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
36 def GetUserFiles(user, mkdir=False):
37 """Return the paths of a user's ssh files.
39 The function will return a triplet (priv_key_path, pub_key_path,
40 auth_key_path) that are used for ssh authentication. Currently, the
41 keys used are DSA keys, so this function will return:
42 (~user/.ssh/id_dsa, ~user/.ssh/id_dsa.pub,
43 ~user/.ssh/authorized_keys).
45 If the optional parameter mkdir is True, the ssh directory will be
46 created if it doesn't exist.
48 Regardless of the mkdir parameters, the script will raise an error
49 if ~user/.ssh is not a directory.
52 user_dir = utils.GetHomeDir(user)
54 raise errors.OpExecError("Cannot resolve home of user %s" % user)
56 ssh_dir = os.path.join(user_dir, ".ssh")
57 if not os.path.lexists(ssh_dir):
60 os.mkdir(ssh_dir, 0700)
61 except EnvironmentError, err:
62 raise errors.OpExecError("Can't create .ssh dir for user %s: %s" %
64 elif not os.path.isdir(ssh_dir):
65 raise errors.OpExecError("path ~%s/.ssh is not a directory" % user)
67 return [os.path.join(ssh_dir, base)
68 for base in ["id_dsa", "id_dsa.pub", "authorized_keys"]]
72 """Wrapper for SSH commands.
75 def __init__(self, sstore=None):
77 self.sstore = ssconf.SimpleStore()
81 def _BuildSshOptions(self, batch, ask_key, use_cluster_key,
85 "-oHashKnownHosts=no",
86 "-oGlobalKnownHostsFile=%s" % constants.SSH_KNOWN_HOSTS_FILE,
87 "-oUserKnownHostsFile=/dev/null",
91 options.append("-oHostKeyAlias=%s" % self.sstore.GetClusterName())
93 # TODO: Too many boolean options, maybe convert them to more descriptive
96 # Note: ask_key conflicts with batch mode
99 raise errors.ProgrammerError("SSH call requested conflicting options")
101 options.append("-oBatchMode=yes")
103 if strict_host_check:
104 options.append("-oStrictHostKeyChecking=yes")
106 options.append("-oStrictHostKeyChecking=no")
110 "-oStrictHostKeyChecking=ask",
115 def BuildCmd(self, hostname, user, command, batch=True, ask_key=False,
116 tty=False, use_cluster_key=True, strict_host_check=True):
117 """Build an ssh command to execute a command on a remote node.
120 hostname: the target host, string
121 user: user to auth as
123 batch: if true, ssh will run in batch mode with no prompting
124 ask_key: if true, ssh will run with StrictHostKeyChecking=ask, so that
125 we can connect to an unknown host (not valid in batch mode)
126 use_cluster_key: Whether to expect and use the cluster-global SSH key
127 strict_host_check: Whether to check the host's SSH key at all
130 The ssh call to run 'command' on the remote host.
133 argv = [constants.SSH, "-q"]
134 argv.extend(self._BuildSshOptions(batch, ask_key, use_cluster_key,
138 argv.extend(["%s@%s" % (user, hostname), command])
141 def Run(self, *args, **kwargs):
142 """Runs a command on a remote node.
144 This method has the same return value as `utils.RunCmd()`, which it
148 See SshRunner.BuildCmd.
151 `utils.RunResult` like `utils.RunCmd()`
154 return utils.RunCmd(self.BuildCmd(*args, **kwargs))
156 def CopyFileToNode(self, node, filename):
157 """Copy a file to another node with scp.
160 node: node in the cluster
161 filename: absolute pathname of a local file
167 if not os.path.isabs(filename):
168 logger.Error("file %s must be an absolute path" % (filename))
171 if not os.path.isfile(filename):
172 logger.Error("file %s does not exist" % (filename))
175 command = [constants.SCP, "-q", "-p"]
176 command.extend(self._BuildSshOptions(True, False, True, True))
177 command.append(filename)
178 command.append("%s:%s" % (node, filename))
180 result = utils.RunCmd(command)
183 logger.Error("copy to node %s failed (%s) error %s,"
185 (node, result.fail_reason, result.output, result.cmd))
187 return not result.failed
189 def VerifyNodeHostname(self, node):
190 """Verify hostname consistency via SSH.
192 This functions connects via ssh to a node and compares the hostname
193 reported by the node to the name with have (the one that we
196 This is used to detect problems in ssh known_hosts files
197 (conflicting known hosts) and incosistencies between dns/hosts
198 entries and local machine names
201 node: nodename of a host to check. can be short or full qualified hostname
207 detail: String with details
210 retval = self.Run(node, 'root', 'hostname')
214 output = retval.output
216 msg += ": %s" % output
219 remotehostname = retval.stdout.strip()
221 if not remotehostname or remotehostname != node:
222 return False, "hostname mismatch, got %s" % remotehostname
224 return True, "host matches"
227 def WriteKnownHostsFile(cfg, sstore, file_name):
228 """Writes the cluster-wide equally known_hosts file.
231 utils.WriteFile(file_name, mode=0700,
232 data="%s ssh-rsa %s\n" % (sstore.GetClusterName(),