gsh – Run linux commands on many other linux server at once



gsh – Run linux commands on many other linux server at once

Group Shell (also called gsh) is a remote shell multiplexor. It lets you control many remote shells at once in a single shell. Unlike other commands dispatchers, it is interactive, so shells spawned on the remote hosts are persistent.

GSH is a pluggable version of DSH (Distributed Shell) written in Python. Both a module and a command-line tool for running a shell command over multiple machines are included. GSH can be extended by adding new host loaders as well as hooking into various stages of the runtime.

It requires only a SSH server on the remote hosts, or some other way to open a remote shell.
gsh allows you to run commands on multiple hosts by adding tags to the gsh command.

e.g > gsh tag “remote command”

Important things to remember:
/etc/ghosts contains a list of all the servers and tags. gsh is a lot more fun once you’ve set up ssh keys to your servers

SYSTEMS is a combination of ghost macros. See ghosts(1).

CMD is the command to run
-h, –help Display full help
-d, –debug Turn on exeuction debugging reports
-h, –no-host-prefix Does not prefix output lines with the host name
-s, –show-commands Displays the command before the output report
-n, –open-stdin Leaves stdin open when running (scary!)
-l, –user USER SSH’s to the host as user USER
-r, –run-locally Run commands locally (replaces $host with host)
-o, –self-remote Run locally instead of over SSH for local host
-V, –version Report the version and exit

You set up a /etc/ghosts file containing your servers in groups such as web, db, RHEL4, x86_64, or whatever (man ghosts) then you use that group when you call gsh.

How to run the gsh?
> gsh linux “cat /etc/redhat-release; uname -r”

You can also combine or split ghost groups, using cpanel+vps or web-RHEL4, for example.

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