sshcmd                  package:nws                  R Documentation

_S_l_e_i_g_h _A_u_x_i_l_i_a_r_y _F_u_n_c_t_i_o_n

_D_e_s_c_r_i_p_t_i_o_n:

     This function is used by the sleigh constructor when starting
     workers on remote nodes using the 'ssh' command.  Note that it
     doesn't actually start any workers directly: it simply returns the
     program name and arguments to start a worker on the specified
     node.

_U_s_a_g_e:

     sshcmd(host, options)
     sshforwardcmd(host, options)

_A_r_g_u_m_e_n_t_s:

    host: Name of the worker machine to be started.

 options: An environment or list that contains information used to
          construct the command.  See 'defaultSleighOptions' for more
          information.

_D_e_t_a_i_l_s:

     'sshcmd' currently uses the following options: 'user', 
     'wrapperDir', 'workerWrapper', and 'python'.  The  'user' option
     is the most useful.

     'sshforward' works like 'sshcmd', but it makes use of the  'ssh
     -R' argument to tunnel the NWS server connection back to the
     master machine.  It uses the options 'nwsHostRemote' and
     'nwsPortRemote' to determine what bind address and port should be
     forwarded back to the master machine.

     Note that when using 'sshforwardcmd', you must specify a different
     value of 'nwsHostRemote', usually ''localhost''.

_V_a_l_u_e:

     A character vector, whose first element is the command that will
     be executed to start the worker, and whose subsequent elements are
     the arguments to the command.

_N_o_t_e:

     'sshcmd' and 'sshforwardcmd' are not intended to be  called
     directly by the user. They are called by the sleigh constructor
     when specified via the 'launch' argument.  You may want to execute
     it when debugging your sleigh option settings, but that can also
     be accomplished by setting the 'verbose' argument to 'TRUE'.

_S_e_e _A_l_s_o:

     'sleigh', 'defaultSleighOptions'

_E_x_a_m_p_l_e_s:

     ## Not run: 
     # Create a sleigh with workers on nodes n1 and n2 started via ssh:
     s <- sleigh(launch=sshcmd, nodeList=c('n1', 'n2'))

     # Same as previous, but as user 'frank':
     s <- sleigh(launch=sshcmd, nodeList=c('n1', 'n2'), user='frank')

     # Create two tunnels from workers n1 and n2 back the nws server
     # on the local machine:
     s <- sleigh(launch=sshforwardcmd, nodeList=c('n1', 'n2'),
                 nwsHostRemote='localhost')

     # Same as the previous example, but use port 9876 in case either
     # worker machine already has an nws server bound to port 8765:
     s <- sleigh(launch=sshforwardcmd, nodeList=c('n1', 'n2'),
                 nwsHostRemote='localhost', nwsPortRemote=9876)
     ## End(Not run)

