Question

I had setup my clients & server for passwordless login. Like passwordless login by copying RSA key of server to all client’s /root/.ssh/id-rsa.pub. but this, I have done manually. I like to automate this process using shell script and providing password to the machines through script. If this problem is solved then I also want to use rsync to automate push items to all servers. Can any body help me in this regard.

Thank you

Answer 1

This script comes in Debian (and derivatives) machines, to distribute the keys. It’s called ssh-copy-id. You’d use it like this:

ssh-copy-id [-i identity_file] [user@]machine 

Then you’d enter the password and the copying would be done. You would do this one time only and then could use the rsync over ssh as usual.

#!/bin/sh  # Shell script to install your identity.pub on a remote machine # Takes the remote machine name as an argument. # Obviously, the remote machine must accept password authentication, # or one of the other keys in your ssh-agent, for this to work.  ID_FILE='${HOME}/.ssh/identity.pub'  if [ '-i' = '$1' ]; then   shift   # check if we have 2 parameters left, if so the first is the new ID file   if [ -n '$2' ]; then     if expr '$1' : '.*\.pub' ; then       ID_FILE='$1'     else       ID_FILE='$1.pub'     fi     shift         # and this should leave $1 as the target name   fi else   if [ x$SSH_AUTH_SOCK != x ] ; then     GET_ID='$GET_ID ssh-add -L'   fi fi  if [ -z '`eval $GET_ID`' ] && [ -r '${ID_FILE}' ] ; then   GET_ID='cat ${ID_FILE}' fi  if [ -z '`eval $GET_ID`' ]; then   echo '$0: ERROR: No identities found' >&2   exit 1 fi  if [ '$#' -lt 1 ] || [ '$1' = '-h' ] || [ '$1' = '--help' ]; then   echo 'Usage: $0 [-i [identity_file]] [user@]machine' >&2   exit 1 fi  { eval '$GET_ID' ; } | ssh $1 'umask 077; test -d .ssh || mkdir .ssh ; cat >> .ssh/authorized_keys' || exit 1  cat <<EOF Now try logging into the machine, with 'ssh '$1'', and check in:    .ssh/authorized_keys  to make sure we haven't added extra keys that you weren't expecting.  EOF