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2 | a8083063 | Iustin Pop | #
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3 | a8083063 | Iustin Pop | |
4 | a8083063 | Iustin Pop | # Copyright (C) 2006, 2007 Google Inc.
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5 | a8083063 | Iustin Pop | #
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6 | a8083063 | Iustin Pop | # This program is free software; you can redistribute it and/or modify
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7 | a8083063 | Iustin Pop | # it under the terms of the GNU General Public License as published by
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8 | a8083063 | Iustin Pop | # the Free Software Foundation; either version 2 of the License, or
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9 | a8083063 | Iustin Pop | # (at your option) any later version.
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10 | a8083063 | Iustin Pop | #
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11 | a8083063 | Iustin Pop | # This program is distributed in the hope that it will be useful, but
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12 | a8083063 | Iustin Pop | # WITHOUT ANY WARRANTY; without even the implied warranty of
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13 | a8083063 | Iustin Pop | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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14 | a8083063 | Iustin Pop | # General Public License for more details.
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15 | a8083063 | Iustin Pop | #
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16 | a8083063 | Iustin Pop | # You should have received a copy of the GNU General Public License
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17 | a8083063 | Iustin Pop | # along with this program; if not, write to the Free Software
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18 | a8083063 | Iustin Pop | # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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19 | a8083063 | Iustin Pop | # 02110-1301, USA.
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20 | a8083063 | Iustin Pop | |
21 | a8083063 | Iustin Pop | |
22 | a8083063 | Iustin Pop | """Module encapsulating ssh functionality.
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23 | a8083063 | Iustin Pop |
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24 | a8083063 | Iustin Pop | """
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25 | a8083063 | Iustin Pop | |
26 | a8083063 | Iustin Pop | |
27 | a8083063 | Iustin Pop | import os |
28 | a8083063 | Iustin Pop | |
29 | a8083063 | Iustin Pop | from ganeti import logger |
30 | a8083063 | Iustin Pop | from ganeti import utils |
31 | a8083063 | Iustin Pop | from ganeti import errors |
32 | 82122173 | Iustin Pop | from ganeti import constants |
33 | 1ff08570 | Michael Hanselmann | from ganeti import ssconf |
34 | 82122173 | Iustin Pop | |
35 | 82122173 | Iustin Pop | |
36 | 70d9e3d8 | Iustin Pop | def GetUserFiles(user, mkdir=False): |
37 | 70d9e3d8 | Iustin Pop | """Return the paths of a user's ssh files.
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38 | 70d9e3d8 | Iustin Pop |
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39 | 70d9e3d8 | Iustin Pop | The function will return a triplet (priv_key_path, pub_key_path,
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40 | 70d9e3d8 | Iustin Pop | auth_key_path) that are used for ssh authentication. Currently, the
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41 | 70d9e3d8 | Iustin Pop | keys used are DSA keys, so this function will return:
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42 | 70d9e3d8 | Iustin Pop | (~user/.ssh/id_dsa, ~user/.ssh/id_dsa.pub,
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43 | 70d9e3d8 | Iustin Pop | ~user/.ssh/authorized_keys).
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44 | 70d9e3d8 | Iustin Pop |
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45 | 70d9e3d8 | Iustin Pop | If the optional parameter mkdir is True, the ssh directory will be
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46 | 70d9e3d8 | Iustin Pop | created if it doesn't exist.
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47 | 70d9e3d8 | Iustin Pop |
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48 | 70d9e3d8 | Iustin Pop | Regardless of the mkdir parameters, the script will raise an error
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49 | 70d9e3d8 | Iustin Pop | if ~user/.ssh is not a directory.
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50 | 70d9e3d8 | Iustin Pop |
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51 | 70d9e3d8 | Iustin Pop | """
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52 | 70d9e3d8 | Iustin Pop | user_dir = utils.GetHomeDir(user) |
53 | 70d9e3d8 | Iustin Pop | if not user_dir: |
54 | 70d9e3d8 | Iustin Pop | raise errors.OpExecError("Cannot resolve home of user %s" % user) |
55 | 70d9e3d8 | Iustin Pop | |
56 | 70d9e3d8 | Iustin Pop | ssh_dir = os.path.join(user_dir, ".ssh")
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57 | 70d9e3d8 | Iustin Pop | if not os.path.lexists(ssh_dir): |
58 | 70d9e3d8 | Iustin Pop | if mkdir:
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59 | 70d9e3d8 | Iustin Pop | try:
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60 | 70d9e3d8 | Iustin Pop | os.mkdir(ssh_dir, 0700)
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61 | 70d9e3d8 | Iustin Pop | except EnvironmentError, err: |
62 | 70d9e3d8 | Iustin Pop | raise errors.OpExecError("Can't create .ssh dir for user %s: %s" % |
63 | 70d9e3d8 | Iustin Pop | (user, str(err)))
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64 | 70d9e3d8 | Iustin Pop | elif not os.path.isdir(ssh_dir): |
65 | 70d9e3d8 | Iustin Pop | raise errors.OpExecError("path ~%s/.ssh is not a directory" % user) |
66 | 70d9e3d8 | Iustin Pop | |
67 | 70d9e3d8 | Iustin Pop | return [os.path.join(ssh_dir, base)
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68 | 70d9e3d8 | Iustin Pop | for base in ["id_dsa", "id_dsa.pub", "authorized_keys"]] |
69 | 70d9e3d8 | Iustin Pop | |
70 | 70d9e3d8 | Iustin Pop | |
71 | c92b310a | Michael Hanselmann | class SshRunner: |
72 | c92b310a | Michael Hanselmann | """Wrapper for SSH commands.
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73 | a8083063 | Iustin Pop |
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74 | a8083063 | Iustin Pop | """
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75 | 1ff08570 | Michael Hanselmann | def __init__(self, sstore=None): |
76 | 1ff08570 | Michael Hanselmann | if sstore is None: |
77 | 1ff08570 | Michael Hanselmann | self.sstore = ssconf.SimpleStore()
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78 | 1ff08570 | Michael Hanselmann | else:
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79 | 1ff08570 | Michael Hanselmann | self.sstore = sstore
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80 | 1ff08570 | Michael Hanselmann | |
81 | 652d6694 | Michael Hanselmann | def _BuildSshOptions(self, batch, ask_key, use_cluster_key, |
82 | 652d6694 | Michael Hanselmann | strict_host_check): |
83 | f6d9f4c3 | Michael Hanselmann | options = [ |
84 | f6d9f4c3 | Michael Hanselmann | "-oEscapeChar=none",
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85 | f6d9f4c3 | Michael Hanselmann | "-oHashKnownHosts=no",
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86 | f6d9f4c3 | Michael Hanselmann | "-oGlobalKnownHostsFile=%s" % constants.SSH_KNOWN_HOSTS_FILE,
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87 | f6d9f4c3 | Michael Hanselmann | "-oUserKnownHostsFile=/dev/null",
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88 | f6d9f4c3 | Michael Hanselmann | ] |
89 | f6d9f4c3 | Michael Hanselmann | |
90 | f6d9f4c3 | Michael Hanselmann | if use_cluster_key:
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91 | f6d9f4c3 | Michael Hanselmann | options.append("-oHostKeyAlias=%s" % self.sstore.GetClusterName()) |
92 | f6d9f4c3 | Michael Hanselmann | |
93 | 652d6694 | Michael Hanselmann | # TODO: Too many boolean options, maybe convert them to more descriptive
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94 | 652d6694 | Michael Hanselmann | # constants.
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95 | 652d6694 | Michael Hanselmann | |
96 | f6d9f4c3 | Michael Hanselmann | # Note: ask_key conflicts with batch mode
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97 | f6d9f4c3 | Michael Hanselmann | if batch:
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98 | f6d9f4c3 | Michael Hanselmann | if ask_key:
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99 | f6d9f4c3 | Michael Hanselmann | raise errors.ProgrammerError("SSH call requested conflicting options") |
100 | f6d9f4c3 | Michael Hanselmann | |
101 | 652d6694 | Michael Hanselmann | options.append("-oBatchMode=yes")
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102 | 652d6694 | Michael Hanselmann | |
103 | 652d6694 | Michael Hanselmann | if strict_host_check:
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104 | 652d6694 | Michael Hanselmann | options.append("-oStrictHostKeyChecking=yes")
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105 | 652d6694 | Michael Hanselmann | else:
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106 | 652d6694 | Michael Hanselmann | options.append("-oStrictHostKeyChecking=no")
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107 | f6d9f4c3 | Michael Hanselmann | |
108 | f6d9f4c3 | Michael Hanselmann | elif ask_key:
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109 | f6d9f4c3 | Michael Hanselmann | options.extend([ |
110 | f6d9f4c3 | Michael Hanselmann | "-oStrictHostKeyChecking=ask",
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111 | f6d9f4c3 | Michael Hanselmann | ]) |
112 | f6d9f4c3 | Michael Hanselmann | |
113 | f6d9f4c3 | Michael Hanselmann | return options
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114 | 1ff08570 | Michael Hanselmann | |
115 | 8f07f831 | Michael Hanselmann | def BuildCmd(self, hostname, user, command, batch=True, ask_key=False, |
116 | 652d6694 | Michael Hanselmann | tty=False, use_cluster_key=True, strict_host_check=True): |
117 | c92b310a | Michael Hanselmann | """Build an ssh command to execute a command on a remote node.
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118 | c92b310a | Michael Hanselmann |
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119 | c92b310a | Michael Hanselmann | Args:
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120 | c92b310a | Michael Hanselmann | hostname: the target host, string
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121 | c92b310a | Michael Hanselmann | user: user to auth as
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122 | c92b310a | Michael Hanselmann | command: the command
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123 | c92b310a | Michael Hanselmann | batch: if true, ssh will run in batch mode with no prompting
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124 | c92b310a | Michael Hanselmann | ask_key: if true, ssh will run with StrictHostKeyChecking=ask, so that
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125 | c92b310a | Michael Hanselmann | we can connect to an unknown host (not valid in batch mode)
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126 | 51144e33 | Michael Hanselmann | use_cluster_key: Whether to expect and use the cluster-global SSH key
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127 | 652d6694 | Michael Hanselmann | strict_host_check: Whether to check the host's SSH key at all
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128 | c92b310a | Michael Hanselmann |
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129 | c92b310a | Michael Hanselmann | Returns:
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130 | c92b310a | Michael Hanselmann | The ssh call to run 'command' on the remote host.
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131 | c92b310a | Michael Hanselmann |
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132 | c92b310a | Michael Hanselmann | """
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133 | fff33d70 | Michael Hanselmann | argv = [constants.SSH, "-q"]
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134 | 652d6694 | Michael Hanselmann | argv.extend(self._BuildSshOptions(batch, ask_key, use_cluster_key,
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135 | 652d6694 | Michael Hanselmann | strict_host_check)) |
136 | 8f07f831 | Michael Hanselmann | if tty:
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137 | 8f07f831 | Michael Hanselmann | argv.append("-t")
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138 | c92b310a | Michael Hanselmann | argv.extend(["%s@%s" % (user, hostname), command])
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139 | c92b310a | Michael Hanselmann | return argv
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140 | c92b310a | Michael Hanselmann | |
141 | 54ab6aec | Michael Hanselmann | def Run(self, *args, **kwargs): |
142 | c92b310a | Michael Hanselmann | """Runs a command on a remote node.
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143 | c92b310a | Michael Hanselmann |
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144 | c92b310a | Michael Hanselmann | This method has the same return value as `utils.RunCmd()`, which it
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145 | c92b310a | Michael Hanselmann | uses to launch ssh.
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146 | c92b310a | Michael Hanselmann |
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147 | c92b310a | Michael Hanselmann | Args:
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148 | 54ab6aec | Michael Hanselmann | See SshRunner.BuildCmd.
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149 | c92b310a | Michael Hanselmann |
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150 | c92b310a | Michael Hanselmann | Returns:
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151 | c92b310a | Michael Hanselmann | `utils.RunResult` like `utils.RunCmd()`
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152 | c92b310a | Michael Hanselmann |
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153 | c92b310a | Michael Hanselmann | """
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154 | 54ab6aec | Michael Hanselmann | return utils.RunCmd(self.BuildCmd(*args, **kwargs)) |
155 | c92b310a | Michael Hanselmann | |
156 | c92b310a | Michael Hanselmann | def CopyFileToNode(self, node, filename): |
157 | c92b310a | Michael Hanselmann | """Copy a file to another node with scp.
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158 | c92b310a | Michael Hanselmann |
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159 | c92b310a | Michael Hanselmann | Args:
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160 | c92b310a | Michael Hanselmann | node: node in the cluster
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161 | c92b310a | Michael Hanselmann | filename: absolute pathname of a local file
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162 | c92b310a | Michael Hanselmann |
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163 | c92b310a | Michael Hanselmann | Returns:
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164 | c92b310a | Michael Hanselmann | success: True/False
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165 | a8083063 | Iustin Pop |
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166 | c92b310a | Michael Hanselmann | """
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167 | c92b310a | Michael Hanselmann | if not os.path.isabs(filename): |
168 | c92b310a | Michael Hanselmann | logger.Error("file %s must be an absolute path" % (filename))
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169 | c92b310a | Michael Hanselmann | return False |
170 | a8083063 | Iustin Pop | |
171 | 1d544ba3 | Michael Hanselmann | if not os.path.isfile(filename): |
172 | 1d544ba3 | Michael Hanselmann | logger.Error("file %s does not exist" % (filename))
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173 | 1d544ba3 | Michael Hanselmann | return False |
174 | 1d544ba3 | Michael Hanselmann | |
175 | fff33d70 | Michael Hanselmann | command = [constants.SCP, "-q", "-p"] |
176 | 652d6694 | Michael Hanselmann | command.extend(self._BuildSshOptions(True, False, True, True)) |
177 | c92b310a | Michael Hanselmann | command.append(filename) |
178 | c92b310a | Michael Hanselmann | command.append("%s:%s" % (node, filename))
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179 | a8083063 | Iustin Pop | |
180 | c92b310a | Michael Hanselmann | result = utils.RunCmd(command) |
181 | a8083063 | Iustin Pop | |
182 | c92b310a | Michael Hanselmann | if result.failed:
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183 | c92b310a | Michael Hanselmann | logger.Error("copy to node %s failed (%s) error %s,"
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184 | c92b310a | Michael Hanselmann | " command was %s" %
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185 | c92b310a | Michael Hanselmann | (node, result.fail_reason, result.output, result.cmd)) |
186 | a8083063 | Iustin Pop | |
187 | c92b310a | Michael Hanselmann | return not result.failed |
188 | a8083063 | Iustin Pop | |
189 | c92b310a | Michael Hanselmann | def VerifyNodeHostname(self, node): |
190 | c92b310a | Michael Hanselmann | """Verify hostname consistency via SSH.
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191 | a8083063 | Iustin Pop |
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192 | c92b310a | Michael Hanselmann | This functions connects via ssh to a node and compares the hostname
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193 | c92b310a | Michael Hanselmann | reported by the node to the name with have (the one that we
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194 | c92b310a | Michael Hanselmann | connected to).
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195 | a8083063 | Iustin Pop |
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196 | c92b310a | Michael Hanselmann | This is used to detect problems in ssh known_hosts files
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197 | c92b310a | Michael Hanselmann | (conflicting known hosts) and incosistencies between dns/hosts
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198 | c92b310a | Michael Hanselmann | entries and local machine names
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199 | a8083063 | Iustin Pop |
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200 | c92b310a | Michael Hanselmann | Args:
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201 | c92b310a | Michael Hanselmann | node: nodename of a host to check. can be short or full qualified hostname
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202 | a8083063 | Iustin Pop |
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203 | c92b310a | Michael Hanselmann | Returns:
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204 | c92b310a | Michael Hanselmann | (success, detail)
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205 | c92b310a | Michael Hanselmann | where
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206 | c92b310a | Michael Hanselmann | success: True/False
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207 | c92b310a | Michael Hanselmann | detail: String with details
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208 | a8083063 | Iustin Pop |
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209 | c92b310a | Michael Hanselmann | """
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210 | c92b310a | Michael Hanselmann | retval = self.Run(node, 'root', 'hostname') |
211 | a8083063 | Iustin Pop | |
212 | c92b310a | Michael Hanselmann | if retval.failed:
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213 | c92b310a | Michael Hanselmann | msg = "ssh problem"
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214 | c92b310a | Michael Hanselmann | output = retval.output |
215 | c92b310a | Michael Hanselmann | if output:
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216 | c92b310a | Michael Hanselmann | msg += ": %s" % output
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217 | c92b310a | Michael Hanselmann | return False, msg |
218 | a8083063 | Iustin Pop | |
219 | c92b310a | Michael Hanselmann | remotehostname = retval.stdout.strip() |
220 | a8083063 | Iustin Pop | |
221 | c92b310a | Michael Hanselmann | if not remotehostname or remotehostname != node: |
222 | c92b310a | Michael Hanselmann | return False, "hostname mismatch, got %s" % remotehostname |
223 | a8083063 | Iustin Pop | |
224 | c92b310a | Michael Hanselmann | return True, "host matches" |
225 | 75a5f456 | Michael Hanselmann | |
226 | 75a5f456 | Michael Hanselmann | |
227 | 75a5f456 | Michael Hanselmann | def WriteKnownHostsFile(cfg, sstore, file_name): |
228 | 75a5f456 | Michael Hanselmann | """Writes the cluster-wide equally known_hosts file.
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229 | 75a5f456 | Michael Hanselmann |
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230 | 75a5f456 | Michael Hanselmann | """
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231 | 75a5f456 | Michael Hanselmann | utils.WriteFile(file_name, mode=0700,
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232 | 75a5f456 | Michael Hanselmann | data="%s ssh-rsa %s\n" % (sstore.GetClusterName(),
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233 | 75a5f456 | Michael Hanselmann | cfg.GetHostKey())) |