// addHardwareInfo adds additional information about the hardware, and how it is
// attached to the machine, to the given BlockDevice.
func addHardwareInfo(dev *storage.BlockDevice) error {
logger.Tracef(`executing "udevadm info" for %s`, dev.DeviceName)
output, err := exec.Command(
"udevadm", "info",
"-q", "property",
"--path", "/block/"+dev.DeviceName,
).Output()
if err != nil {
msg := "udevadm failed"
if output := bytes.TrimSpace(output); len(output) > 0 {
msg += fmt.Sprintf(" (%s)", output)
}
return errors.Annotate(err, msg)
}
var devpath, idBus, idSerial string
s := bufio.NewScanner(bytes.NewReader(output))
for s.Scan() {
line := s.Text()
sep := strings.IndexRune(line, '=')
if sep == -1 {
logger.Debugf("unexpected udevadm output line: %q", line)
continue
}
key, value := line[:sep], line[sep+1:]
switch key {
case "DEVPATH":
devpath = value
case "DEVLINKS":
dev.DeviceLinks = strings.Split(value, " ")
case "ID_BUS":
idBus = value
case "ID_SERIAL":
idSerial = value
default:
logger.Tracef("ignoring line: %q", line)
}
}
if err := s.Err(); err != nil {
return errors.Annotate(err, "cannot parse udevadm output")
}
if idBus != "" && idSerial != "" {
// ID_BUS will be something like "scsi" or "ata";
// ID_SERIAL will be soemthing like ${MODEL}_${SERIALNO};
// and together they make up the symlink in /dev/disk/by-id.
dev.HardwareId = idBus + "-" + idSerial
}
// For devices on the SCSI bus, we include the address. This is to
// support storage providers where the SCSI address may be specified,
// but the device name can not (and may change, depending on timing).
if idBus == "scsi" && devpath != "" {
// DEVPATH will be "<uninteresting stuff>/<SCSI address>/block/<device>".
re := regexp.MustCompile(fmt.Sprintf(
`^.*/(\d+):(\d+):(\d+):(\d+)/block/%s$`,
regexp.QuoteMeta(dev.DeviceName),
))
submatch := re.FindStringSubmatch(devpath)
if submatch != nil {
// We use the address scheme used by lshw: bus@address. We don't use
// lshw because it does things we don't need, and that slows it down.
//
// In DEVPATH, the address format is "H:C:T:L" ([H]ost, [C]hannel,
// [T]arget, [L]un); the lshw address format is "H:C.T.L"
dev.BusAddress = fmt.Sprintf(
"scsi@%s:%s.%s.%s",
submatch[1], submatch[2], submatch[3], submatch[4],
)
} else {
logger.Debugf(
"non matching DEVPATH for %q: %q",
dev.DeviceName, devpath,
)
}
}
return nil
}
