Source Code for Module ganeti.utils.nodesetup

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 29   
 30  """Utility functions for manipulating /etc/hosts. 
 31   
 32  """ 
 33   
 34  from cStringIO import StringIO 
 35   
 36  from ganeti import pathutils 
 37   
 38  from ganeti.utils import algo 
 39  from ganeti.utils import io 
 40   
 41   
 42 -def SetEtcHostsEntry(file_name, ip, hostname, aliases): 
 43    """Sets the name of an IP address and hostname in /etc/hosts. 
 44   
 45    @type file_name: str 
 46    @param file_name: path to the file to modify (usually C{/etc/hosts}) 
 47    @type ip: str 
 48    @param ip: the IP address 
 49    @type hostname: str 
 50    @param hostname: the hostname to be added 
 51    @type aliases: list 
 52    @param aliases: the list of aliases to add for the hostname 
 53   
 54    """ 
 55    # Ensure aliases are unique 
 56    names = algo.UniqueSequence([hostname] + aliases) 
 57   
 58    out = StringIO() 
 59   
 60    def _write_entry(written): 
 61      if not written: 
 62        out.write("%s\t%s\n" % (ip, " ".join(names))) 
 63      return True 
 64   
 65    written = False 
 66    for line in io.ReadFile(file_name).splitlines(True): 
 67      fields = line.split() 
 68      if fields and not fields[0].startswith("#") and ip == fields[0]: 
 69        written = _write_entry(written) 
 70      else: 
 71        out.write(line) 
 72    _write_entry(written) 
 73   
 74    io.WriteFile(file_name, data=out.getvalue(), uid=0, gid=0, mode=0644, 
 75                 keep_perms=io.KP_IF_EXISTS) 
 76   
 77   
 78 -def AddHostToEtcHosts(hostname, ip): 
 79    """Wrapper around SetEtcHostsEntry. 
 80   
 81    @type hostname: str 
 82    @param hostname: a hostname that will be resolved and added to 
 83        L{pathutils.ETC_HOSTS} 
 84    @type ip: str 
 85    @param ip: The ip address of the host 
 86   
 87    """ 
 88    SetEtcHostsEntry(pathutils.ETC_HOSTS, ip, hostname, [hostname.split(".")[0]]) 
 89   
 90   
 91 -def RemoveEtcHostsEntry(file_name, hostname): 
 92    """Removes a hostname from /etc/hosts. 
 93   
 94    IP addresses without names are removed from the file. 
 95   
 96    @type file_name: str 
 97    @param file_name: path to the file to modify (usually C{/etc/hosts}) 
 98    @type hostname: str 
 99    @param hostname: the hostname to be removed 
100   
101    """ 
102    out = StringIO() 
103   
104    for line in io.ReadFile(file_name).splitlines(True): 
105      fields = line.split() 
106      if len(fields) > 1 and not fields[0].startswith("#"): 
107        names = fields[1:] 
108        if hostname in names: 
109          while hostname in names: 
110            names.remove(hostname) 
111          if names: 
112            out.write("%s %s\n" % (fields[0], " ".join(names))) 
113          continue 
114   
115      out.write(line) 
116   
117    io.WriteFile(file_name, data=out.getvalue(), uid=0, gid=0, mode=0644, 
118                 keep_perms=io.KP_IF_EXISTS) 
119   
120   
121 -def RemoveHostFromEtcHosts(hostname): 
122    """Wrapper around RemoveEtcHostsEntry. 
123   
124    @type hostname: str 
125    @param hostname: hostname that will be resolved and its 
126        full and shot name will be removed from 
127        L{pathutils.ETC_HOSTS} 
128   
129    """ 
130    RemoveEtcHostsEntry(pathutils.ETC_HOSTS, hostname) 
131    RemoveEtcHostsEntry(pathutils.ETC_HOSTS, hostname.split(".")[0]) 
132