## helpers.py
## Implement policies required for the sos system support tool
## Copyright (C) 2006 Steve Conklin <sconklin@redhat.com>
### 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., 675 Mass Ave, Cambridge, MA 02139, USA.
## Some code adapted from "Python Cookbook, 2nd ed", by Alex
## Martelli, Anna Martelli Ravenscroft, and David Ascher
## (O'Reilly Media, 2005) 0-596-00797-3
##
"""
helper functions used by sosreport and plugins
"""
import os, popen2, fcntl, select, itertools, sys, commands
from time import time
from tempfile import mkdtemp
def importPlugin(pluginname, name):
""" Import a plugin to extend capabilities of sosreport
"""
try:
plugin = __import__(pluginname, globals(), locals(), [name])
except ImportError:
return None
return getattr(plugin, name)
def sosFindTmpDir():
"""Find a temp directory to form the root for our gathered information
and reports.
"""
workingBase = mkdtemp("","sos_")
return workingBase
def makeNonBlocking(afd):
""" Make the file descriptor non-blocking. This prevents deadlocks.
"""
fl = fcntl.fcntl(afd, fcntl.F_GETFL)
try:
fcntl.fcntl(afd, fcntl.F_SETFL, fl | os.O_NDELAY)
except AttributeError:
fcntl.fcntl(afd, fcntl.F_SETFL, fl | os.FNDELAY)
def sosGetCommandOutput(command):
""" Execute a command and gather stdin, stdout, and return status.
Adapted from Python Cookbook - O'Reilly
"""
stime = time()
errdata = ''
status,outdata=commands.getstatusoutput(command)
return (status, outdata, time()-stime)
# FIXME: this needs to be made clean and moved to the plugin tools, so
# that it prints nice color output like sysreport if the progress bar
# is not enabled.
def sosStatus(stat):
""" Complete a status line that has been output to the console,
providing pass/fail indication.
"""
if not stat:
print " [ OK ]"
else:
print " [ FAILED ]"
sys.stdout.flush()
return
def allEqual(elements):
''' return True if all the elements are equal, otherwise False. '''
first_element = elements[0]
for other_element in elements[1:]:
if other_element != first_element:
return False
return True
def commonPrefix(*sequences):
''' return a list of common elements at the start of all sequences,
then a list of lists that are the unique tails of each sequence. '''
# if there are no sequences at all, we're done
if not sequences:
return [], []
# loop in parallel on the sequences
common = []
for elements in itertools.izip(*sequences):
# unless all elements are equal, bail out of the loop
if not allEqual(elements):
break
# got one more common element, append it and keep looping
common.append(elements[0])
# return the common prefix and unique tails
return common, [ sequence[len(common):] for sequence in sequences ]
def sosRelPath(path1, path2, sep=os.path.sep, pardir=os.path.pardir):
''' return a relative path from path1 equivalent to path path2.
In particular: the empty string, if path1 == path2;
path2, if path1 and path2 have no common prefix.
'''
common, (u1, u2) = commonPrefix(path1.split(sep), path2.split(sep))
if not common:
return path2 # leave path absolute if nothing at all in common
return sep.join( [pardir]*len(u1) + u2 )
