pykickstart/version.py

   1 #
   2 # Chris Lumens <clumens@redhat.com>
   3 #
   4 # Copyright 2006, 2007, 2008 Red Hat, Inc.
   5 #
   6 # This copyrighted material is made available to anyone wishing to use, modify,
   7 # copy, or redistribute it subject to the terms and conditions of the GNU
   8 # General Public License v.2.  This program is distributed in the hope that it
   9 # will be useful, but WITHOUT ANY WARRANTY expressed or implied, including the
  10 # implied warranties of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11 # See the GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License along with
  14 # this program; if not, write to the Free Software Foundation, Inc., 51
  15 # Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  Any Red Hat
  16 # trademarks that are incorporated in the source code or documentation are not
  17 # subject to the GNU General Public License and may only be used or replicated
  18 # with the express permission of Red Hat, Inc.
  19 #
  20 """
  21 Methods for working with kickstart versions.
  22
  23 This module defines several symbolic constants that specify kickstart syntax
  24 versions.  Each version corresponds roughly to one release of Red Hat Linux,
  25 Red Hat Enterprise Linux, or Fedora Core as these are where most syntax
  26 changes take place.
  27
  28 This module also exports several functions:
  29
  30     makeVersion - Given a version number, return an instance of the
  31                   matching handler class.
  32
  33     returnClassForVersion - Given a version number, return the matching
  34                             handler class.  This does not return an
  35                             instance of that class, however.
  36
  37     stringToVersion - Convert a string representation of a version number
  38                       into the symbolic constant.
  39
  40     versionToString - Perform the reverse mapping.
  41
  42     versionFromFile - Read a kickstart file and determine the version of
  43                       syntax it uses.  This requires the kickstart file to
  44                       have a version= comment in it.
  45 """
  46 import imputil, re, sys
  47 from urlgrabber import urlopen
  48
  49 from rhpl.translate import _
  50 from pykickstart.errors import KickstartVersionError
  51
  52 # Symbolic names for internal version numbers.
  53 RHEL3 = 900
  54 FC3 = 1000
  55 RHEL4 = 1100
  56 FC4 = 2000
  57 FC5 = 3000
  58 FC6 = 4000
  59 RHEL5 = 4100
  60 F7  = 5000
  61 F8 = 6000
  62 F9 = 7000
  63 F10 = 8000
  64
  65 # This always points at the latest version and is the default.
  66 DEVEL = F10
  67
  68 """A one-to-one mapping from string representations to version numbers."""
  69 versionMap = {
  70         "DEVEL": DEVEL,
  71         "FC3": FC3, "FC4": FC4, "FC5": FC5, "FC6": FC6, "F7": F7, "F8": F8,
  72         "F9": F9, "F10": F10,
  73         "RHEL3": RHEL3, "RHEL4": RHEL4, "RHEL5": RHEL5
  74 }
  75
  76 def stringToVersion(s):
  77     """Convert string into one of the provided version constants.  Raises
  78        KickstartVersionError if string does not match anything.
  79     """
  80     # First try these short forms.
  81     try:
  82         return versionMap[s.upper()]
  83     except KeyError:
  84         pass
  85
  86     # Now try the Fedora versions.
  87     m = re.match("^fedora.* (\d)+$", s, re.I)
  88
  89     if m and m.group(1):
  90         if versionMap.has_key("FC" + m.group(1)):
  91             return versionMap["FC" + m.group(1)]
  92         elif versionMap.has_key("F" + m.group(1)):
  93             return versionMap["F" + m.group(1)]
  94         else:
  95             raise KickstartVersionError(_("Unsupported version specified: %s") % s)
  96
  97     # Now try the RHEL versions.
  98     m = re.match("^red hat enterprise linux.* (\d)+$", s, re.I)
  99
 100     if m and m.group(1):
 101         if versionMap.has_key("RHEL" + m.group(1)):
 102             return versionMap["RHEL" + m.group(1)]
 103         else:
 104             raise KickstartVersionError(_("Unsupported version specified: %s") % s)
 105
 106     # If nothing else worked, we're out of options.
 107     raise KickstartVersionError(_("Unsupported version specified: %s") % s)
 108
 109 def versionToString(version, skipDevel=False):
 110     """Convert version into a string representation of the version number.
 111        This is the reverse operation of stringToVersion.  Raises
 112        KickstartVersionError if version does not match anything.
 113     """
 114     for (key, val) in versionMap.iteritems():
 115         if version == DEVEL and key == "DEVEL" and skipDevel:
 116             continue
 117
 118         if val == version:
 119             return key
 120
 121     raise KickstartVersionError(_("Unsupported version specified: %s") % version)
 122
 123 def versionFromFile(f):
 124     """Given a file or URL, look for a line starting with #version= and
 125        return the version number.  If no version is found, return DEVEL.
 126     """
 127     v = DEVEL
 128
 129     fh = urlopen(f)
 130
 131     while True:
 132         try:
 133             l = fh.readline()
 134         except StopIteration:
 135             break
 136
 137         # At the end of the file?
 138         if l == "":
 139             break
 140
 141         if l.isspace() or l.strip() == "":
 142             continue
 143
 144         if l[:9] == "#version=":
 145             v = stringToVersion(l[9:].rstrip())
 146             break
 147
 148     fh.close()
 149     return v
 150
 151 def returnClassForVersion(version=DEVEL):
 152     """Return the class of the syntax handler for version.  version can be
 153        either a string or the matching constant.  Raises KickstartValueError
 154        if version does not match anything.
 155     """
 156     try:
 157         version = int(version)
 158         module = "%s" % versionToString(version, skipDevel=True)
 159     except ValueError:
 160         module = "%s" % version
 161         version = stringToVersion(version)
 162
 163     module = module.lower()
 164
 165     try:
 166         import pykickstart.handlers
 167         sys.path.extend(pykickstart.handlers.__path__)
 168         found = imputil.imp.find_module(module)
 169         loaded = imputil.imp.load_module(module, found[0], found[1], found[2])
 170
 171         for (k, v) in loaded.__dict__.iteritems():
 172             if k.find("Handler") != -1:
 173                 return v
 174     except:
 175         raise KickstartVersionError(_("Unsupported version specified: %s") % version)
 176
 177 def makeVersion(version=DEVEL):
 178     """Return a new instance of the syntax handler for version.  version can be
 179        either a string or the matching constant.  This function is useful for
 180        standalone programs which just need to handle a specific version of
 181        kickstart syntax (as provided by a command line argument, for example)
 182        and need to instantiate the correct object.
 183     """
 184     cl = returnClassForVersion(version)
 185     return cl()