Synnefo » snf-ganeti

#

#

# Copyright (C) 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.

"""Utilities for QA tests.

"""

import os

import sys

import subprocess

from ganeti import utils

import qa_config

import qa_error

_INFO_SEQ = None

_WARNING_SEQ = None

_ERROR_SEQ = None

_RESET_SEQ = None

# List of all hooks

_hooks = []

def _SetupColours():

  """Initializes the colour constants.

  """

  global _INFO_SEQ, _WARNING_SEQ, _ERROR_SEQ, _RESET_SEQ

  # Don't use colours if stdout isn't a terminal

  if not sys.stdout.isatty():

    return

  try:

    import curses

  except ImportError:

    # Don't use colours if curses module can't be imported

    return

  curses.setupterm()

  _RESET_SEQ = curses.tigetstr("op")

  setaf = curses.tigetstr("setaf")

  _INFO_SEQ = curses.tparm(setaf, curses.COLOR_GREEN)

  _WARNING_SEQ = curses.tparm(setaf, curses.COLOR_YELLOW)

  _ERROR_SEQ = curses.tparm(setaf, curses.COLOR_RED)

_SetupColours()

def AssertEqual(first, second):

  """Raises an error when values aren't equal.

  """

  if not first == second:

    raise qa_error.Error('%r == %r' % (first, second))

def AssertNotEqual(first, second):

  """Raises an error when values are equal.

  """

  if not first != second:

    raise qa_error.Error('%r != %r' % (first, second))

def GetSSHCommand(node, cmd, strict=True):

  """Builds SSH command to be executed.

  Args:

  - node: Node the command should run on

  - cmd: Command to be executed as a list with all parameters

  - strict: Whether to enable strict host key checking

  """

  args = [ 'ssh', '-oEscapeChar=none', '-oBatchMode=yes', '-l', 'root' ]

  if strict:

    tmp = 'yes'

  else:

    tmp = 'no'

  args.append('-oStrictHostKeyChecking=%s' % tmp)

  args.append('-oClearAllForwardings=yes')

  args.append('-oForwardAgent=yes')

  args.append(node)

  if qa_config.options.dry_run:

    prefix = 'exit 0; '

  else:

    prefix = ''

  args.append(prefix + cmd)

  print 'SSH:', utils.ShellQuoteArgs(args)

  return args

def StartSSH(node, cmd, strict=True):

  """Starts SSH.

  """

  return subprocess.Popen(GetSSHCommand(node, cmd, strict=strict),

                          shell=False)

def GetCommandOutput(node, cmd):

  """Returns the output of a command executed on the given node.

  """

  p = subprocess.Popen(GetSSHCommand(node, cmd),

                       shell=False, stdout=subprocess.PIPE)

  AssertEqual(p.wait(), 0)

  return p.stdout.read()

def UploadFile(node, src):

  """Uploads a file to a node and returns the filename.

  Caller needs to remove the returned file on the node when it's not needed

  anymore.

  """

  # Make sure nobody else has access to it while preserving local permissions

  mode = os.stat(src).st_mode & 0700

  cmd = ('tmp=$(tempfile --mode %o --prefix gnt) && '

         '[[ -f "${tmp}" ]] && '

         'cat > "${tmp}" && '

         'echo "${tmp}"') % mode

  f = open(src, 'r')

  try:

    p = subprocess.Popen(GetSSHCommand(node, cmd), shell=False, stdin=f,

                         stdout=subprocess.PIPE)

    AssertEqual(p.wait(), 0)

    # Return temporary filename

    return p.stdout.read().strip()

  finally:

    f.close()

def _ResolveName(cmd, key):

  """Helper function.

  """

  master = qa_config.GetMasterNode()

  output = GetCommandOutput(master['primary'], utils.ShellQuoteArgs(cmd))

  for line in output.splitlines():

    (lkey, lvalue) = line.split(':', 1)

    if lkey == key:

      return lvalue.lstrip()

  raise KeyError("Key not found")

def ResolveInstanceName(instance):

  """Gets the full name of an instance.

  """

  return _ResolveName(['gnt-instance', 'info', instance['name']],

                      'Instance name')

def ResolveNodeName(node):

  """Gets the full name of a node.

  """

  return _ResolveName(['gnt-node', 'info', node['primary']],

                      'Node name')

def GetNodeInstances(node, secondaries=False):

  """Gets a list of instances on a node.

  """

  master = qa_config.GetMasterNode()

  node_name = ResolveNodeName(node)

  # Get list of all instances

  cmd = ['gnt-instance', 'list', '--separator=:', '--no-headers',

         '--output=name,pnode,snodes']

  output = GetCommandOutput(master['primary'], utils.ShellQuoteArgs(cmd))

  instances = []

  for line in output.splitlines():

    (name, pnode, snodes) = line.split(':', 2)

    if ((not secondaries and pnode == node_name) or

        (secondaries and node_name in snodes.split(','))):

      instances.append(name)

  return instances

def _FormatWithColor(text, seq):

  if not seq:

    return text

  return "%s%s%s" % (seq, text, _RESET_SEQ)

FormatWarning = lambda text: _FormatWithColor(text, _WARNING_SEQ)

FormatError = lambda text: _FormatWithColor(text, _ERROR_SEQ)

FormatInfo = lambda text: _FormatWithColor(text, _INFO_SEQ)

def LoadHooks():

  """Load all QA hooks.

  """

  hooks_dir = qa_config.get('options', {}).get('hooks-dir', None)

  if not hooks_dir:

    return

  if hooks_dir not in sys.path:

    sys.path.insert(0, hooks_dir)

  for name in utils.ListVisibleFiles(hooks_dir):

    if name.endswith('.py'):

      # Load and instanciate hook

      print "Loading hook %s" % name

      _hooks.append(__import__(name[:-3], None, None, ['']).hook())

class QaHookContext:

  """Definition of context passed to hooks.

  """

  name = None

  phase = None

  success = None

  args = None

  kwargs = None

def _CallHooks(ctx):

  """Calls all hooks with the given context.

  """

  if not _hooks:

    return

  name = "%s-%s" % (ctx.phase, ctx.name)

  if ctx.success is not None:

    msg = "%s (success=%s)" % (name, ctx.success)

  else:

    msg = name

  print FormatInfo("Begin %s" % msg)

  for hook in _hooks:

    hook.run(ctx)

  print FormatInfo("End %s" % name)

def DefineHook(name):

  """Wraps a function with calls to hooks.

  Usage: prefix function with @qa_utils.DefineHook(...)

  This is based on PEP 318, "Decorators for Functions and Methods".

  """

  def wrapper(fn):

    def new_f(*args, **kwargs):

      # Create context

      ctx = QaHookContext()

      ctx.name = name

      ctx.phase = 'pre'

      ctx.args = args

      ctx.kwargs = kwargs

      _CallHooks(ctx)

      try:

        ctx.phase = 'post'

        ctx.success = True

        try:

          # Call real function

          return fn(*args, **kwargs)

        except:

          ctx.success = False

          raise

      finally:

        _CallHooks(ctx)

    # Override function metadata

    new_f.func_name = fn.func_name

    new_f.func_doc = fn.func_doc

    return new_f

  return wrapper