1 # -*- coding: utf-8 -*-
3 # Copyright 2012 GRNET S.A. All rights reserved.
5 # Redistribution and use in source and binary forms, with or
6 # without modification, are permitted provided that the following
9 # 1. Redistributions of source code must retain the above
10 # copyright notice, this list of conditions and the following
13 # 2. Redistributions in binary form must reproduce the above
14 # copyright notice, this list of conditions and the following
15 # disclaimer in the documentation and/or other materials
16 # provided with the distribution.
18 # THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
19 # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20 # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 # PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
22 # CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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26 # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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31 # The views and conclusions contained in the software and
32 # documentation are those of the authors and should not be
33 # interpreted as representing official policies, either expressed
34 # or implied, of GRNET S.A.
36 """This module provides various helper functions to be used by other parts of
47 class FatalError(Exception):
48 """Fatal Error exception of snf-image-creator"""
52 def get_command(command):
53 """Return a file system binary command"""
54 def find_sbin_command(command, exception):
55 search_paths = ['/usr/local/sbin', '/usr/sbin', '/sbin']
56 for fullpath in map(lambda x: "%s/%s" % (x, command), search_paths):
57 if os.path.exists(fullpath) and os.access(fullpath, os.X_OK):
58 return sh.Command(fullpath)
62 return sh.__getattr__(command)
63 except sh.CommandNotFound as e:
64 return find_sbin_command(command, e)
68 """Returns the path to the kvm binary and some extra arguments if needed"""
70 uname = get_command('uname')
71 which = get_command('which')
73 machine = str(uname('-m')).strip()
74 if re.match('i[3-6]86', machine):
77 binary = which('qemu-system-%s' % machine)
79 needed_args = "--enable-kvm",
82 return which('kvm'), tuple()
84 return binary, needed_args
87 def try_fail_repeat(command, *args):
88 """Execute a command multiple times until it succeeds"""
89 times = (0.1, 0.5, 1, 2)
95 except sh.ErrorReturnCode:
102 raise FatalError("Command: `%s %s' failed" % (command, " ".join(args)))
105 def free_space(dirname):
106 """Compute the free space in a directory"""
107 stat = os.statvfs(dirname)
108 return stat.f_bavail * stat.f_frsize
111 def check_guestfs_version(ghandler, major, minor, release):
112 """Checks if the version of the used libguestfs is smaller, equal or
113 greater than the one specified by the major, minor and release triplet
116 < 0 if the installed version is smaller than the specified one
117 = 0 if they are equal
118 > 0 if the installed one is greater than the specified one
121 ver = ghandler.version()
123 for (a, b) in (ver['major'], major), (ver['minor'], minor), \
124 (ver['release'], release):
132 """Represents MD5 computations"""
133 def __init__(self, output):
134 """Create an MD5 instance"""
137 def compute(self, filename, size):
138 """Compute the MD5 checksum of a file"""
140 BLOCKSIZE = 4 * MB # 4MB
142 prog_size = ((size + MB - 1) // MB) # in MB
143 progressbar = self.out.Progress(prog_size, "Calculating md5sum", 'mb')
145 with open(filename, "r") as src:
148 length = min(left, BLOCKSIZE)
149 data = src.read(length)
152 progressbar.goto((size - left) // MB)
154 checksum = md5.hexdigest()
155 progressbar.success(checksum)
159 # vim: set sta sts=4 shiftwidth=4 sw=4 et ai :