Synnefo » snf-ganeti

#!/usr/bin/python

#

# Copyright (C) 2006, 2007 Google Inc.

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

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

# WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

# General Public License for more details.

#

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

# along with this program; if not, write to the Free Software

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

# 02110-1301, USA.

"""Module dealing with command line parsing"""

import sys

import textwrap

import os.path

import copy

from ganeti import utils

from ganeti import logger

from ganeti import errors

from ganeti import mcpu

from ganeti import constants

from optparse import (OptionParser, make_option, TitledHelpFormatter,

                      Option, OptionValueError, SUPPRESS_HELP)

__all__ = ["DEBUG_OPT", "NOHDR_OPT", "SEP_OPT", "GenericMain", "SubmitOpCode",

           "cli_option",

           "ARGS_NONE", "ARGS_FIXED", "ARGS_ATLEAST", "ARGS_ANY", "ARGS_ONE",

           "USEUNITS_OPT"]

DEBUG_OPT = make_option("-d", "--debug", default=False,

                        action="store_true",

                        help="Turn debugging on")

NOHDR_OPT = make_option("--no-headers", default=False,

                        action="store_true", dest="no_headers",

                        help="Don't display column headers")

SEP_OPT = make_option("--separator", default=" ",

                      action="store", dest="separator",

                      help="Separator between output fields"

                      " (defaults to one space)")

USEUNITS_OPT = make_option("--human-readable", default=False,

                           action="store_true", dest="human_readable",

                           help="Print sizes in human readable format")

_LOCK_OPT = make_option("--lock-retries", default=None,

                        type="int", help=SUPPRESS_HELP)

def ARGS_FIXED(val):

  """Macro-like function denoting a fixed number of arguments"""

  return -val

def ARGS_ATLEAST(val):

  """Macro-like function denoting a minimum number of arguments"""

  return val

ARGS_NONE = None

ARGS_ONE = ARGS_FIXED(1)

ARGS_ANY = ARGS_ATLEAST(0)

def check_unit(option, opt, value):

  try:

    return utils.ParseUnit(value)

  except errors.UnitParseError, err:

    raise OptionValueError, ("option %s: %s" % (opt, err))

class CliOption(Option):

  TYPES = Option.TYPES + ("unit",)

  TYPE_CHECKER = copy.copy(Option.TYPE_CHECKER)

  TYPE_CHECKER["unit"] = check_unit

# optparse.py sets make_option, so we do it for our own option class, too

cli_option = CliOption

def _ParseArgs(argv, commands):

  """Parses the command line and return the function which must be

  executed together with its arguments

  Arguments:

    argv: the command line

    commands: dictionary with special contents, see the design doc for

    cmdline handling

  """

  if len(argv) == 0:

    binary = "<command>"

  else:

    binary = argv[0].split("/")[-1]

  if len(argv) > 1 and argv[1] == "--version":

    print "%s (ganeti) %s" % (binary, constants.RELEASE_VERSION)

    # Quit right away. That way we don't have to care about this special

    # argument. optparse.py does it the same.

    sys.exit(0)

  if len(argv) < 2 or argv[1] not in commands.keys():

    # let's do a nice thing

    sortedcmds = commands.keys()

    sortedcmds.sort()

    print ("Usage: %(bin)s {command} [options...] [argument...]"

           "\n%(bin)s <command> --help to see details, or"

           " man %(bin)s\n" % {"bin": binary})

    # compute the max line length for cmd + usage

    mlen = max([len(" %s %s" % (cmd, commands[cmd][3])) for cmd in commands])

    mlen = min(60, mlen) # should not get here...

    # and format a nice command list

    print "Commands:"

    for cmd in sortedcmds:

      cmdstr = " %s %s" % (cmd, commands[cmd][3])

      help_text = commands[cmd][4]

      help_lines = textwrap.wrap(help_text, 79-3-mlen)

      print "%-*s - %s" % (mlen, cmdstr,

                                          help_lines.pop(0))

      for line in help_lines:

        print "%-*s   %s" % (mlen, "", line)

    print

    return None, None, None

  cmd = argv.pop(1)

  func, nargs, parser_opts, usage, description = commands[cmd]

  parser_opts.append(_LOCK_OPT)

  parser = OptionParser(option_list=parser_opts,

                        description=description,

                        formatter=TitledHelpFormatter(),

                        usage="%%prog %s %s" % (cmd, usage))

  parser.disable_interspersed_args()

  options, args = parser.parse_args()

  if nargs is None:

    if len(args) != 0:

      print >> sys.stderr, ("Error: Command %s expects no arguments" % cmd)

      return None, None, None

  elif nargs < 0 and len(args) != -nargs:

    print >> sys.stderr, ("Error: Command %s expects %d argument(s)" %

                         (cmd, -nargs))

    return None, None, None

  elif nargs >= 0 and len(args) < nargs:

    print >> sys.stderr, ("Error: Command %s expects at least %d argument(s)" %

                         (cmd, nargs))

    return None, None, None

  return func, options, args

def _AskUser(text):

  """Ask the user a yes/no question.

  Args:

    questionstring - the question to ask.

  Returns:

    True or False depending on answer (No for False is default).

  """

  try:

    f = file("/dev/tty", "r+")

  except IOError:

    return False

  answer = False

  try:

    f.write(textwrap.fill(text))

    f.write('\n')

    f.write("y/[n]: ")

    line = f.readline(16).strip().lower()

    answer = line in ('y', 'yes')

  finally:

    f.close()

  return answer

def SubmitOpCode(op):

  """Function to submit an opcode.

  This is just a simple wrapper over the construction of the processor

  instance. It should be extended to better handle feedback and

  interaction functions.

  """

  proc = mcpu.Processor()

  return proc.ExecOpCode(op, logger.ToStdout)

def GenericMain(commands):

  """Generic main function for all the gnt-* commands.

  Argument: a dictionary with a special structure, see the design doc

  for command line handling.

  """

  # save the program name and the entire command line for later logging

  if sys.argv:

    binary = os.path.basename(sys.argv[0]) or sys.argv[0]

    if len(sys.argv) >= 2:

      binary += " " + sys.argv[1]

      old_cmdline = " ".join(sys.argv[2:])

    else:

      old_cmdline = ""

  else:

    binary = "<unknown program>"

    old_cmdline = ""

  func, options, args = _ParseArgs(sys.argv, commands)

  if func is None: # parse error

    return 1

  options._ask_user = _AskUser

  logger.SetupLogging(debug=options.debug, program=binary)

  try:

    utils.Lock('cmd', max_retries=options.lock_retries, debug=options.debug)

  except errors.LockError, err:

    logger.ToStderr(str(err))

    return 1

  if old_cmdline:

    logger.Info("run with arguments '%s'" % old_cmdline)

  else:

    logger.Info("run with no arguments")

  try:

    try:

      result = func(options, args)

    except errors.ConfigurationError, err:

      logger.Error("Corrupt configuration file: %s" % err)

      logger.ToStderr("Aborting.")

      result = 2

    except errors.HooksAbort, err:

      logger.ToStderr("Failure: hooks execution failed:")

      for node, script, out in err.args[0]:

        if out:

          logger.ToStderr("  node: %s, script: %s, output: %s" %

                          (node, script, out))

        else:

          logger.ToStderr("  node: %s, script: %s (no output)" %

                          (node, script))

      result = 1

    except errors.HooksFailure, err:

      logger.ToStderr("Failure: hooks general failure: %s" % str(err))

      result = 1

    except errors.OpPrereqError, err:

      logger.ToStderr("Failure: prerequisites not met for this"

                      " operation:\n%s" % str(err))

      result = 1

    except errors.OpExecError, err:

      logger.ToStderr("Failure: command execution error:\n%s" % str(err))

      result = 1

  finally:

    utils.Unlock('cmd')

    utils.LockCleanup()

  return result