Source Code for Module ganeti.utils.version

  1  # 
  2  # 
  3   
  4  # Copyright (C) 2013 Google Inc. 
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 29   
 30   
 31  """Version utilities.""" 
 32   
 33  import re 
 34   
 35  from ganeti import constants 
 36   
 37  _FULL_VERSION_RE = re.compile(r"(\d+)\.(\d+)\.(\d+)") 
 38  _SHORT_VERSION_RE = re.compile(r"(\d+)\.(\d+)") 
 39   
 40  # The first Ganeti version that supports automatic upgrades 
 41  FIRST_UPGRADE_VERSION = (2, 10, 0) 
 42   
 43  CURRENT_VERSION = (constants.VERSION_MAJOR, constants.VERSION_MINOR, 
 44                     constants.VERSION_REVISION) 
 45   
 46  # Format for CONFIG_VERSION: 
 47  #   01 03 0123 = 01030123 
 48  #   ^^ ^^ ^^^^ 
 49  #   |  |  + Configuration version/revision 
 50  #   |  + Minor version 
 51  #   + Major version 
 52  # 
 53  # It is stored as an integer. Make sure not to write an octal number. 
 54   
 55  # BuildVersion and SplitVersion must be in here because we can't import other 
 56  # modules. The cfgupgrade tool must be able to read and write version numbers 
 57  # and thus requires these functions. To avoid code duplication, they're kept in 
 58  # here. 
 59   
 60   
 61 -def BuildVersion(major, minor, revision): 
 62    """Calculates int version number from major, minor and revision numbers. 
 63   
 64    Returns: int representing version number 
 65   
 66    """ 
 67    assert isinstance(major, int) 
 68    assert isinstance(minor, int) 
 69    assert isinstance(revision, int) 
 70    return (1000000 * major + 
 71              10000 * minor + 
 72                  1 * revision) 
 73   
 74   
 75 -def SplitVersion(version): 
 76    """Splits version number stored in an int. 
 77   
 78    Returns: tuple; (major, minor, revision) 
 79   
 80    """ 
 81    assert isinstance(version, int) 
 82   
 83    (major, remainder) = divmod(version, 1000000) 
 84    (minor, revision) = divmod(remainder, 10000) 
 85   
 86    return (major, minor, revision) 
 87   
 88   
 89 -def ParseVersion(versionstring): 
 90    """Parses a version string. 
 91   
 92    @param versionstring: the version string to parse 
 93    @type versionstring: string 
 94    @rtype: tuple or None 
 95    @return: (major, minor, revision) if parsable, None otherwise. 
 96   
 97    """ 
 98    m = _FULL_VERSION_RE.match(versionstring) 
 99    if m is not None: 
100      return (int(m.group(1)), int(m.group(2)), int(m.group(3))) 
101   
102    m = _SHORT_VERSION_RE.match(versionstring) 
103    if m is not None: 
104      return (int(m.group(1)), int(m.group(2)), 0) 
105   
106    return None 
107   
108   
109 -def UpgradeRange(target, current=CURRENT_VERSION): 
110    """Verify whether a version is within the range of automatic upgrades. 
111   
112    @param target: The version to upgrade to as (major, minor, revision) 
113    @type target: tuple 
114    @param current: The version to upgrade from as (major, minor, revision) 
115    @type current: tuple 
116    @rtype: string or None 
117    @return: None, if within the range, and a human-readable error message 
118        otherwise 
119   
120    """ 
121    if target < FIRST_UPGRADE_VERSION or current < FIRST_UPGRADE_VERSION: 
122      return "automatic upgrades only supported from 2.10 onwards" 
123   
124    if target[0] != current[0]: 
125      return "different major versions" 
126   
127    if target[1] < current[1] - 1: 
128      return "can only downgrade one minor version at a time" 
129   
130    return None 
131   
132   
133 -def ShouldCfgdowngrade(version, current=CURRENT_VERSION): 
134    """Decide whether cfgupgrade --downgrade should be called. 
135   
136    Given the current version and the version to change to, decide 
137    if in the transition process cfgupgrade --downgrade should 
138    be called 
139   
140    @param version: The version to upgrade to as (major, minor, revision) 
141    @type version: tuple 
142    @param current: The version to upgrade from as (major, minor, revision) 
143    @type current: tuple 
144    @rtype: bool 
145    @return: True, if cfgupgrade --downgrade should be called. 
146   
147    """ 
148    return version[0] == current[0] and version[1] == current[1] - 1 
149   
150   
151 -def IsCorrectConfigVersion(targetversion, configversion): 
152    """Decide whether configuration version is compatible with the target. 
153   
154    @param targetversion: The version to upgrade to as (major, minor, revision) 
155    @type targetversion: tuple 
156    @param configversion: The version of the current configuration 
157    @type configversion: tuple 
158    @rtype: bool 
159    @return: True, if the configversion fits with the target version. 
160   
161    """ 
162    return (configversion[0] == targetversion[0] and 
163            configversion[1] == targetversion[1]) 
164