line Arguments -- Highest Priority
// 2. Kernel Command Line Arguments
// 3. Program defaults -- Lowest Priority

import (
	"errors"
	"fmt"
	"io/ioutil"
	"os"
	"os/user"
	"path/filepath"
	"strconv"
	"strings"

	"github.com/clearlinux/clr-installer/conf"
	"github.com/clearlinux/clr-installer/log"
	flag "github.com/spf13/pflag"
)

const (
	kernelCmdlineConf = "clri.descriptor"
	kernelCmdlineDemo = "clri.demo"
	kernelCmdlineLog  = "clri.loglevel"
	logFileEnvironVar = "CLR_INSTALLER_LOG_FILE"
)

var (
	kernelCmdlineFile = "/proc/cmdline"
)

// Args represents the user provided arguments
type Args struct {
	Version         bool
	Reboot          bool
	RebootSet       bool
	LogFile         string
	ConfigFile      string
	CfDownloaded    bool
	SwupdMirror     string
	SwupdStateDir   string
	Telemetry       bool
	TelemetrySet    bool
	TelemetryURL    string
	TelemetryTID    string
	TelemetryPolicy string
	PamSalt         string
	LogLevel        int
	ForceTUI        bool
	Archive         bool
	ArchiveSet      bool
	DemoMode        bool
	BlockDevices    []string
	StubImage       bool
}

func (args *Args) setKernelArgs() (err error) {
	var (
		kernelCmd string
		url       string
	)

	if kernelCmd, err = args.readKernelCmd(); err != nil {
		return err
	}

	// Parse the kernel command for relevant installer options
	for _, curr := range strings.Split(kernelCmd, " ") {
		curr = strings.TrimSpace(curr)
		if strings.HasPrefix(curr, kernelCmdlineConf+"=") {
			url = strings.Split(curr, "=")[1]
		} else if strings.HasPrefix(curr, kernelCmdlineDemo) {
			args.DemoMode = true
		} else if strings.HasPrefix(curr, kernelCmdlineLog) {
			logLevelString := strings.Split(curr, "=")[1]
			if logLevel, _ := strconv.Atoi(logLevelString); err != nil {
				log.Warning("Ignoring invalid kernel parameter %s='%s'", kernelCmdlineLog, logLevelString)
			} else {
				args.LogLevel = logLevel
			}
		}
	}

	if url != "" {
		var ffile string

		if ffile, err = conf.FetchRemoteConfigFile(url); err != nil {
			return err
		}

		args.ConfigFile = ffile
		args.CfDownloaded = true
	}

	return nil
}

// readKernelCmd returns the kernel command line
func (args *Args) readKernelCmd() (string, error) {
	content, err := ioutil.ReadFile(kernelCmdlineFile)
	if err != nil {
		return "", err
	}

	return string(content), nil
}

func (args *Args) setCommandLineArgs() (err error) {
	flag.BoolVarP(
		&args.Version, "version", "v", false, "Version of the Installer",
	)

	flag.BoolVar(
		&args.Reboot, "reboot", true, "Reboot after finishing",
	)

	flag.BoolVar(
		&args.ForceTUI, "tui", false, "Use TUI frontend",
	)

	flag.StringSliceVarP(
		&args.BlockDevices, "block-device", "b", args.BlockDevices,
		"Adds a new block-device's entry to configuration file. Format: <alias:filename>",
	)

	flag.StringVarP(
		&args.ConfigFile, "config", "c", args.ConfigFile, "Installation configuration file",
	)

	flag.StringVar(
		&args.SwupdMirror, "swupd-mirror", args.SwupdMirror, "Swupd Installation mirror URL",
	)

	flag.StringVar(
		&args.SwupdStateDir, "swupd-state", args.SwupdMirror, "Swupd state-dir",
	)

	flag.BoolVar(
		&args.Telemetry, "telemetry", args.Telemetry, "Enable Telemetry",
	)

	flag.BoolVarP(
		&args.StubImage, "stub-image", "S", args.StubImage, "Creates the filesystems only - dont perform an actual install",
	)

	flag.StringVar(
		&args.TelemetryURL, "telemetry-url", args.TelemetryURL, "Telemetry server URL",
	)

	flag.StringVar(
		&args.TelemetryTID, "telemetry-tid", args.TelemetryTID, "Telemetry server TID",
	)

	flag.StringVar(
		&args.TelemetryPolicy, "telemetry-policy", args.TelemetryPolicy, "Telemetry Policy text",
	)

	flag.StringVar(
		&args.PamSalt, "genpass", "", "Generates a PAM compatible password hash based on the provided salt string",
	)

	flag.IntVarP(
		&args.LogLevel,
		"log-level",
		"l",
		args.LogLevel,
		fmt.Sprintf("%d (debug), %d (info), %d (warning), %d (error)",
			log.LogLevelDebug, log.LogLevelInfo, log.LogLevelWarning, log.LogLevelError),
	)

	flag.BoolVar(
		&args.Archive, "archive", true, "Archive data to target after finishing",
	)

	flag.BoolVar(
		&args.DemoMode, "demo", args.DemoMode, "Demonstration mode for documentation generation",
	)
	// We do not want this flag to be shown as part of the standard help message
	fflag := flag.Lookup("demo")
	if fflag != nil {
		fflag.Hidden = true
	}

	usr, err := user.Current()
	if err != nil {
		return err
	}

	var defaultLogFile string

	// use the env var CLR_INSTALLER_LOG_FILE to determine the log file path
	if defaultLogFile = os.Getenv(logFileEnvironVar); defaultLogFile == "" {
		defaultLogFile = filepath.Join(usr.HomeDir, conf.LogFile)
	}

	flag.StringVar(
		&args.LogFile, "log-file", defaultLogFile, "The log file path",
	)

	flag.ErrHelp = errors.New("Clear Linux Installer program")

	saveConfigFile := args.ConfigFile
	flag.Parse()
	// If we have a downloaded file, but it is overridden by command line, remove the tempfile
	if args.CfDownloaded && args.ConfigFile != saveConfigFile {
		_ = os.Remove(saveConfigFile)
	}

	fflag = flag.Lookup("telemetry")
	if fflag != nil {
		if fflag.Changed {
			args.TelemetrySet = true
		}
	}

	fflag = flag.Lookup("reboot")
	if fflag != nil {
		if fflag.Changed {
			args.RebootSet = true
		}
	}

	fflag = flag.Lookup("archive")
	if fflag != nil {
		if fflag.Changed {
			args.ArchiveSet = true
		}
	}

	if (args.TelemetryURL != "" && args.TelemetryTID == "") ||
		(args.TelemetryURL == "" && args.TelemetryTID != "") {
		return errors.New("Telemetry requires both --telemetry-url and --telemetry-tid")
	}

	return nil
}

// ParseArgs will both parse the command line arguments to the program
// and read any options set on the kernel command line from boot-time
// setting the results into the Args member variables.
func (args *Args) ParseArgs() (err error) {
	// Set the default log level
	args.LogLevel = log.LogLevelInfo

	err = args.setKernelArgs()
	if err != nil {
		return err
	}

	err = args.setCommandLineArgs()
	if err != nil {
		return err
	}

	return nil
}