dyssh

A simple interface for issuing commands to multiple remote servers over SSH.

Usage

There are several command-line options, and dyssh supports interactive and non- interactive modes (although for scripting you should definitely be using the very exellent fabric module).

Basic usage looks something like this:

$ dyssh [OPTIONS] [COMMAND]

Omitting COMMAND and/or specifying --interactive will drop you into an interactive prompt. From there you can add/remove hosts and execute commands, check the output of those commands, and, if necessary, connect to an individual host interactively. This is especially useful for resolving issues/hung processes.

At the interactive prompt, :help will show avaialabe dyssh commands. Anything not prefixed by a : will be sent to the remote hosts.

At the system command line, --help will show you available options and flags.

Limitations and known issues

This is an early, still-experimental program (although I personally use it when working with remote hosts in a production environment, so I am fairly sure that it is free of any dangerous bugs).

It's worth pointing out that there are a million tools out there that do this very thing, most of which are more mature as pieces of software.

The main goal of this program is to provide a simple interface for simple operations, and was partly writting to satisfy my interest in the paramiko module.

That said, here are the most important caveats:

• Each command is run in a new pseudo-terminal session, so environmental variables have to be re-set on each command execution. In an interactive session this is taken care of transparently using the :env command. At the command line, you can use the --envvars flag.
• I have no idea how this program will handle extremely large amounts of output. Probably by eating all of your memory and then failing. Brief tests with yes were uh ... problematic. (Lots of time waiting for the program to finish reading all the output from the pty, CRTL-C doing nothing to save you, that sort of thing.) This is something that I hope to devise a better approach to in future.

Dependencies

• Python 2.7
• The paramiko Python module. Paramiko is available in the Python Package Index (using pip or easy_install) as well as in many Linux repositories (in Arch as python2-paramiko and Debian as python-paramiko).
• This program uses the termios module and makes a number of other POSIX assumptions, and so will not run on Windows without some modification. That said, I would welcome contributions in that regard.
• By default, I'm assuming you have the less pager installed on your system. If you don't, you can change it, either by using the config file mechanism, setting a --pager=<somepager> option, or editing config.py directly.

This has been tested on OS X, Debian, and Arch.