Synnefo » snf-ganeti

#!/usr/bin/python

#

# Copyright (C) 2009 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.

import imp

import optparse

import os

import sys

import re

from cStringIO import StringIO

from ganeti import constants

from ganeti import cli

from ganeti import utils

# _autoconf shouldn't be imported from anywhere except constants.py, but we're

# making an exception here because this script is only used at build time.

from ganeti import _autoconf

class ShellWriter:

  """Helper class to write scripts with indentation.

  """

  INDENT_STR = "  "

  def __init__(self, fh):

    self._fh = fh

    self._indent = 0

  def IncIndent(self):

    """Increase indentation level by 1.

    """

    self._indent += 1

  def DecIndent(self):

    """Decrease indentation level by 1.

    """

    assert self._indent > 0

    self._indent -= 1

  def Write(self, txt, *args):

    """Write line to output file.

    """

    self._fh.write(self._indent * self.INDENT_STR)

    if args:

      self._fh.write(txt % args)

    else:

      self._fh.write(txt)

    self._fh.write("\n")

def WritePreamble(sw):

  """Writes the script preamble.

  Helper functions should be written here.

  """

  sw.Write("# This script is automatically generated at build time.")

  sw.Write("# Do not modify manually.")

  sw.Write("_ganeti_nodes() {")

  sw.IncIndent()

  try:

    node_list_path = os.path.join(constants.DATA_DIR, "ssconf_node_list")

    sw.Write("cat %s 2>/dev/null || :", utils.ShellQuote(node_list_path))

  finally:

    sw.DecIndent()

  sw.Write("}")

  sw.Write("_ganeti_instances() {")

  sw.IncIndent()

  try:

    instance_list_path = os.path.join(constants.DATA_DIR,

                                      "ssconf_instance_list")

    sw.Write("cat %s 2>/dev/null || :", utils.ShellQuote(instance_list_path))

  finally:

    sw.DecIndent()

  sw.Write("}")

  sw.Write("_ganeti_jobs() {")

  sw.IncIndent()

  try:

    # FIXME: this is really going into the internals of the job queue

    sw.Write(("local jlist=$( shopt -s nullglob &&"

              " cd %s 2>/dev/null && echo job-* || : )"),

             utils.ShellQuote(constants.QUEUE_DIR))

    sw.Write('echo "${jlist//job-/}"')

  finally:

    sw.DecIndent()

  sw.Write("}")

  sw.Write("_ganeti_os() {")

  sw.IncIndent()

  try:

    # FIXME: Make querying the master for all OSes cheap

    for path in constants.OS_SEARCH_PATH:

      sw.Write("( shopt -s nullglob && cd %s 2>/dev/null && echo * || : )",

               utils.ShellQuote(path))

  finally:

    sw.DecIndent()

  sw.Write("}")

  # Params: <offset> <options with values> <options without values>

  # Result variable: $first_arg_idx

  sw.Write("_ganeti_find_first_arg() {")

  sw.IncIndent()

  try:

    sw.Write("local w i")

    sw.Write("first_arg_idx=")

    sw.Write("for (( i=$1; i < COMP_CWORD; ++i )); do")

    sw.IncIndent()

    try:

      sw.Write("w=${COMP_WORDS[$i]}")

      # Skip option value

      sw.Write("""if [[ -n "$2" && "$w" == @($2) ]]; then let ++i""")

      # Skip

      sw.Write("""elif [[ -n "$3" && "$w" == @($3) ]]; then :""")

      # Ah, we found the first argument

      sw.Write("else first_arg_idx=$i; break;")

      sw.Write("fi")

    finally:

      sw.DecIndent()

    sw.Write("done")

  finally:

    sw.DecIndent()

  sw.Write("}")

  # Params: <list of options separated by space>

  # Input variable: $first_arg_idx

  # Result variables: $arg_idx, $choices

  sw.Write("_ganeti_list_options() {")

  sw.IncIndent()

  try:

    sw.Write("""if [[ -z "$first_arg_idx" ]]; then""")

    sw.IncIndent()

    try:

      sw.Write("arg_idx=0")

      # Show options only if the current word starts with a dash

      sw.Write("""if [[ "$cur" == -* ]]; then""")

      sw.IncIndent()

      try:

        sw.Write("choices=$1")

      finally:

        sw.DecIndent()

      sw.Write("fi")

      sw.Write("return")

    finally:

      sw.DecIndent()

    sw.Write("fi")

    # Calculate position of current argument

    sw.Write("arg_idx=$(( COMP_CWORD - first_arg_idx ))")

    sw.Write("choices=")

  finally:

    sw.DecIndent()

  sw.Write("}")

def WriteCompReply(sw, args, cur="\"$cur\""):

  sw.Write("""COMPREPLY=( $(compgen %s -- %s) )""", args, cur)

  sw.Write("return")

class CompletionWriter:

  """Command completion writer class.

  """

  def __init__(self, arg_offset, opts, args):

    self.arg_offset = arg_offset

    self.opts = opts

    self.args = args

    for opt in opts:

      opt.all_names = sorted(opt._short_opts + opt._long_opts)

  def _FindFirstArgument(self, sw):

    ignore = []

    skip_one = []

    for opt in self.opts:

      if opt.takes_value():

        # Ignore value

        for i in opt.all_names:

          if i.startswith("--"):

            ignore.append("%s=*" % utils.ShellQuote(i))

          skip_one.append(utils.ShellQuote(i))

      else:

        ignore.extend([utils.ShellQuote(i) for i in opt.all_names])

    ignore = sorted(utils.UniqueSequence(ignore))

    skip_one = sorted(utils.UniqueSequence(skip_one))

    if ignore or skip_one:

      # Try to locate first argument

      sw.Write("_ganeti_find_first_arg %s %s %s",

               self.arg_offset + 1,

               utils.ShellQuote("|".join(skip_one)),

               utils.ShellQuote("|".join(ignore)))

    else:

      # When there are no options the first argument is always at position

      # offset + 1

      sw.Write("first_arg_idx=%s", self.arg_offset + 1)

  def _CompleteOptionValues(self, sw):

    # Group by values

    # "values" -> [optname1, optname2, ...]

    values = {}

    for opt in self.opts:

      if not opt.takes_value():

        continue

      # Only static choices implemented so far (e.g. no node list)

      suggest = getattr(opt, "completion_suggest", None)

      if not suggest:

        suggest = opt.choices

      if suggest:

        suggest_text = " ".join(sorted(suggest))

      else:

        suggest_text = ""

      values.setdefault(suggest_text, []).extend(opt.all_names)

    # Don't write any code if there are no option values

    if not values:

      return

    sw.Write("if [[ $COMP_CWORD -gt %s ]]; then", self.arg_offset + 1)

    sw.IncIndent()

    try:

      # --foo value

      sw.Write("""case "$prev" in""")

      for (choices, names) in values.iteritems():

        sw.Write("%s)", "|".join([utils.ShellQuote(i) for i in names]))

        sw.IncIndent()

        try:

          WriteCompReply(sw, "-W %s" % utils.ShellQuote(choices))

        finally:

          sw.DecIndent()

        sw.Write(";;")

      sw.Write("""esac""")

    finally:

      sw.DecIndent()

    sw.Write("""fi""")

    # --foo=value

    values_longopts = {}

    for (choices, names) in values.iteritems():

      longnames = [i for i in names if i.startswith("--")]

      if longnames:

        values_longopts[choices] = longnames

    if values_longopts:

      sw.Write("""case "$cur" in""")

      for (choices, names) in values_longopts.iteritems():

        sw.Write("%s)", "|".join([utils.ShellQuote(i) + "=*" for i in names]))

        sw.IncIndent()

        try:

          # Shell expression to get option value

          cur="\"${cur#--*=}\""

          WriteCompReply(sw, "-W %s" % utils.ShellQuote(choices), cur=cur)

        finally:

          sw.DecIndent()

        sw.Write(";;")

      sw.Write("""esac""")

  def _CompleteArguments(self, sw):

    if not (self.opts or self.args):

      return

    all_option_names = []

    for opt in self.opts:

      all_option_names.extend(opt.all_names)

    all_option_names.sort()

    # List options if no argument has been specified yet

    sw.Write("_ganeti_list_options %s",

             utils.ShellQuote(" ".join(all_option_names)))

    if self.args:

      last_idx = len(self.args) - 1

      last_arg_end = 0

      varlen_arg_idx = None

      wrote_arg = False

      # Write some debug comments

      for idx, arg in enumerate(self.args):

        sw.Write("# %s: %r", idx, arg)

      sw.Write("compgenargs=")

      for idx, arg in enumerate(self.args):

        assert arg.min is not None and arg.min >= 0

        assert not (idx < last_idx and arg.max is None)

        if arg.min != arg.max or arg.max is None:

          if varlen_arg_idx is not None:

            raise Exception("Only one argument can have a variable length")

          varlen_arg_idx = idx

        compgenargs = []

        if isinstance(arg, cli.ArgUnknown):

          choices = ""

        elif isinstance(arg, cli.ArgSuggest):

          choices = utils.ShellQuote(" ".join(arg.choices))

        elif isinstance(arg, cli.ArgInstance):

          choices = "$(_ganeti_instances)"

        elif isinstance(arg, cli.ArgNode):

          choices = "$(_ganeti_nodes)"

        elif isinstance(arg, cli.ArgJobId):

          choices = "$(_ganeti_jobs)"

        elif isinstance(arg, cli.ArgFile):

          choices = ""

          compgenargs.append("-f")

        elif isinstance(arg, cli.ArgCommand):

          choices = ""

          compgenargs.append("-c")

        elif isinstance(arg, cli.ArgHost):

          choices = ""

          compgenargs.append("-A hostname")

        else:

          raise Exception("Unknown argument type %r" % arg)

        if arg.min == 1 and arg.max == 1:

          cmpcode = """"$arg_idx" == %d""" % (last_arg_end)

        elif arg.min <= arg.max:

          cmpcode = (""""$arg_idx" -ge %d && "$arg_idx" -lt %d""" %

                     (last_arg_end, last_arg_end + arg.max))

        elif arg.max is None:

          cmpcode = """"$arg_idx" -ge %d""" % (last_arg_end)

        else:

          raise Exception("Unable to generate argument position condition")

        last_arg_end += arg.min

        if choices or compgenargs:

          if wrote_arg:

            condcmd = "elif"

          else:

            condcmd = "if"

          sw.Write("""%s [[ %s ]]; then""", condcmd, cmpcode)

          sw.IncIndent()

          try:

            if choices:

              sw.Write("""choices="$choices "%s""", choices)

            if compgenargs:

              sw.Write("compgenargs=%s", utils.ShellQuote(" ".join(compgenargs)))

          finally:

            sw.DecIndent()

          wrote_arg = True

      if wrote_arg:

        sw.Write("fi")

    if self.args:

      WriteCompReply(sw, """-W "$choices" $compgenargs""")

    else:

      # $compgenargs exists only if there are arguments

      WriteCompReply(sw, '-W "$choices"')

  def WriteTo(self, sw):

    self._FindFirstArgument(sw)

    self._CompleteOptionValues(sw)

    self._CompleteArguments(sw)

def WriteCompletion(sw, scriptname, funcname,

                    commands=None,

                    opts=None, args=None):

  """Writes the completion code for one command.

  @type sw: ShellWriter

  @param sw: Script writer

  @type scriptname: string

  @param scriptname: Name of command line program

  @type funcname: string

  @param funcname: Shell function name

  @type commands: list

  @param commands: List of all subcommands in this program

  """

  sw.Write("%s() {", funcname)

  sw.IncIndent()

  try:

    sw.Write("local "

             ' cur="${COMP_WORDS[COMP_CWORD]}"'

             ' prev="${COMP_WORDS[COMP_CWORD-1]}"'

             ' i first_arg_idx choices compgenargs arg_idx')

    # Useful for debugging:

    #sw.Write("echo cur=\"$cur\" prev=\"$prev\"")

    #sw.Write("set | grep ^COMP_")

    sw.Write("COMPREPLY=()")

    if opts is not None and args is not None:

      assert not commands

      CompletionWriter(0, opts, args).WriteTo(sw)

    else:

      sw.Write("""if [[ "$COMP_CWORD" == 1 ]]; then""")

      sw.IncIndent()

      try:

        # Complete the command name

        WriteCompReply(sw,

                       ("-W %s" %

                        utils.ShellQuote(" ".join(sorted(commands.keys())))))

      finally:

        sw.DecIndent()

      sw.Write("fi")

      # We're doing options and arguments to commands

      sw.Write("""case "${COMP_WORDS[1]}" in""")

      for cmd, (_, argdef, optdef, _, _) in commands.iteritems():

        if not (argdef or optdef):

          continue

        # TODO: Group by arguments and options

        sw.Write("%s)", utils.ShellQuote(cmd))

        sw.IncIndent()

        try:

          CompletionWriter(1, optdef, argdef).WriteTo(sw)

        finally:

          sw.DecIndent()

        sw.Write(";;")

      sw.Write("esac")

  finally:

    sw.DecIndent()

  sw.Write("}")

  sw.Write("complete -F %s -o filenames %s",

           utils.ShellQuote(funcname),

           utils.ShellQuote(scriptname))

def GetFunctionName(name):

  return "_" + re.sub(r"[^a-z0-9]+", "_", name.lower())

def LoadModule(filename):

  """Loads an external module by filename.

  """

  (name, ext) = os.path.splitext(filename)

  fh = open(filename, "U")

  try:

    return imp.load_module(name, fh, filename, (ext, "U", imp.PY_SOURCE))

  finally:

    fh.close()

def GetCommands(filename, module):

  """Returns the commands defined in a module.

  Aliases are also added as commands.

  """

  try:

    commands = getattr(module, "commands")

  except AttributeError, err:

    raise Exception("Script %s doesn't have 'commands' attribute" %

                    filename)

  # Use aliases

  aliases = getattr(module, "aliases", {})

  if aliases:

    commands = commands.copy()

    for name, target in aliases.iteritems():

      commands[name] = commands[target]

  return commands

def main():

  buf = StringIO()

  sw = ShellWriter(buf)

  WritePreamble(sw)

  # gnt-* scripts

  for scriptname in _autoconf.GNT_SCRIPTS:

    filename = "scripts/%s" % scriptname

    WriteCompletion(sw, scriptname,

                    GetFunctionName(scriptname),

                    commands=GetCommands(filename, LoadModule(filename)))

  # Burnin script

  burnin = LoadModule("tools/burnin")

  WriteCompletion(sw, "%s/burnin" % constants.TOOLSDIR, "_ganeti_burnin",

                  opts=burnin.OPTIONS, args=burnin.ARGUMENTS)

  print buf.getvalue()

if __name__ == "__main__":

  main()