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 utils
30 from ganeti import errors
31 from ganeti import constants
34 def GetUserFiles(user, mkdir=False):
35 """Return the paths of a user's ssh files.
37 The function will return a triplet (priv_key_path, pub_key_path,
38 auth_key_path) that are used for ssh authentication. Currently, the
39 keys used are DSA keys, so this function will return:
40 (~user/.ssh/id_dsa, ~user/.ssh/id_dsa.pub,
41 ~user/.ssh/authorized_keys).
43 If the optional parameter mkdir is True, the ssh directory will be
44 created if it doesn't exist.
46 Regardless of the mkdir parameters, the script will raise an error
47 if ~user/.ssh is not a directory.
50 user_dir = utils.GetHomeDir(user)
52 raise errors.OpExecError("Cannot resolve home of user %s" % user)
54 ssh_dir = os.path.join(user_dir, ".ssh")
55 if not os.path.lexists(ssh_dir):
58 os.mkdir(ssh_dir, 0700)
59 except EnvironmentError, err:
60 raise errors.OpExecError("Can't create .ssh dir for user %s: %s" %
62 elif not os.path.isdir(ssh_dir):
63 raise errors.OpExecError("path ~%s/.ssh is not a directory" % user)
65 return [os.path.join(ssh_dir, base)
66 for base in ["id_dsa", "id_dsa.pub", "authorized_keys"]]
70 """Wrapper for SSH commands.
73 def __init__(self, cluster_name):
74 self.cluster_name = cluster_name
76 def _BuildSshOptions(self, batch, ask_key, use_cluster_key,
80 "-oHashKnownHosts=no",
81 "-oGlobalKnownHostsFile=%s" % constants.SSH_KNOWN_HOSTS_FILE,
82 "-oUserKnownHostsFile=/dev/null",
86 options.append("-oHostKeyAlias=%s" % self.cluster_name)
88 # TODO: Too many boolean options, maybe convert them to more descriptive
91 # Note: ask_key conflicts with batch mode
94 raise errors.ProgrammerError("SSH call requested conflicting options")
96 options.append("-oBatchMode=yes")
99 options.append("-oStrictHostKeyChecking=yes")
101 options.append("-oStrictHostKeyChecking=no")
105 "-oStrictHostKeyChecking=ask",
110 def BuildCmd(self, hostname, user, command, batch=True, ask_key=False,
111 tty=False, use_cluster_key=True, strict_host_check=True):
112 """Build an ssh command to execute a command on a remote node.
115 hostname: the target host, string
116 user: user to auth as
118 batch: if true, ssh will run in batch mode with no prompting
119 ask_key: if true, ssh will run with StrictHostKeyChecking=ask, so that
120 we can connect to an unknown host (not valid in batch mode)
121 use_cluster_key: Whether to expect and use the cluster-global SSH key
122 strict_host_check: Whether to check the host's SSH key at all
125 The ssh call to run 'command' on the remote host.
128 argv = [constants.SSH, "-q"]
129 argv.extend(self._BuildSshOptions(batch, ask_key, use_cluster_key,
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 logging.error("File %s must be an absolute path", filename)
166 if not os.path.isfile(filename):
167 logging.error("File %s does not exist", filename)
170 command = [constants.SCP, "-q", "-p"]
171 command.extend(self._BuildSshOptions(True, False, True, True))
172 command.append(filename)
173 command.append("%s:%s" % (node, filename))
175 result = utils.RunCmd(command)
178 logging.error("Copy to node %s failed (%s) error %s,"
180 node, result.fail_reason, result.output, result.cmd)
182 return not result.failed
184 def VerifyNodeHostname(self, node):
185 """Verify hostname consistency via SSH.
187 This functions connects via ssh to a node and compares the hostname
188 reported by the node to the name with have (the one that we
191 This is used to detect problems in ssh known_hosts files
192 (conflicting known hosts) and incosistencies between dns/hosts
193 entries and local machine names
196 node: nodename of a host to check. can be short or full qualified hostname
202 detail: String with details
205 retval = self.Run(node, 'root', 'hostname')
209 output = retval.output
211 msg += ": %s" % output
214 remotehostname = retval.stdout.strip()
216 if not remotehostname or remotehostname != node:
217 return False, "hostname mismatch, got %s" % remotehostname
219 return True, "host matches"
222 def WriteKnownHostsFile(cfg, file_name):
223 """Writes the cluster-wide equally known_hosts file.
226 utils.WriteFile(file_name, mode=0700,
227 data="%s ssh-rsa %s\n" % (cfg.GetClusterName(),