Synnefo » snf-image-creator

# Copyright 2012 GRNET S.A. All rights reserved.

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#      copyright notice, this list of conditions and the following

#      disclaimer.

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#   2. Redistributions in binary form must reproduce the above

#      copyright notice, this list of conditions and the following

#      disclaimer in the documentation and/or other materials

#      provided with the distribution.

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# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS

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# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

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import sys

import pbs

import hashlib

from colors import red, green, yellow

from progress.bar import Bar

class FatalError(Exception):

    pass

silent = False

def get_command(command):

    def find_sbin_command(command, exception):

        search_paths = ['/usr/local/sbin', '/usr/sbin', '/sbin']

        for fullpath in map(lambda x: "%s/%s" % (x, command), search_paths):

            if os.path.exists(fullpath) and os.access(fullpath, os.X_OK):

                return pbs.Command(fullpath)

        raise exception

    try:

        return pbs.__getattr__(command)

    except pbs.CommadNotFount as e:

        return find_sbin_command(command, e)

def error(msg, new_line=True):

    nl = "\n" if new_line else ''

    sys.stderr.write(red('Error: %s' % msg) + nl)

def warn(msg, new_line=True):

    if not silent:

        nl = "\n" if new_line else ''

        sys.stderr.write(yellow("Warning: %s" % msg) + nl)

def success(msg, new_line=True):

    if not silent:

        nl = "\n" if new_line else ''

        sys.stdout.write(green(msg) + nl)

        if not nl:

            sys.stdout.flush()

def output(msg="", new_line=True):

    if not silent:

        nl = "\n" if new_line else ''

        sys.stdout.write(msg + nl)

        if not nl:

            sys.stdout.flush()

def progress(message='', bar_type="default"):

    MESSAGE_LENGTH = 30

    suffix = {

        'default': '%(index)d/%(max)d',

        'percent': '%(percent)d%%',

        'b': '%(index)d/%(max)d B',

        'kb': '%(index)d/%(max)d KB',

        'mb': '%(index)d/%(max)d MB'

    }

    bar = Bar()

    bar.message = message.ljust(MESSAGE_LENGTH)

    bar.fill = '#'

    bar.suffix = suffix[bar_type]

    bar.bar_prefix = ' ['

    bar.bar_suffix = '] '

    return bar

def md5(filename, size):

    BLOCKSIZE = 2 ** 22  # 4MB

    progressbar = progress("Calculating md5sum:", 'mb')

    progressbar.max = (size // (2 ** 20))

    md5 = hashlib.md5()

    with open(filename, "r") as src:

        left = size

        while left > 0:

            length = min(left, BLOCKSIZE)

            data = src.read(length)

            md5.update(data)

            left -= length

            progressbar.goto((size - left) // (2 ** 20))

    checksum = md5.hexdigest()

    output("\rCalculating md5sum...\033[K", False)

    success(checksum)

    return checksum

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