Convert check_guestfs_version into an Image method

[snf-image-creator] / image_creator / util.py

diff --git a/image_creator/util.py b/image_creator/util.py
index b4d5000..4e1b706 100644 (file)
--- a/image_creator/util.py
+++ b/image_creator/util.py
@@ -1,3 +1,5 @@
+# -*- coding: utf-8 -*-
+#

 # Copyright 2012 GRNET S.A. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or
 # Copyright 2012 GRNET S.A. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or

@@ -31,17 +33,24 @@
 # interpreted as representing official policies, either expressed
 # or implied, of GRNET S.A.
 
 # interpreted as representing official policies, either expressed
 # or implied, of GRNET S.A.
 

+"""This module provides various helper functions to be used by other parts of
+the package.
+"""
+

 import sh
 import hashlib
 import time
 import os
 import sh
 import hashlib
 import time
 import os

+import re

 
 
 class FatalError(Exception):
 
 
 class FatalError(Exception):

+    """Fatal Error exception of snf-image-creator"""

     pass
 
 
 def get_command(command):
     pass
 
 
 def get_command(command):

+    """Return a file system binary 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):
     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):

@@ -51,12 +60,32 @@ def get_command(command):
 
     try:
         return sh.__getattr__(command)
 
     try:
         return sh.__getattr__(command)

-    except sh.CommadNotFount as e:
+    except sh.CommandNotFound as e:

         return find_sbin_command(command, e)
 
 
         return find_sbin_command(command, e)
 
 

-def try_fail_repeat(command, *args):
+def get_kvm_binary():
+    """Returns the path to the kvm binary and some extra arguments if needed"""
+
+    uname = get_command('uname')
+    which = get_command('which')
+
+    machine = str(uname('-m')).strip()
+    if re.match('i[3-6]86', machine):
+        machine = 'i386'
+
+    binary = which('qemu-system-%s' % machine)

 
 

+    needed_args = "--enable-kvm",
+
+    if binary is None:
+        return which('kvm'), tuple()
+
+    return binary, needed_args
+
+
+def try_fail_repeat(command, *args):
+    """Execute a command multiple times until it succeeds"""

     times = (0.1, 0.5, 1, 2)
     i = iter(times)
     while True:
     times = (0.1, 0.5, 1, 2)
     i = iter(times)
     while True:

@@ -74,15 +103,19 @@ def try_fail_repeat(command, *args):
 
 
 def free_space(dirname):
 
 
 def free_space(dirname):

+    """Compute the free space in a directory"""

     stat = os.statvfs(dirname)
     return stat.f_bavail * stat.f_frsize
 
 
 class MD5:
     stat = os.statvfs(dirname)
     return stat.f_bavail * stat.f_frsize
 
 
 class MD5:

+    """Represents MD5 computations"""

     def __init__(self, output):
     def __init__(self, output):

+        """Create an MD5 instance"""

         self.out = output
 
     def compute(self, filename, size):
         self.out = output
 
     def compute(self, filename, size):

+        """Compute the MD5 checksum of a file"""

         MB = 2 ** 20
         BLOCKSIZE = 4 * MB  # 4MB
 
         MB = 2 ** 20
         BLOCKSIZE = 4 * MB  # 4MB