I only just started on rewriting some ancient perl, ruby, and shell in Go for a practice project to pick up the basics of the language & libraries. This probably isn't terribly useful yet.

Original is here: https://github.com/tobert/perl-ssh-tools

gdsh is a set of tools for managing clusters over ssh. It's a couple generations removed from "dsh" and is written Go this time around. You are free to substitute whatever you want for the acronym, but the politically correct expansion is "Go Distributed SHell".

Cluster node lists are simple text files with one hostname or IP per line. Each node may optionally have a comment after a hash mark. The comment is used in places where it's sensible to show it, otherwise it's ignored. The SSH port may be specified with host:port format, otherwise the default of 22 is used.

Example: ~/.gdsh/nodes.default

node1.mydomain.com
node2.mydomain.com:22
node3.mydomain.com:22 # us-east-1a
node4.mydomain.com
127.0.0.1 # home sweet home

You might generate a list for a 1000 node Hadoop cluster:

for i in $(seq 1 1000)
do
    echo "hadoop-c1n${i}.mydomain.com" >> ~/.gdsh/nodes.hadoop
done
# run a command on all of them at once
gdsh run --list hadoop -c uptime

gdsh builds as a single multi-call binary. It can be executed as "gdsh [subcommand] [args]" or via links/symlinks to the binary such as "ln -s gdsh ~/bin/nssh" in which case it will automatically select the subcommand.

This is a simple ssh command wrapper that parses the arguments just enough to grab the hostname and set your screen title with escape codes. It's really handy if you use a lot of screens and ctrl-a " to list them. Patches to support tmux or xterm titles are welcome.

Run the given command or script on all the remote servers. Commands (-c) will be run from a shell wrapper that is pushed first. Scripts (-s) are run unmodified.

gdsh run --list default -c "sudo systemctl restart sshd.service"

Push a file to all servers in the list.

gdsh push --list default -L /etc/sysctl.conf -R /tmp/sysctl.conf
gdsh run --list default -c "sudo cp /tmp/sysctl.conf /etc/sysctl.conf"

Gets files from remote servers and stashes them locally, creating a directory per remote server.

gdsh pull --list default -L /tmp -R /etc/resolv.conf
ls -l /tmp/*/resolv.conf

serial mode

rsync (or similar), ping, local, psgrep, pkill

More advanced, probably much later:

netstat, sysstat

Add a few aliases to your local host in /etc/hosts then use those names in your gdsh lists.

In /etc/hosts:

# keep a backup, you can mess things up badly if this file breaks
127.0.0.1 localhost.localdomain	localhost h1 h2 h3
::1 localhost.localdomain	localhost h1 h2 h3

In ~/.gdsh/nodes.default:

localhost
h1
h2
h3

Then try it:

go build && ./gdsh run -c uptime

Copyright 2013 Albert P Tobey. All rights reserved. Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.