Re: Updating files in /etc Remotely (and automated)
On Sep 12, 2010, at 12:37 PM, Rob Owens wrote:
> On Sun, Sep 12, 2010 at 12:01:26PM -0400, Hal Vaughan wrote:
>> On Sep 12, 2010, at 10:51 AM, Rob Owens wrote:
>>> On Sat, Sep 11, 2010 at 05:15:50PM -0400, Hal Vaughan wrote:
>>>> I will be working with a server on the Internet that uses rsync and is running Debian. I will be setting up initial /etc/rsyncd.conf and /etc/rsyncd.secrets files on it. But along the way, whenever a new user is added, they'll need to be updated. I can use ssh on this system, but, of course, I don't want to allow root access.
>>>> I'd like to be able to have these files updated automatically when I add a new user to another system. I could create new copies of the files locally, where the users are added and use scp to copy them to a directory on the server. But that's where there are problems. How can I chown the files to root, copy them to /etc, and chmod as needed for rsync to use them automatically?
>>>> I don't see a way to do that without security issues. I need to somehow ssh in and do an su or run three commands as sudo (I need to mv the file, chown it, and chmod it).
>>>> I am far from an expert in security, but I can see that if I have anything in place to make this easy, then anyone hacking my user account could easily mess up anything in the system.
>>>> Is there some way I can set this up so I can update rsyncd.conf and rsyncd.secrets only automatically when I have the newer versions on my local system to be uploaded?
>>> When using ssh keys to log in, you can specify (in
>>> ~/.ssh/authorized_keys) a command which will automatically run when that
>>> key is used to log in. And that key will be useless to do anything
>>> else. Simply using that key to conenct to the remote server will run
>>> that command.
>>> The authorized_keys file would look something like this:
>>> command="/path/to/my/script" ssh-rsa AAAAB3NzaC1yc2EAAA.... me@myhost
>> I see. That would make perfect sense and I see I can use -i to specify which key to use, so for normal situations, I just use "ssh host," and when I want this done, I do "ssh -i .ssh/special_key host" instead.
>> I thought I knew about authorized keys, but didn't know you could specify a command to be run in that file.
>>> You could use this to ssh into the remote server as root, or as a user
>>> with very specify sudo privileges that will allow your script to run.
>>> (The script would perform the file changes you need done, or simply
>>> rsync them from your local machine).
>> But if I'm not running as root, from what I can see, no matter what I do with sudo, I still have to type in a password, don't I? using the authorized_keys file and specifying what can be done at login does a lot to help with security, but if I don't log in as root, no matter what I do, I'll still have to type in a password to use either "su" or "sudo," right? Or is there a way around it? I was going through man pages, but it seems both require a password to be typed in no matter what.
> In /etc/sudoers, you can specify "NOPASSWD", like this:
> someuser ALL=NOPASSWD: /path/to/some/command
> Then "someuser" can run the specified command as root without typing a
My bad, in this case. I read the SUDO man page over a few times, but forgot to read SUDOERS man page. Thanks!