Package paramiko :: Module config |
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# Source Code for Module paramiko.config

      1  # Copyright (C) 2006-2007  Robey Pointer <robeypointer@gmail.com>
      2  #
      3  # This file is part of paramiko.
      4  #
      5  # Paramiko is free software; you can redistribute it and/or modify it under the
      6  # terms of the GNU Lesser General Public License as published by the Free
      7  # Software Foundation; either version 2.1 of the License, or (at your option)
      8  # any later version.
      9  #
     10  # Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY
     11  # WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
     12  # A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
     13  # details.
     14  #
     15  # You should have received a copy of the GNU Lesser General Public License
     16  # along with Paramiko; if not, write to the Free Software Foundation, Inc.,
     17  # 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
     18
     19  """
     20  L{SSHConfig}.
     21  """
     22
     23  import fnmatch
     24
     25
     26 -class SSHConfig (object):
     27      """
     28      Representation of config information as stored in the format used by
     29      OpenSSH. Queries can be made via L{lookup}. The format is described in
     30      OpenSSH's C{ssh_config} man page. This class is provided primarily as a
     31      convenience to posix users (since the OpenSSH format is a de-facto
     32      standard on posix) but should work fine on Windows too.
     33
     34      @since: 1.6
     35      """
     36
     37 -    def __init__(self):
     38          """
     39          Create a new OpenSSH config object.
     40          """
     41          self._config = [ { 'host': '*' } ]
     42
     43 -    def parse(self, file_obj):
     44          """
     45          Read an OpenSSH config from the given file object.
     46
     47          @param file_obj: a file-like object to read the config file from
     48          @type file_obj: file
     49          """
     50          configs = [self._config[0]]
     51          for line in file_obj:
     52              line = line.rstrip('\n').lstrip()
     53              if (line == '') or (line[0] == '#'):
     54                  continue
     55              if '=' in line:
     56                  key, value = line.split('=', 1)
     57                  key = key.strip().lower()
     58              else:
     59                  # find first whitespace, and split there
     60                  i = 0
     61                  while (i < len(line)) and not line[i].isspace():
     62                      i += 1
     63                  if i == len(line):
     64                      raise Exception('Unparsable line: %r' % line)
     65                  key = line[:i].lower()
     66                  value = line[i:].lstrip()
     67
     68              if key == 'host':
     69                  del configs[:]
     70                  # the value may be multiple hosts, space-delimited
     71                  for host in value.split():
     72                      # do we have a pre-existing host config to append to?
     73                      matches = [c for c in self._config if c['host'] == host]
     74                      if len(matches) > 0:
     75                          configs.append(matches[0])
     76                      else:
     77                          config = { 'host': host }
     78                          self._config.append(config)
     79                          configs.append(config)
     80              else:
     81                  for config in configs:
     82                      config[key] = value
     83
     84 -    def lookup(self, hostname):
     85          """
     86          Return a dict of config options for a given hostname.
     87
     88          The host-matching rules of OpenSSH's C{ssh_config} man page are used,
     89          which means that all configuration options from matching host
     90          specifications are merged, with more specific hostmasks taking
     91          precedence. In other words, if C{"Port"} is set under C{"Host *"}
     92          and also C{"Host *.example.com"}, and the lookup is for
     93          C{"ssh.example.com"}, then the port entry for C{"Host *.example.com"}
     94          will win out.
     95
     96          The keys in the returned dict are all normalized to lowercase (look for
     97          C{"port"}, not C{"Port"}. No other processing is done to the keys or
     98          values.
     99
    100          @param hostname: the hostname to lookup
    101          @type hostname: str
    102          """
    103          matches = [x for x in self._config if fnmatch.fnmatch(hostname, x['host'])]
    104          # sort in order of shortest match (usually '*') to longest
    105          matches.sort(lambda x,y: cmp(len(x['host']), len(y['host'])))
    106          ret = {}
    107          for m in matches:
    108              ret.update(m)
    109          del ret['host']
    110          return ret
    111