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  import os 
 25  import socket 
 26   
 27  SSH_PORT=22 
 28   
29 -class SSHConfig (object):
30 """ 31 Representation of config information as stored in the format used by 32 OpenSSH. Queries can be made via L{lookup}. The format is described in 33 OpenSSH's C{ssh_config} man page. This class is provided primarily as a 34 convenience to posix users (since the OpenSSH format is a de-facto 35 standard on posix) but should work fine on Windows too. 36 37 @since: 1.6 38 """ 39
40 - def __init__(self):
41 """ 42 Create a new OpenSSH config object. 43 """ 44 self._config = [ { 'host': '*' } ]
45
46 - def parse(self, file_obj):
47 """ 48 Read an OpenSSH config from the given file object. 49 50 @param file_obj: a file-like object to read the config file from 51 @type file_obj: file 52 """ 53 configs = [self._config[0]] 54 for line in file_obj: 55 line = line.rstrip('\n').lstrip() 56 if (line == '') or (line[0] == '#'): 57 continue 58 if '=' in line: 59 key, value = line.split('=', 1) 60 key = key.strip().lower() 61 else: 62 # find first whitespace, and split there 63 i = 0 64 while (i < len(line)) and not line[i].isspace(): 65 i += 1 66 if i == len(line): 67 raise Exception('Unparsable line: %r' % line) 68 key = line[:i].lower() 69 value = line[i:].lstrip() 70 71 if key == 'host': 72 del configs[:] 73 # the value may be multiple hosts, space-delimited 74 for host in value.split(): 75 # do we have a pre-existing host config to append to? 76 matches = [c for c in self._config if c['host'] == host] 77 if len(matches) > 0: 78 configs.append(matches[0]) 79 else: 80 config = { 'host': host } 81 self._config.append(config) 82 configs.append(config) 83 else: 84 for config in configs: 85 config[key] = value
86
87 - def lookup(self, hostname):
88 """ 89 Return a dict of config options for a given hostname. 90 91 The host-matching rules of OpenSSH's C{ssh_config} man page are used, 92 which means that all configuration options from matching host 93 specifications are merged, with more specific hostmasks taking 94 precedence. In other words, if C{"Port"} is set under C{"Host *"} 95 and also C{"Host *.example.com"}, and the lookup is for 96 C{"ssh.example.com"}, then the port entry for C{"Host *.example.com"} 97 will win out. 98 99 The keys in the returned dict are all normalized to lowercase (look for 100 C{"port"}, not C{"Port"}. No other processing is done to the keys or 101 values. 102 103 @param hostname: the hostname to lookup 104 @type hostname: str 105 """ 106 matches = [x for x in self._config if fnmatch.fnmatch(hostname, x['host'])] 107 # Move * to the end 108 _star = matches.pop(0) 109 matches.append(_star) 110 ret = {} 111 for m in matches: 112 for k,v in m.iteritems(): 113 if not k in ret: 114 ret[k] = v 115 ret = self._expand_variables(ret, hostname) 116 del ret['host'] 117 return ret
118
119 - def _expand_variables(self, config, hostname ):
120 """ 121 Return a dict of config options with expanded substitutions 122 for a given hostname. 123 124 Please refer to man ssh_config(5) for the parameters that 125 are replaced. 126 127 @param config: the config for the hostname 128 @type hostname: dict 129 @param hostname: the hostname that the config belongs to 130 @type hostname: str 131 """ 132 133 if 'hostname' in config: 134 config['hostname'] = config['hostname'].replace('%h',hostname) 135 else: 136 config['hostname'] = hostname 137 138 if 'port' in config: 139 port = config['port'] 140 else: 141 port = SSH_PORT 142 143 user = os.getenv('USER') 144 if 'user' in config: 145 remoteuser = config['user'] 146 else: 147 remoteuser = user 148 149 host = socket.gethostname().split('.')[0] 150 fqdn = socket.getfqdn() 151 homedir = os.path.expanduser('~') 152 replacements = {'controlpath' : 153 [ 154 ('%h', config['hostname']), 155 ('%l', fqdn), 156 ('%L', host), 157 ('%n', hostname), 158 ('%p', port), 159 ('%r', remoteuser), 160 ('%u', user) 161 ], 162 'identityfile' : 163 [ 164 ('~', homedir), 165 ('%d', homedir), 166 ('%h', config['hostname']), 167 ('%l', fqdn), 168 ('%u', user), 169 ('%r', remoteuser) 170 ] 171 } 172 for k in config: 173 if k in replacements: 174 for find, replace in replacements[k]: 175 config[k] = config[k].replace(find, str(replace)) 176 return config
177