oarsh - Online in the Cloud

This is the command oarsh that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator

PROGRAM:

NAME


oarsh - remote shell connector for OAR batch scheduler.

oarcp - oarsh compagnon to copy files from a node or to a node.

SYNOPSIS


oarsh [OPTIONS] <NODENAME> [COMMAND]

oarcp [OPTIONS] [NODENAME:]<PATHNAME> [NODENAME:]<PATHNAME>

DESCRIPTION


Connect a node from the submission frontal of the cluster or any node.

OPTIONS


oarsh uses OpenSSH client (the ssh command) underneath to perform the connection. Thus any
OpenSSH option can be used.

ENVIRONMENT


OAR_JOB_ID
From the frontal of the cluster or any node, specify the Id of the job oarsh must
connect to.

OAR_JOB_KEY_FILE
Specify a job key oarsh must use, e.g. the one that was used for the submission of the
job you want to connect to. This is mandatory when connecting to a node of a job from
a host that does not belong to the nodes managed by the OAR server the job was
submitted to. The -i option may be used as well.

CONFIGURATION


In order to provide the user with the ability to use oarsh to connect both the nodes of
his job or other hosts that live out of the scope of his job, oarsh tries to read two
configuration files: first ~/.oarsh-host-include then ~/.oarsh-hosts-exclude.

If exist, those files must contain one regular expression matching a hostname per line.

At execution time, if oarsh finds in ~/.oarsh-host-include a match for the hostname used
in the command line, it continues with the execution of oarsh, skipping
~/.oarsh-hosts-exclude file. If not, it tries to find a match in ~/.oarsh-hosts-exclude
and if one is found, then executes ssh with the same command line. Finally, it no match is
found (or for instance, if none of those files exists), it continues with the execution of
oarsh.

For instance, if all nodes look like name-XXX.domain, one may place ^[^\.]+-[[:digit:]]+
in ~/.oarsh-host-include and .* in ~/.oarsh-hosts-exclude and then can use oarsh to
connect any host.

The feature finally becomes really sexy when one considers placing a symlink to oarsh
named ssh, and then can always use the ssh command to connect any host.

EXAMPLES


Connecting from within our job, from one node to another one (node23):
> oarsh node-23

Connecting to a node (node23) of our job (Id: 4242) from the frontal of the cluster:
> OAR_JOB_ID=4242 oarsh node-23

Connecting to a node (node23) of our job that was submitted using a job key:
> OAR_JOB_KEY_FILE=~/my_key oarsh node-23

Same thing but using OpenSSH-like -i option:
> oarsh -i ~/my_key node-23

NOTES


All OpenSSH features should be inherited by oarsh, for instance X11 forwarding. However,
one feature that oarsh does break is the SSH Agent.

None of OpenSSH user configuration files (within ~/.ssh directory) are used by oarsh.

Use oarsh online using onworks.net services



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