Run rsync with root permission on remote machine

Question

I want to sync a folder from my machine with a folder on a remote machine. The remote folder can only be manipulated by root. I have an account on the remote machine which can use sudo. How can I run rsync such that it has root permissions on the remote machine?

I've tried the following:

rsync -avz -e ssh /home/ubuntu/my/lovely/folder ubuntu@x.x.x.x:/remote/lovely/folder --delete --rsync-path="sudo rsync"

But (after entering my password) I get the following error:

sudo: no tty present and no askpass program specified

Answer 1

This is the solution I came up with:

rsync -R -avz -e ssh --rsync-path="echo mypassword | sudo -S  mkdir -p /remote/lovely/folder && sudo rsync" /home/ubuntu/my/lovely/folder ubuntu@x.x.x.x:/remote/lovely/folder --delete

Bit of a mission!

Answer 2

The solution on this blog worked really well for me: http://www.pplux.com/2009/02/07/rsync-root-and-sudo/.

Basically:

stty -echo; ssh myUser@REMOTE_SERVER "sudo -v"; stty echo  
rsync -avze ssh --rsync-path='sudo rsync' myUser@REMOTE_SERVER:/REMOTE_PATH/ LOCAL_PATH 

The first line allows for interactive password entry, without showing the password on the screen. Works great for me on Ubuntu 9.04.

Answer 3

Try this solution. In your sudoers file (/etc/sudoers) setup your user like this:

username ALL= NOPASSWD:/usr/bin/rsync

the NOPASSWD:/usr/bin/rsync tells sudo that when your user runs /usr/bin/rsync or just rsync that no password is needed.

Then your original --rsync-path="sudo rsync" should work.

Answer 4

You need a method to supply the password to sudo. An askpass program is designed to ask for passwords when the normal mechanisms aren't available. Setting up sudo to not require a password to run rsync as your userid is one option.

I normally configure key based login with appropriate restrictions for cases like this. If you configure a restricted key that an only run rsync as root then this kind of thing gets easier to do. Another alternative is to use an rsycnd process to handle the remote requests. The configuration provides a variety of restrictions that can be applied.

EDIT: I included a script to setup keys for key based loings in the Creating Userids on Clients section of my post on Setting up BackupPC on Linux. See also the documenation for ssh_config which details some of the things you can do with resticting key usage as shown in the script.

Answer 5

I'm amazed by the complexity of the existing answers. It's far easier and convenient to configure your systems (your PC and the remote host) so that you can connect as root to the remote host without using a password. And unlike the looks of it it's secure too.

1. On the remote host make sure that /etc/ssh/sshd_config has this line "PermitRootLogin without-password" (in many distributions it's there by default). This allows root to get an ssh shell using any authentication method except the insecure password prompt.
2. (If you don't already know how) follow any of the many tutorials on how to obtain passwordless login via ssh
3. Use rsync as you would normally do and without any password prompts.

Just don't forget that as long as the line in /root/.ssh/authorized_keys of the remote host is there that machine accepts root commands from your PC.

Answer 6

on remote machine

sudo apt install ssh-askpass
which ssh-askpass

then on local machine

rsync -av -e 'ssh -X' --rsync-path='SUDO_ASKPASS=/usr/libexec/openssh/ssh-askpass sudo -A rsync' /some/local/path user@remote:/some/remote/path

substitute path to ssh-askpass with actual path on remote machine

source: http://unix.bris.ac.uk/2015/08/04/rsync-between-two-hosts-using-sudo-and-a-password-prompt/

Answer 7

Here is what worked for me, considering that I want to keep password authentication (so I don't want to use NOPASSWD or keys) - on Ubuntu 14.04:

• "Open up" sudo on remote machine by disabling tty_tickets through a temporary file in /etc/sudoers.d/ (which should be supported on Debian, see /etc/sudoers.d/README), and "Update the user's cached credentials", which "extends the sudo timeout for another 15 minutes"
• Run the rsync with sudo as shown in other answers
• "Close down" sudo on remote machine by removing the temporary file in /etc/sudoers.d/, which re-enables tty_tickets

... or, with command lines:

ssh -t $REMOTEPC 'echo "Defaults !tty_tickets" | sudo tee /etc/sudoers.d/temp; sudo -v'
rsync -aP -e 'ssh' '--rsync-path=sudo rsync' /etc/pulse/client.conf $REMOTEPC:/etc/pulse/client-copy.conf
ssh -t $REMOTEPC 'sudo rm -v /etc/sudoers.d/temp; sudo -v'

These are the responses I get when running these commands on the local machine:

$ ssh -t $REMOTEPC 'echo "Defaults !tty_tickets" | sudo tee /etc/sudoers.d/temp; sudo -v'
remoteuser@$REMOTEPC's password: 
[sudo] password for remoteuser: 
Defaults !tty_tickets
Connection to $REMOTEPC closed.

$ rsync -aP -e 'ssh' '--rsync-path=sudo rsync' /etc/pulse/client.conf $REMOTEPC:/etc/pulse/client-copy.conf
remoteuser@$REMOTEPC's password: 
sending incremental file list
client.conf
           1269 100%    0.00kB/s    0:00:00 (xfr#1, to-chk=0/1)

$ ssh -t $REMOTEPC 'sudo rm -v /etc/sudoers.d/temp; sudo -v'
remoteuser@$REMOTEPC's password: 
removed ‘/etc/sudoers.d/temp’
[sudo] password for remoteuser: 
Connection to $REMOTEPC closed.

Note that sudo -v should be ran after each time files in /etc/sudoers.d/, so the changes therein are accepted.

Answer 8

Another method is to get around the permissions restrictions by initiating rsync on the remote machine. Instead of:

rsync /home/ubuntu/my/lovely/folder ubuntu@x.x.x.x:/remote/lovely/folder

You can do:

ssh ubuntu@x.x.x.x 'rsync ubuntu@y.y.y.y:/home/ubuntu/my/lovely/folder /remote/lovely/folder'

Where y.y.y.y is your local machine's IP address. This only works if your local machine can act as an SSH server.