Permission error while trying to add a content to a remote host's file

Question

I have a script that should create a file and add content to a file on the hosts listed in a file:

#!/bin/bash

while read f; do

   sshpass -p "mypassword" ssh-copy-id myusername@"$f"
   ssh -ntt myusername@"$f" '
        echo mypassword | sudo -S touch  /etc/sudoers.d/10_icinga_check_postfix_queue || true
        echo mypassword | sudo -S echo "icinga ALL=(ALL) NOPASSWD: /usr/lib64/nagios/plugins/check_postfix_queue" > /etc/sudoers.d/10_icinga_check_postfix_queue || true' </dev/null

done < linux-list.txt

But I get an error and not sure why. can you please help?

bash: line 1: /etc/sudoers.d/10_icinga_check_postfix_queue: Permission denied

Thanks

Answer 1

How about this refactoring of Gordon's answer? There's no need to separately touch the file you are about to overwrite anyway.

#!/bin/bash

while read -r f; do
   sshpass -p "mypassword" ssh-copy-id myusername@"$f"
   ssh -ntt myusername@"$f" '
        echo mypassword | sudo -S bash -c "echo \"icinga ALL=(ALL) NOPASSWD: /usr/lib64/nagios/plugins/check_postfix_queue, /usr/lib64/nagios/plugins/contrib/restart_service.sh\" > /etc/sudoers.d/10_icinga_check_postfix_queue" || true' </dev/null    
done < linux-list.txt

Notice also the (re-) introduction of the -r option to read. It's probably not crucial here, but getting used to it can help avoid unpleasant surprises where it does make a difference.

Answer 2

Try this:

#!/bin/bash

while read f; do

   sshpass -p "mypassword" ssh-copy-id myusername@"$f"
   ssh -ntt myusername@"$f" '
        echo mypassword | sudo -S touch  /etc/sudoers.d/10_icinga_check_postfix_queue || true
        echo mypassword | sudo -S bash -c "echo \"icinga ALL=(ALL) NOPASSWD: /usr/lib64/nagios/plugins/check_postfix_queue, /usr/lib64/nagios/plugins/contrib/restart_service.sh\" > /etc/sudoers.d/10_icinga_check_postfix_queue" || true' </dev/null

done < linux-list.txt

This will run the entire echo ... >file command in a sudo shell (rather than just running echo with sudo, and the >file part unprivileged). The tricky thing here is the quoting: there's a single-quoted string that's being passed to ssh as an argument (the commands to run on the remote computer); inside that, there's a double-quoted string being passed to bash -c as the command run (as root), and inside that, there's another quoted string. Since quotes don't nest, the innermost quoted string uses escaped double-quotes (\"), which get passed unchanged when the single-quoted string is parsed on the local computer, then when the outer double-quoted string gets parsed by the remote shell the escapes get removed, so by the time the remote root shell sees it, it's a normal double-quoted string. Yes, this is a mess, but it should work (though I haven't tested it).