passwordless rsync?

[Cameron Simpson]

On 29May2015 01:40, suvayu ali <fatkasuvayu+linux at gmail.com> wrote:
>I think the magic incantation for me was command="somecommand" is
>actually the whole command, with all the arguments.  From the man page,
>this wasn't clear to me.  I was trying to setup passwordless root login
>with PermitRootLogin set to forced-commands-only for backups with
>rsnapshot.
>
>Btw, to allow multiple commands from the same host, I guess I should
>have multiple lines for the same public key?  Also, any ideas what
>should be the command to allow rsnapshot backups?  I guess I need to
>figure out what are the arguments passed onto rsync by rsnapshot, and in
>which order.

Might I also suggest you consider reading "man rsync", specificly the section 
"USING RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION". In fact, the whole 
section starting at "CONNECTING TO AN RSYNC DAEMON"?

This details invoking rsync in daemon mode, which lets you use an rsyncd.conf 
file to control what is available (see "man rsyncd.conf").

Then you just put a suitable "rsync daemon mode with specified (or default) 
rsyncd.conf file" in the command="..." part of your authorized_keys file.

This may be a far more controllable and flexible way to give rsync access, 
because you can use the .conf file at the server end to decide what may be 
backed up, and the rsync command in all its glory at the client end to decide 
what to ask for in a given run.

Cheers,
Cameron Simpson <cs at zip.com.au>