How to use dsh and password-less ssh in-between the nodes

It's very easy to get password-less ssh working in-between the nodes, you just need a proper ssh-keypair in your home.

This script will take the necessary steps, but you can do it manually (see below):

#!/bin/sh

if [ -s $HOME/.ssh/authorized_keys ];then
        echo "You have already a ~/.ssh/authorized_keys"
        echo "call ssh-keygen manually and"
        echo "cat ~/.ssh/ide_rsa.pub >> ~/.ssh/authorized_keys"
        exit 0
fi
if [ -s $HOME/.ssh/id_rsa ];then
        echo "You have already a keypair"
        echo "rm ~/.ssh/id_rsa  ~/.ssh/id_rsa.pub"
        echo "try it again"
        echo "or /usr/bin/ssh-keygen -f \"another name\""
        exit 0
fi

/usr/bin/ssh-keygen -N '' -f $HOME/.ssh/id_rsa
cat $HOME/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys
mkdir -p /work/$USER/.ssh
cp $HOME/.ssh/authorized_keys /work/$USER/.ssh/.

Manual approach - if you are sure you don't already have a keypair or would lke to overwrite it:

/usr/bin/ssh-keygen -N '' -f $HOME/.ssh/id_rsa
cat $HOME/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys
mkdir -p /work/$USER/.ssh
cp $HOME/.ssh/authorized_keys /work/$USER/.ssh/.

When this works (i.e. ssh a0304 should work without asking for a password) you can also start using dsh, e.g. try running dsh -aMF25 uptime and this should loop over all nodes running the uptime command there.