Source Code for Module prompt.thread

  1  ############################################################################### 
  2  #                                                                             # 
  3  # Copyright (C) 2004-2005 Edward d'Auvergne                                   # 
  4  #                                                                             # 
  5  # This file is part of the program relax.                                     # 
  6  #                                                                             # 
  7  # relax is free software; you can redistribute it and/or modify               # 
  8  # it under the terms of the GNU General Public License as published by        # 
  9  # the Free Software Foundation; either version 2 of the License, or           # 
 10  # (at your option) any later version.                                         # 
 11  #                                                                             # 
 12  # relax is distributed in the hope that it will be useful,                    # 
 13  # but WITHOUT ANY WARRANTY; without even the implied warranty of              # 
 14  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               # 
 15  # GNU General Public License for more details.                                # 
 16  #                                                                             # 
 17  # You should have received a copy of the GNU General Public License           # 
 18  # along with relax; if not, write to the Free Software                        # 
 19  # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA   # 
 20  #                                                                             # 
 21  ############################################################################### 
 22   
 23  import sys 
 24   
 25  import help 
 26   
 27   
 28 -class Threading: 
 29 -    def __init__(self, relax): 
 30          # Help. 
 31          self.__relax_help__ = \ 
 32          """Class for controlling threading of calculations.""" 
 33   
 34          # Add the generic help string. 
 35          self.__relax_help__ = self.__relax_help__ + "\n" + help.relax_class_help 
 36   
 37          # Place relax in the class namespace. 
 38          self.__relax__ = relax 
 39   
 40   
 41 -    def read(self, file="hosts", dir="~/.relax"): 
 42          """Function for reading a file containing entries for each computer to run calculations on. 
 43   
 44          Keyword Arguments 
 45          ~~~~~~~~~~~~~~~~~ 
 46   
 47          file:  The name of the file containing the host entries. 
 48   
 49          dir:  The directory where the hosts file is located. 
 50   
 51   
 52          Description 
 53          ~~~~~~~~~~~ 
 54   
 55          Certain functions within relax are coded to handle threading.  This is achieved by running 
 56          multiple instances of relax on different processes or computers for each thread.  The 
 57          default behaviour is that the parent instance of relax will execute all the code, however if 
 58          a hosts file is read or a hosts entry manually entered, then the threaded code will run on 
 59          the specified hosts.  This function is for reading a hosts file which should contain an 
 60          an entry for each computer on which to run calculations. 
 61   
 62          For remote computers, a SSH connection will be attempted.  Public key authentication must be 
 63          enabled to run calculations on remote machines so that thread can be created without asking 
 64          for a password.  Details on how to do this are given below. 
 65   
 66   
 67          The format of the hosts file is as follows.  Default values are specified by placing the 
 68          character '-' in the corresponding column.  Columns can be separated by any whitespace 
 69          character, and all columns must contain an entry.  Any lines beginning with a hash will be 
 70          ignored. 
 71   
 72          Column 1:  The host name or IP address of the computer on which to run a thread. 
 73   
 74          Column 2:  The login name of the user on the remote machine.  The default is to use the same 
 75          name as the current user. 
 76   
 77          Column 3:  The full program path.  The default is to run 'relax'.  This only works if relax 
 78          can be found in the environmental variable $PATH, as alias are not recognised. 
 79   
 80          Column 4:  The working directory where thread specific files are stored.  The default is 
 81          '~/.relax' where the tilde '~' symbol represents the user's home directory on the remote 
 82          machine. 
 83   
 84          Column 5:  The priority value for running the program.  The default is 15.  The remote 
 85          instances of relax will be niced to this value. 
 86   
 87          Column 6:  The number of CPU or CPU cores on the machine.  The default is 1.  A thread is 
 88          started for each CPU. 
 89   
 90          An example is: 
 91   
 92          ------------------------------------------------------------------------------------------- 
 93          # Host          User name       Program path            Working directory    Priority  CPUs 
 94          localhost       -               -                       -                    0         2 
 95          192.168.0.10    dauvergne       /usr/local/bin/relax    -                    -         - 
 96          192.168.0.11    edward          -                       -                    -         - 
 97          ------------------------------------------------------------------------------------------- 
 98   
 99          In this case, two threads will be run on the parent computer which would be either a dual 
100          CPU system or a dual core 'Hyper threaded' Pentium processor.  These threads will have the 
101          highest level user priority of 0.  The other two machines will have single threads running 
102          with a low priority of 15. 
103   
104          Once threading is enabled, to allow calculations to run on the parent machine a 'localhost' 
105          entry should be included. 
106   
107   
108          If the keyword argument 'dir' is set to None, the hosts file will be assumed to be in the 
109          current working directory. 
110   
111   
112          SSH Public Key Authentication 
113          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
114   
115          To enable SSH Public Key Authentication for the use of ssh, sftp, and scp without having to 
116          type a password, use the following steps.  This is essential for running a thread on a 
117          remote machine. 
118   
119          If the files 'id_rsa' and 'id_rsa.pub' do not exist in the directory '~/.ssh', type: 
120   
121          $ ssh-keygen -t rsa 
122   
123          Press enter three times when asked for input.  This will generate the two identification 
124          files.  Then, to copy the public key into the 'authorized_keys' file on the remote machine, 
125          type: 
126   
127          $ ssh zucchini "echo $(cat ~/.ssh/id_rsa.pub) >> ~/.ssh/authorized_keys" 
128   
129          Make sure you replace 'zucchini' with the name or IP address of the remote machine.  To use 
130          DSA rather than RSA authentication, replace 'rsa' with 'dsa' in the above commands. 
131          Normally the sshd keyword StrictModes, which is found in the file '/etc/ssh/sshd_config', is 
132          set to 'yes' or, if unspecified, defaults to 'yes'.  In this case, public key authentication 
133          may fail as the permissions of the remote file '~/.ssh/authorized_keys' may be too 
134          permissive.  The file should only be read/write for the user, ie 600.  To remotely change 
135          the permissions, type: 
136   
137          $ ssh zucchini "chmod 600 ~/.ssh/authorized_keys" 
138   
139          One last keyword may need to be changed in the file '/etc/ssh/sshd_config'.  If the keyword 
140          PubkeyAuthentication is set to 'no', change this to 'yes'.  The default is yes, so if the 
141          keyword is missing or is commented out, nothing needs to be done. 
142   
143          Public key authentication should now work.  To test, type: 
144   
145          $ ssh zucchini 
146   
147          This should securely login into the remote machine without asking for a password.  If a 
148          password prompt appears, check all the permissions on the directory '~/.ssh' and all files 
149          within or set the sshd_config keyword StrictModes to 'no'. 
150   
151          $ ssh zucchini "chmod 700 ~/.ssh/" 
152          $ ssh zucchini "chmod 600 ~/.ssh/*" 
153          $ ssh zucchini "chmod 644 ~/.ssh/*.pub" 
154   
155          Finally, if all else fails, make sure the three lines 
156           
157          ----- 
158          RSAAuthentication yes 
159          PubkeyAuthentication yes 
160          AuthorizedKeysFile      .ssh/authorized_keys 
161          ----- 
162   
163          of the file 'sshd_config' found within the directory '/etc/ssh/' are uncommented and not set 
164          to 'no' or the 'AuthorizedKeysFile' set to another file name. 
165          """ 
166   
167          # Function intro text. 
168          if self.__relax__.interpreter.intro: 
169              text = sys.ps3 + "thread.read(" 
170              text = text + "file=" + `file` 
171              text = text + ", dir=" + `dir` + ")" 
172              print text 
173   
174          # The file name. 
175          if type(file) != str: 
176              raise RelaxStrError, ('file', file) 
177   
178          # Directory. 
179          if dir != None and type(dir) != str: 
180              raise RelaxNoneStrError, ('directory name', dir) 
181   
182          # Execute the functional code. 
183          self.__relax__.threading.read(file=file, dir=dir) 
184