Tuesday, February 04, 2014

Why I love bash - simple remote connections

Bash is my go-to language for busting out sysadmin stuff.  I've been ramping up with python for a while now, and for more complicated tasks, it's fantastic;  it should probably even be fantastic for simple tasks.  But, there is one thing that I do all of the time in Bash that I have yet to find a way to replicate without unnecessary complexity in python:

#!/bin/bash
agregateResults (); { while read line; do echo "Program Output: $line"; done; }
clientCode (); { echo "I am client $(hostname)."; }
if [[ "${1}" == "client" ]]; then
    clienCode
else
    for server in  ${*}; do
        cat ${0} | ssh ${server} -s client
    done | agregateResults
fi

This is so freaking useful.  I have servers across multiple domains and I need to run script to aggregate data from all of them, but I can't always count on network file systems being available, etc.  This lets me have a script in once place and execute the same code everywhere without fumbling with copying it ahead of time, etc.   It's so clean and easy.

When I try to find out how to do this with Python, I read all kinds of stuff about parallels, Paramiko, blah blah blah... it's all so complicated.  There has to be a five-liner example out there somewhere of how to do the same kind of thing.  

Started a code-golf at stackexchange for this one: http://codegolf.stackexchange.com/questions/20008/self-execute-over-ssh

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