util.go

package util

import (
	"fmt"
	"io"
	"io/ioutil"
	"net"
	"os"
	"os/exec"
	"path"
	"regexp"
	"strconv"
	"time"

	log "github.com/Sirupsen/logrus"
	gofigCore "github.com/akutz/gofig"
	gofig "github.com/akutz/gofig/types"
	"github.com/akutz/gotil"

	apiversion "github.com/codedellemc/libstorage/api"
	"github.com/codedellemc/libstorage/api/context"
	apitypes "github.com/codedellemc/libstorage/api/types"

	"github.com/codedellemc/rexray/core"
)

const (
	logDirPathSuffix = "/var/log/rexray"
	etcDirPathSuffix = "/etc/rexray"
	runDirPathSuffix = "/var/run/rexray"
	libDirPathSuffix = "/var/lib/rexray"
)

var (
	prefix string

	binDirPath  string
	logDirPath  string
	libDirPath  string
	runDirPath  string
	etcDirPath  string
	pidFilePath string
	spcFilePath string
	envFilePath string

	// BinFileName is the name of the executing binary.
	BinFileName string

	// BinFilePath is the full path of the executing binary.
	BinFilePath string

	// BinFileDirPath is the full path of the executing binary's parent
	// directory.
	BinFileDirPath string

	// UnitFileName is the name of the SystemD service's unit file.
	UnitFileName string

	// UnitFilePath is the path to the SystemD service's unit file.
	UnitFilePath string

	// InitFileName is the name of the SystemV service's unit file.
	InitFileName string

	// InitFilePath is the path to the SystemV service's init script.
	InitFilePath string

	// PIDFileName is the name of the PID file.
	PIDFileName string

	// DotDirName is the name of the hidden app directory.
	DotDirName string
)

func init() {
	prefix = os.Getenv("REXRAY_HOME")
	BinFileDirPath, BinFileName, BinFilePath = gotil.GetThisPathParts()
	UnitFileName = fmt.Sprintf("%s.service", BinFileName)
	UnitFilePath = path.Join("/etc/systemd/system", UnitFileName)
	InitFileName = BinFileName
	InitFilePath = path.Join("/etc/init.d", InitFileName)
	PIDFileName = fmt.Sprintf("%s.pid", BinFileName)
	DotDirName = fmt.Sprintf(".rexray")
}

// GetPrefix gets the root path to the REX-Ray data.
func GetPrefix() string {
	return prefix
}

// Prefix sets the root path to the REX-Ray data.
func Prefix(p string) {
	if p == "" || p == "/" {
		return
	}

	logDirPath = ""
	libDirPath = ""
	runDirPath = ""
	etcDirPath = ""
	pidFilePath = ""
	spcFilePath = ""
	envFilePath = ""

	prefix = p
}

// IsPrefixed returns a flag indicating whether or not a prefix value is set.
func IsPrefixed() bool {
	return !(prefix == "" || prefix == "/")
}

// Install executes the system install command.
func Install(args ...string) {
	exec.Command("install", args...).Run()
}

// InstallChownRoot executes the system install command and chowns the target
// to the root user and group.
func InstallChownRoot(args ...string) {
	a := []string{"-o", "0", "-g", "0"}
	for _, i := range args {
		a = append(a, i)
	}
	exec.Command("install", a...).Run()
}

// InstallDirChownRoot executes the system install command with a -d flag and
// chowns the target to the root user and group.
func InstallDirChownRoot(dirPath string) {
	InstallChownRoot("-d", dirPath)
}

// EtcDirPath returns the path to the REX-Ray etc directory.
func EtcDirPath() string {
	if etcDirPath == "" {
		etcDirPath = fmt.Sprintf("%s%s", prefix, etcDirPathSuffix)
		os.MkdirAll(etcDirPath, 0755)
	}
	return etcDirPath
}

// RunDirPath returns the path to the REX-Ray run directory.
func RunDirPath() string {
	if runDirPath == "" {
		runDirPath = fmt.Sprintf("%s%s", prefix, runDirPathSuffix)
		os.MkdirAll(runDirPath, 0755)
	}
	return runDirPath
}

// LogDirPath returns the path to the REX-Ray log directory.
func LogDirPath() string {
	if logDirPath == "" {
		logDirPath = fmt.Sprintf("%s%s", prefix, logDirPathSuffix)
		os.MkdirAll(logDirPath, 0755)
	}
	return logDirPath
}

// LibDirPath returns the path to the REX-Ray bin directory.
func LibDirPath() string {
	if libDirPath == "" {
		libDirPath = fmt.Sprintf("%s%s", prefix, libDirPathSuffix)
		os.MkdirAll(libDirPath, 0755)
	}
	return libDirPath
}

// LibFilePath returns the path to a file inside the REX-Ray lib directory
// with the provided file name.
func LibFilePath(fileName string) string {
	return path.Join(LibDirPath(), fileName)
}

// RunFilePath returns the path to a file inside the REX-Ray run directory
// with the provided file name.
func RunFilePath(fileName string) string {
	return path.Join(RunDirPath(), fileName)
}

// PidFilePath returns the path to the REX-Ray PID file.
func PidFilePath() string {
	if pidFilePath == "" {
		pidFilePath = RunFilePath(fmt.Sprintf("%s.pid", BinFileName))
	}
	return pidFilePath
}

// EnvFilePath returns the path to the REX-Ray env file.
func EnvFilePath() string {
	if envFilePath == "" {
		envFilePath = EtcFilePath(fmt.Sprintf("%s.env", BinFileName))
	}
	return envFilePath
}

// SpecFilePath returns the path to the REX-Ray spec file.
func SpecFilePath() string {
	if spcFilePath == "" {
		spcFilePath = RunFilePath("rexray.spec")
	}
	return spcFilePath
}

// EtcFilePath returns the path to a file inside the REX-Ray etc directory
// with the provided file name.
func EtcFilePath(fileName string) string {
	return path.Join(EtcDirPath(), fileName)
}

// LogFilePath returns the path to a file inside the REX-Ray log directory
// with the provided file name.
func LogFilePath(fileName string) string {
	return path.Join(LogDirPath(), fileName)
}

// LogFile returns a writer to a file inside the REX-Ray log directory
// with the provided file name.
func LogFile(fileName string) (io.Writer, error) {
	return os.OpenFile(
		LogFilePath(fileName), os.O_CREATE|os.O_APPEND|os.O_RDWR, 0644)
}

// StdOutAndLogFile returns a mutltiplexed writer for the current process's
// stdout descriptor and a REX-Ray log file with the provided name.
func StdOutAndLogFile(fileName string) (io.Writer, error) {
	lf, lfErr := LogFile(fileName)
	if lfErr != nil {
		return nil, lfErr
	}
	return io.MultiWriter(os.Stdout, lf), nil
}

// WritePidFile writes the current process ID to the REX-Ray PID file.
func WritePidFile(pid int) error {
	if pid < 0 {
		pid = os.Getpid()
	}
	return gotil.WriteStringToFile(fmt.Sprintf("%d", pid), PidFilePath())
}

// ReadPidFile reads the REX-Ray PID from the PID file.
func ReadPidFile() (int, error) {
	pidStr, pidStrErr := gotil.ReadFileToString(PidFilePath())
	if pidStrErr != nil {
		return -1, pidStrErr
	}
	pid, atoiErr := strconv.Atoi(pidStr)
	if atoiErr != nil {
		return -1, atoiErr
	}
	return pid, nil
}

// WriteSpecFile writes the current host address to the REX-Ray spec file.
func WriteSpecFile(host string) error {
	return gotil.WriteStringToFile(host, SpecFilePath())
}

// ReadSpecFile reads the REX-Ray host address from the spec file.
func ReadSpecFile() (string, error) {
	host, err := gotil.ReadFileToString(SpecFilePath())
	if err != nil {
		return "", err
	}
	return gotil.Trim(host), nil
}

// PrintVersion prints the current version information to the provided writer.
func PrintVersion(out io.Writer) {
	fmt.Fprintln(out, "REX-Ray")
	fmt.Fprintln(out, "-------")
	fmt.Fprintf(out, "Binary: %s\n", BinFilePath)
	fmt.Fprintf(out, "Flavor: %s\n", core.BuildType)
	fmt.Fprintf(out, "SemVer: %s\n", core.Version.SemVer)
	fmt.Fprintf(out, "OsArch: %s\n", core.Version.Arch)
	fmt.Fprintf(out, "Branch: %s\n", core.Version.Branch)
	fmt.Fprintf(out, "Commit: %s\n", core.Version.ShaLong)
	fmt.Fprintf(out, "Formed: %s\n\n",
		core.Version.BuildTimestamp.Format(time.RFC1123))

	fmt.Fprintln(out, "libStorage")
	fmt.Fprintln(out, "----------")
	fmt.Fprintf(out, "SemVer: %s\n", apiversion.Version.SemVer)
	fmt.Fprintf(out, "OsArch: %s\n", apiversion.Version.Arch)
	fmt.Fprintf(out, "Branch: %s\n", apiversion.Version.Branch)
	fmt.Fprintf(out, "Commit: %s\n", apiversion.Version.ShaLong)

	timestamp := apiversion.Version.BuildTimestamp.Format(time.RFC1123)
	fmt.Fprintf(out, "Formed: %s\n", timestamp)
}

var localHostRX = regexp.MustCompile(
	`(?i)^(localhost|(?:127\.0\.0\.1))(?::(\d+))?$`)

func logHostSpec(ctx apitypes.Context, h, m string) {
	ctx.WithFields(log.Fields{
		"path": SpecFilePath(),
		"host": h,
	}).Debug(m)
}

// IsAddressActive returns a flag indicating whether or not a an address is
// responding to connection attempts. This does not validate whether the
// address is using TLS or such a connection is possible.
func IsAddressActive(proto, addr string) bool {
	dialer := &net.Dialer{Timeout: time.Second * 1}
	if _, err := dialer.Dial(proto, addr); err != nil {
		return false
	}
	return true
}

// IsLocalServerActive returns a flag indicating whether or not a local
// libStorage is already running.
func IsLocalServerActive(
	ctx apitypes.Context, config gofig.Config) (host string, running bool) {

	var (
		isLocal  bool
		specFile = SpecFilePath()
	)

	if gotil.FileExists(specFile) {
		if h, _ := ReadSpecFile(); h != "" {
			host = h
			logHostSpec(ctx, host, "read spec file")
			defer func() {
				if running || !isLocal {
					return
				}
				host = ""
				os.RemoveAll(specFile)
				ctx.WithField("specFile", specFile).Info(
					"removed invalid spec file")
			}()
		}
	}
	if host == "" {
		host = config.GetString(apitypes.ConfigHost)
	}
	if host == "" {
		return "", false
	}

	proto, addr, err := gotil.ParseAddress(host)
	if err != nil {
		return "", false
	}

	switch proto {
	case "unix":
		isLocal = true
		ctx.WithField("sock", addr).Debug("is local unix server active")
		var sockExists, isActive bool
		if sockExists = gotil.FileExists(addr); sockExists {
			if isActive = IsAddressActive(proto, addr); !isActive {
				os.RemoveAll(addr)
				ctx.WithField("sockFile", addr).Info(
					"removed invalid sock file")
			}
		}
		return host, isActive
	case "tcp":
		m := localHostRX.FindStringSubmatch(addr)
		if len(m) < 3 {
			return "", false
		}
		isLocal = true
		port, err := strconv.Atoi(m[2])
		if err != nil {
			return "", false
		}
		ctx.WithField("port", port).Debug("is local tcp server active")
		return host, IsAddressActive(proto, addr)
	}
	return "", false
}

// ActivateLibStorage activates libStorage and returns a possibly mutated
// context.
func ActivateLibStorage(
	ctx apitypes.Context,
	config gofig.Config) (apitypes.Context, gofig.Config, <-chan error, error) {

	config = config.Scope("rexray")

	// set the `libstorage.service` property to the value of
	// `rexray.storageDrivers` if the former is not defined and the
	// latter is
	if !config.IsSet(apitypes.ConfigService) &&
		config.IsSet("rexray.storageDrivers") {
		if sd := config.GetStringSlice("rexray.storageDrivers"); len(sd) > 0 {
			config.Set(apitypes.ConfigService, sd[0])
		} else if sd := config.GetString("rexray.storageDrivers"); sd != "" {
			config.Set(apitypes.ConfigService, sd)
		}
	}

	if !config.IsSet(apitypes.ConfigIgVolOpsMountPath) {
		config.Set(apitypes.ConfigIgVolOpsMountPath, LibFilePath("volumes"))
	}

	var (
		err  error
		errs <-chan error
	)

	ctx, config, errs, err = activateLibStorage(ctx, config)
	if err != nil {
		return ctx, config, errs, err
	}

	return ctx, config, errs, nil
}

func setHost(
	ctx apitypes.Context,
	config gofig.Config,
	host string) apitypes.Context {
	ctx = ctx.WithValue(context.HostKey, host)
	ctx.WithField("host", host).Debug("set host in context")
	config.Set(apitypes.ConfigHost, host)
	ctx.WithField("host", host).Debug("set host in config")
	return ctx
}

// WaitUntilLibStorageStopped blocks until libStorage is stopped.
func WaitUntilLibStorageStopped(ctx apitypes.Context, errs <-chan error) {
	waitUntilLibStorageStopped(ctx, errs)
}

// NewClient returns a new libStorage client.
func NewClient(
	ctx apitypes.Context, config gofig.Config) (apitypes.Client, error) {
	return newClient(ctx, config)
}

// NewConfig returns a new config object.
func NewConfig(ctx apitypes.Context) gofig.Config {
	const cfgFileExt = "yml"

	loadConfig := func(
		allExists, usrExists, ignoreExists bool,
		allPath, usrPath, name string) (gofig.Config, bool) {
		fields := log.Fields{
			"buildType":              core.BuildType,
			"ignoreExists":           ignoreExists,
			"configFileName":         name,
			"globalConfigFilePath":   allPath,
			"userConfigFilePath":     usrPath,
			"globalConfigFileExists": allExists,
			"userConfigFileExists":   usrExists,
		}
		ctx.WithFields(fields).Debug("loading config")
		if ignoreExists {
			ctx.WithFields(fields).Debug("disabled config file exist check")
		} else if !allExists && !usrExists {
			ctx.WithFields(fields).Debug("cannot find global or user file")
			return nil, false
		}
		if allExists {
			ctx.WithFields(fields).Debug("validating global config")
			ValidateConfig(allPath)
		}
		if usrExists {
			ctx.WithFields(fields).Debug("validating user config")
			ValidateConfig(usrPath)
		}
		ctx.WithFields(fields).Debug("created new config")
		return gofigCore.NewConfig(
			allExists || ignoreExists,
			usrExists || ignoreExists,
			name, cfgFileExt), true
	}

	// load build-type specific config
	switch core.BuildType {
	case "client", "agent", "controller":
		var (
			fileName    = BinFileName
			fileNameExt = fileName + "." + cfgFileExt
			allFilePath = EtcFilePath(fileNameExt)
			usrFilePath = path.Join(gotil.HomeDir(), DotDirName, fileNameExt)
		)
		if config, ok := loadConfig(
			gotil.FileExists(allFilePath),
			gotil.FileExists(usrFilePath),
			false,
			allFilePath, usrFilePath,
			fileName); ok {
			return config
		}
	}

	// load config from rexray.yml?
	{
		var (
			fileName    = "rexray"
			fileNameExt = fileName + "." + cfgFileExt
			allFilePath = EtcFilePath(fileNameExt)
			usrFilePath = path.Join(gotil.HomeDir(), DotDirName, fileNameExt)
		)
		if config, ok := loadConfig(
			gotil.FileExists(allFilePath),
			gotil.FileExists(usrFilePath),
			false,
			allFilePath, usrFilePath,
			fileName); ok {
			return config
		}
	}

	// load default config
	{
		var (
			fileName    = "config"
			fileNameExt = fileName + "." + cfgFileExt
			allFilePath = EtcFilePath(fileNameExt)
			usrFilePath = path.Join(gotil.HomeDir(), DotDirName, fileNameExt)
		)
		config, _ := loadConfig(
			gotil.FileExists(allFilePath),
			gotil.FileExists(usrFilePath),
			true,
			allFilePath, usrFilePath,
			fileName)
		return config
	}
}

// ValidateConfig validates a provided configuration file.
func ValidateConfig(path string) {
	if !gotil.FileExists(path) {
		return
	}
	buf, err := ioutil.ReadFile(path)
	if err != nil {
		fmt.Fprintf(
			os.Stderr, "rexray: error reading config: %s\n%v\n", path, err)
		os.Exit(1)
	}
	s := string(buf)
	if _, err := gofigCore.ValidateYAMLString(s); err != nil {
		fmt.Fprintf(
			os.Stderr,
			"rexray: invalid config: %s\n\n  %v\n\n", path, err)
		fmt.Fprint(
			os.Stderr,
			"paste the contents between ---BEGIN--- and ---END---\n")
		fmt.Fprint(
			os.Stderr,
			"into http://www.yamllint.com/ to discover the issue\n\n")
		fmt.Fprintln(os.Stderr, "---BEGIN---")
		fmt.Fprintln(os.Stderr, s)
		fmt.Fprintln(os.Stderr, "---END---")
		os.Exit(1)
	}
}