4 # Copyright (C) 2006, 2007 Google Inc.
6 # This program is free software; you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation; either version 2 of the License, or
9 # (at your option) any later version.
11 # This program is distributed in the hope that it will be useful, but
12 # WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 # General Public License for more details.
16 # You should have received a copy of the GNU General Public License
17 # along with this program; if not, write to the Free Software
18 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
22 """Module encapsulating ssh functionality.
29 from ganeti import logger
30 from ganeti import utils
31 from ganeti import errors
32 from ganeti import constants
33 from ganeti import ssconf
37 "-oGlobalKnownHostsFile=%s" % constants.SSH_KNOWN_HOSTS_FILE,
38 "-oUserKnownHostsFile=/dev/null",
41 # Note: BATCH_MODE conflicts with ASK_KEY
45 "-oStrictHostKeyChecking=yes",
50 "-oHashKnownHosts=no",
51 "-oStrictHostKeyChecking=ask",
55 def GetUserFiles(user, mkdir=False):
56 """Return the paths of a user's ssh files.
58 The function will return a triplet (priv_key_path, pub_key_path,
59 auth_key_path) that are used for ssh authentication. Currently, the
60 keys used are DSA keys, so this function will return:
61 (~user/.ssh/id_dsa, ~user/.ssh/id_dsa.pub,
62 ~user/.ssh/authorized_keys).
64 If the optional parameter mkdir is True, the ssh directory will be
65 created if it doesn't exist.
67 Regardless of the mkdir parameters, the script will raise an error
68 if ~user/.ssh is not a directory.
71 user_dir = utils.GetHomeDir(user)
73 raise errors.OpExecError("Cannot resolve home of user %s" % user)
75 ssh_dir = os.path.join(user_dir, ".ssh")
76 if not os.path.lexists(ssh_dir):
79 os.mkdir(ssh_dir, 0700)
80 except EnvironmentError, err:
81 raise errors.OpExecError("Can't create .ssh dir for user %s: %s" %
83 elif not os.path.isdir(ssh_dir):
84 raise errors.OpExecError("path ~%s/.ssh is not a directory" % user)
86 return [os.path.join(ssh_dir, base)
87 for base in ["id_dsa", "id_dsa.pub", "authorized_keys"]]
91 """Wrapper for SSH commands.
94 def __init__(self, sstore=None):
96 self.sstore = ssconf.SimpleStore()
100 def _GetHostKeyAliasOption(self):
101 return "-oHostKeyAlias=%s" % self.sstore.GetClusterName()
103 def BuildCmd(self, hostname, user, command, batch=True, ask_key=False,
104 tty=False, use_cluster_key=True):
105 """Build an ssh command to execute a command on a remote node.
108 hostname: the target host, string
109 user: user to auth as
111 batch: if true, ssh will run in batch mode with no prompting
112 ask_key: if true, ssh will run with StrictHostKeyChecking=ask, so that
113 we can connect to an unknown host (not valid in batch mode)
114 use_cluster_key: Whether to expect and use the cluster-global SSH key
117 The ssh call to run 'command' on the remote host.
120 argv = [constants.SSH, "-q"]
121 argv.extend(KNOWN_HOSTS_OPTS)
123 argv.append(self._GetHostKeyAliasOption())
125 # if we are in batch mode, we can't ask the key
127 raise errors.ProgrammerError("SSH call requested conflicting options")
128 argv.extend(BATCH_MODE_OPTS)
130 argv.extend(ASK_KEY_OPTS)
133 argv.extend(["%s@%s" % (user, hostname), command])
136 def Run(self, *args, **kwargs):
137 """Runs a command on a remote node.
139 This method has the same return value as `utils.RunCmd()`, which it
143 See SshRunner.BuildCmd.
146 `utils.RunResult` like `utils.RunCmd()`
149 return utils.RunCmd(self.BuildCmd(*args, **kwargs))
151 def CopyFileToNode(self, node, filename):
152 """Copy a file to another node with scp.
155 node: node in the cluster
156 filename: absolute pathname of a local file
162 if not os.path.isabs(filename):
163 logger.Error("file %s must be an absolute path" % (filename))
166 if not os.path.isfile(filename):
167 logger.Error("file %s does not exist" % (filename))
170 command = [constants.SCP, "-q", "-p"]
171 command.extend(KNOWN_HOSTS_OPTS)
172 command.extend(BATCH_MODE_OPTS)
173 command.append(self._GetHostKeyAliasOption())
174 command.append(filename)
175 command.append("%s:%s" % (node, filename))
177 result = utils.RunCmd(command)
180 logger.Error("copy to node %s failed (%s) error %s,"
182 (node, result.fail_reason, result.output, result.cmd))
184 return not result.failed
186 def VerifyNodeHostname(self, node):
187 """Verify hostname consistency via SSH.
189 This functions connects via ssh to a node and compares the hostname
190 reported by the node to the name with have (the one that we
193 This is used to detect problems in ssh known_hosts files
194 (conflicting known hosts) and incosistencies between dns/hosts
195 entries and local machine names
198 node: nodename of a host to check. can be short or full qualified hostname
204 detail: String with details
207 retval = self.Run(node, 'root', 'hostname')
211 output = retval.output
213 msg += ": %s" % output
216 remotehostname = retval.stdout.strip()
218 if not remotehostname or remotehostname != node:
219 return False, "hostname mismatch, got %s" % remotehostname
221 return True, "host matches"
224 def WriteKnownHostsFile(cfg, sstore, file_name):
225 """Writes the cluster-wide equally known_hosts file.
228 utils.WriteFile(file_name, mode=0700,
229 data="%s ssh-rsa %s\n" % (sstore.GetClusterName(),