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# Copyright (C) 2006, 2007, 2010, 2011, 2012, 2013 Google Inc.

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# This program is distributed in the hope that it will be useful, but

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# General Public License for more details.

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# You should have received a copy of the GNU General Public License

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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

# 02110-1301, USA.

"""DRBD information parsing utilities"""

import errno

import pyparsing as pyp

import re

from ganeti import constants

from ganeti import utils

from ganeti import errors

from ganeti import compat

from ganeti.block import base

class DRBD8Status(object): # pylint: disable=R0902

  """A DRBD status representation class.

  Note that this class is meant to be used to parse one of the entries returned

  from L{DRBD8Info._JoinLinesPerMinor}.

  """

  UNCONF_RE = re.compile(r"\s*[0-9]+:\s*cs:Unconfigured$")

  LINE_RE = re.compile(r"\s*[0-9]+:\s*cs:(\S+)\s+(?:st|ro):([^/]+)/(\S+)"

                       "\s+ds:([^/]+)/(\S+)\s+.*$")

  SYNC_RE = re.compile(r"^.*\ssync'ed:\s*([0-9.]+)%.*"

                       # Due to a bug in drbd in the kernel, introduced in

                       # commit 4b0715f096 (still unfixed as of 2011-08-22)

                       "(?:\s|M)"

                       "finish: ([0-9]+):([0-9]+):([0-9]+)\s.*$")

  CS_UNCONFIGURED = "Unconfigured"

  CS_STANDALONE = "StandAlone"

  CS_WFCONNECTION = "WFConnection"

  CS_WFREPORTPARAMS = "WFReportParams"

  CS_CONNECTED = "Connected"

  CS_STARTINGSYNCS = "StartingSyncS"

  CS_STARTINGSYNCT = "StartingSyncT"

  CS_WFBITMAPS = "WFBitMapS"

  CS_WFBITMAPT = "WFBitMapT"

  CS_WFSYNCUUID = "WFSyncUUID"

  CS_SYNCSOURCE = "SyncSource"

  CS_SYNCTARGET = "SyncTarget"

  CS_PAUSEDSYNCS = "PausedSyncS"

  CS_PAUSEDSYNCT = "PausedSyncT"

  CSET_SYNC = compat.UniqueFrozenset([

    CS_WFREPORTPARAMS,

    CS_STARTINGSYNCS,

    CS_STARTINGSYNCT,

    CS_WFBITMAPS,

    CS_WFBITMAPT,

    CS_WFSYNCUUID,

    CS_SYNCSOURCE,

    CS_SYNCTARGET,

    CS_PAUSEDSYNCS,

    CS_PAUSEDSYNCT,

    ])

  DS_DISKLESS = "Diskless"

  DS_ATTACHING = "Attaching" # transient state

  DS_FAILED = "Failed" # transient state, next: diskless

  DS_NEGOTIATING = "Negotiating" # transient state

  DS_INCONSISTENT = "Inconsistent" # while syncing or after creation

  DS_OUTDATED = "Outdated"

  DS_DUNKNOWN = "DUnknown" # shown for peer disk when not connected

  DS_CONSISTENT = "Consistent"

  DS_UPTODATE = "UpToDate" # normal state

  RO_PRIMARY = "Primary"

  RO_SECONDARY = "Secondary"

  RO_UNKNOWN = "Unknown"

  def __init__(self, procline):

    u = self.UNCONF_RE.match(procline)

    if u:

      self.cstatus = self.CS_UNCONFIGURED

      self.lrole = self.rrole = self.ldisk = self.rdisk = None

    else:

      m = self.LINE_RE.match(procline)

      if not m:

        raise errors.BlockDeviceError("Can't parse input data '%s'" % procline)

      self.cstatus = m.group(1)

      self.lrole = m.group(2)

      self.rrole = m.group(3)

      self.ldisk = m.group(4)

      self.rdisk = m.group(5)

    # end reading of data from the LINE_RE or UNCONF_RE

    self.is_standalone = self.cstatus == self.CS_STANDALONE

    self.is_wfconn = self.cstatus == self.CS_WFCONNECTION

    self.is_connected = self.cstatus == self.CS_CONNECTED

    self.is_unconfigured = self.cstatus == self.CS_UNCONFIGURED

    self.is_primary = self.lrole == self.RO_PRIMARY

    self.is_secondary = self.lrole == self.RO_SECONDARY

    self.peer_primary = self.rrole == self.RO_PRIMARY

    self.peer_secondary = self.rrole == self.RO_SECONDARY

    self.both_primary = self.is_primary and self.peer_primary

    self.both_secondary = self.is_secondary and self.peer_secondary

    self.is_diskless = self.ldisk == self.DS_DISKLESS

    self.is_disk_uptodate = self.ldisk == self.DS_UPTODATE

    self.is_in_resync = self.cstatus in self.CSET_SYNC

    self.is_in_use = self.cstatus != self.CS_UNCONFIGURED

    m = self.SYNC_RE.match(procline)

    if m:

      self.sync_percent = float(m.group(1))

      hours = int(m.group(2))

      minutes = int(m.group(3))

      seconds = int(m.group(4))

      self.est_time = hours * 3600 + minutes * 60 + seconds

    else:

      # we have (in this if branch) no percent information, but if

      # we're resyncing we need to 'fake' a sync percent information,

      # as this is how cmdlib determines if it makes sense to wait for

      # resyncing or not

      if self.is_in_resync:

        self.sync_percent = 0

      else:

        self.sync_percent = None

      self.est_time = None

class DRBD8Info(object):

  """Represents information DRBD exports (usually via /proc/drbd).

  An instance of this class is created by one of the CreateFrom... methods.

  """

  _VERSION_RE = re.compile(r"^version: (\d+)\.(\d+)\.(\d+)(?:\.(\d+))?"

                           r" \(api:(\d+)/proto:(\d+)(?:-(\d+))?\)")

  _VALID_LINE_RE = re.compile("^ *([0-9]+): cs:([^ ]+).*$")

  def __init__(self, lines):

    self._version = self._ParseVersion(lines)

    self._minors, self._line_per_minor = self._JoinLinesPerMinor(lines)

  def GetVersion(self):

    """Return the DRBD version.

    This will return a dict with keys:

      - k_major

      - k_minor

      - k_point

      - k_fix (only on some drbd versions)

      - api

      - proto

      - proto2 (only on drbd > 8.2.X)

    """

    return self._version

  def GetVersionString(self):

    """Return the DRBD version as a single string.

    """

    version = self.GetVersion()

    retval = "%d.%d.%d" % \

             (version["k_major"], version["k_minor"], version["k_point"])

    if "k_fix" in version:

      retval += ".%s" % version["k_fix"]

    retval += " (api:%d/proto:%d" % (version["api"], version["proto"])

    if "proto2" in version:

      retval += "-%s" % version["proto2"]

    retval += ")"

    return retval

  def GetMinors(self):

    """Return a list of minor for which information is available.

    This list is ordered in exactly the order which was found in the underlying

    data.

    """

    return self._minors

  def HasMinorStatus(self, minor):

    return minor in self._line_per_minor

  def GetMinorStatus(self, minor):

    return DRBD8Status(self._line_per_minor[minor])

  def _ParseVersion(self, lines):

    first_line = lines[0].strip()

    version = self._VERSION_RE.match(first_line)

    if not version:

      raise errors.BlockDeviceError("Can't parse DRBD version from '%s'" %

                                    first_line)

    values = version.groups()

    retval = {

      "k_major": int(values[0]),

      "k_minor": int(values[1]),

      "k_point": int(values[2]),

      "api": int(values[4]),

      "proto": int(values[5]),

      }

    if values[3] is not None:

      retval["k_fix"] = values[3]

    if values[6] is not None:

      retval["proto2"] = values[6]

    return retval

  def _JoinLinesPerMinor(self, lines):

    """Transform the raw lines into a dictionary based on the minor.

    @return: a dictionary of minor: joined lines from /proc/drbd

        for that minor

    """

    minors = []

    results = {}

    old_minor = old_line = None

    for line in lines:

      if not line: # completely empty lines, as can be returned by drbd8.0+

        continue

      lresult = self._VALID_LINE_RE.match(line)

      if lresult is not None:

        if old_minor is not None:

          minors.append(old_minor)

          results[old_minor] = old_line

        old_minor = int(lresult.group(1))

        old_line = line

      else:

        if old_minor is not None:

          old_line += " " + line.strip()

    # add last line

    if old_minor is not None:

      minors.append(old_minor)

      results[old_minor] = old_line

    return minors, results

  @staticmethod

  def CreateFromLines(lines):

    return DRBD8Info(lines)

  @staticmethod

  def CreateFromFile(filename=constants.DRBD_STATUS_FILE):

    try:

      lines = utils.ReadFile(filename).splitlines()

    except EnvironmentError, err:

      if err.errno == errno.ENOENT:

        base.ThrowError("The file %s cannot be opened, check if the module"

                        " is loaded (%s)", filename, str(err))

      else:

        base.ThrowError("Can't read the DRBD proc file %s: %s",

                        filename, str(err))

    if not lines:

      base.ThrowError("Can't read any data from %s", filename)

    return DRBD8Info.CreateFromLines(lines)

class BaseShowInfo(object):

  """Base class for parsing the `drbdsetup show` output.

  Holds various common pyparsing expressions which are used by subclasses. Also

  provides caching of the constructed parser.

  """

  _PARSE_SHOW = None

  # pyparsing setup

  _lbrace = pyp.Literal("{").suppress()

  _rbrace = pyp.Literal("}").suppress()

  _lbracket = pyp.Literal("[").suppress()

  _rbracket = pyp.Literal("]").suppress()

  _semi = pyp.Literal(";").suppress()

  _colon = pyp.Literal(":").suppress()

  # this also converts the value to an int

  _number = pyp.Word(pyp.nums).setParseAction(lambda s, l, t: int(t[0]))

  _comment = pyp.Literal("#") + pyp.Optional(pyp.restOfLine)

  _defa = pyp.Literal("_is_default").suppress()

  _dbl_quote = pyp.Literal('"').suppress()

  _keyword = pyp.Word(pyp.alphanums + "-")

  # value types

  _value = pyp.Word(pyp.alphanums + "_-/.:")

  _quoted = _dbl_quote + pyp.CharsNotIn('"') + _dbl_quote

  _ipv4_addr = (pyp.Optional(pyp.Literal("ipv4")).suppress() +

                pyp.Word(pyp.nums + ".") + _colon + _number)

  _ipv6_addr = (pyp.Optional(pyp.Literal("ipv6")).suppress() +

                pyp.Optional(_lbracket) + pyp.Word(pyp.hexnums + ":") +

                pyp.Optional(_rbracket) + _colon + _number)

  # meta device, extended syntax

  _meta_value = ((_value ^ _quoted) + _lbracket + _number + _rbracket)

  # device name, extended syntax

  _device_value = pyp.Literal("minor").suppress() + _number

  # a statement

  _stmt = (~_rbrace + _keyword + ~_lbrace +

           pyp.Optional(_ipv4_addr ^ _ipv6_addr ^ _value ^ _quoted ^

                        _meta_value ^ _device_value) +

           pyp.Optional(_defa) + _semi +

           pyp.Optional(pyp.restOfLine).suppress())

  @classmethod

  def GetDevInfo(cls, show_data):

    """Parse details about a given DRBD minor.

    This returns, if available, the local backing device (as a path)

    and the local and remote (ip, port) information from a string

    containing the output of the `drbdsetup show` command as returned

    by DRBD8Dev._GetShowData.

    This will return a dict with keys:

      - local_dev

      - meta_dev

      - meta_index

      - local_addr

      - remote_addr

    """

    if not show_data:

      return {}

    try:

      # run pyparse

      results = (cls._GetShowParser()).parseString(show_data)

    except pyp.ParseException, err:

      base.ThrowError("Can't parse drbdsetup show output: %s", str(err))

    return cls._TransformParseResult(results)

  @classmethod

  def _TransformParseResult(cls, parse_result):

    raise NotImplementedError

  @classmethod

  def _GetShowParser(cls):

    """Return a parser for `drbd show` output.

    This will either create or return an already-created parser for the

    output of the command `drbd show`.

    """

    if cls._PARSE_SHOW is None:

      cls._PARSE_SHOW = cls._ConstructShowParser()

    return cls._PARSE_SHOW

  @classmethod

  def _ConstructShowParser(cls):

    raise NotImplementedError

class DRBD83ShowInfo(BaseShowInfo):

  @classmethod

  def _ConstructShowParser(cls):

    # an entire section

    section_name = pyp.Word(pyp.alphas + "_")

    section = section_name + \

              cls._lbrace + \

              pyp.ZeroOrMore(pyp.Group(cls._stmt)) + \

              cls._rbrace

    bnf = pyp.ZeroOrMore(pyp.Group(section ^ cls._stmt))

    bnf.ignore(cls._comment)

    return bnf

  @classmethod

  def _TransformParseResult(cls, parse_result):

    retval = {}

    for section in parse_result:

      sname = section[0]

      if sname == "_this_host":

        for lst in section[1:]:

          if lst[0] == "disk":

            retval["local_dev"] = lst[1]

          elif lst[0] == "meta-disk":

            retval["meta_dev"] = lst[1]

            retval["meta_index"] = lst[2]

          elif lst[0] == "address":

            retval["local_addr"] = tuple(lst[1:])

      elif sname == "_remote_host":

        for lst in section[1:]:

          if lst[0] == "address":

            retval["remote_addr"] = tuple(lst[1:])

    return retval

class DRBD84ShowInfo(BaseShowInfo):

  @classmethod

  def _ConstructShowParser(cls):

    # an entire section (sections can be nested in DRBD 8.4, and there exist

    # sections like "volume 0")

    section_name = pyp.Word(pyp.alphas + "_") + \

                   pyp.Optional(pyp.Word(pyp.nums)).suppress() # skip volume idx

    section = pyp.Forward()

    # pylint: disable=W0106

    section << (section_name +

                cls._lbrace +

                pyp.ZeroOrMore(pyp.Group(cls._stmt ^ section)) +

                cls._rbrace)

    resource_name = pyp.Word(pyp.alphanums + "_-.")

    resource = (pyp.Literal("resource") + resource_name).suppress() + \

               cls._lbrace + \

               pyp.ZeroOrMore(pyp.Group(section)) + \

               cls._rbrace

    resource.ignore(cls._comment)

    return resource

  @classmethod

  def _TransformParseResult(cls, parse_result):

    retval = {}

    for section in parse_result:

      sname = section[0]

      if sname == "_this_host":

        for lst in section[1:]:

          if lst[0] == "address":

            retval["local_addr"] = tuple(lst[1:])

          elif lst[0] == "volume":

            for inner in lst[1:]:

              if inner[0] == "disk" and len(inner) == 2:

                retval["local_dev"] = inner[1]

              elif inner[0] == "meta-disk" and len(inner) == 3:

                retval["meta_dev"] = inner[1]

                retval["meta_index"] = inner[2]

      elif sname == "_remote_host":

        for lst in section[1:]:

          if lst[0] == "address":

            retval["remote_addr"] = tuple(lst[1:])

    return retval