rsync – what? how? why?

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Hic, điên đầu. Sao ko tìm ra trang này sớm hơn, google index tệ quá :-j

source: http://transamrit.net/docs/rsync/

This document is meant to very quickly show how one can get a basic rsync server set up in Linux. For further information on rsync, see the documentation page or contact me. I’d appreciate any feedback you leave me, so I know whether this doc is helpful, and how to improve it in the future.

  1. Get rsync. If your distro doesn’t have packages, hit FreshMeat.
  2. Create a file: “/etc/rsyncd.conf“, with the contents: 
      max connections = 2
  log file = /var/log/rsync.log
  timeout = 300

  [pub]
  	comment = Random things available for download
  	path = /path/to/my/public/share
  	read only = yes
  	list = yes
  	uid = nobody
  	gid = nobody
  	auth users = pub
  	secrets file = /etc/rsyncd.secrets

    This will create a module named “pub” that points to “/path/to/my/public/share”, is read-only, allows access only to rsync user “pub”, and verifies the password from “/etc/rsyncd.secrets”. Note that this runs the rsync process as user and group “nobody”, so you may want to make the the files world readable (chmod a+r), and the directories world listable (chmod a+x). Also, if a user connects to your rsync without any files/dirs specified, this share will be listed.

    Note: On Debian, group “nobody” doesn’t exist. Use “nogroup” instead (same thing, different name) for the “gid” line. The same may be true for your distro if you get “invalid gid” errors when testing rsync.

    Optional: Some have asked how to control access to rsync by IP address or hostname. To accomplish this, you can use either of the “hosts allow” or “hosts deny” directives. The line(s) should go in the block following the module name (in this case, somewhere after “[pub]”), and take the format:

    hosts allow = 192.168.0.0/24

    This line would allow access from all hosts in the 192.168.0.x IP range, assuming they are properly authenticated by user/password, and block everyone else (“hosts deny” is not even necessary in this case, it’s implicit that all other hosts are denied). The IP/hostname specifications can take multiple forms, which are described in more detail in “man rsyncd.conf”.

    Optional: If you’re creating multiple rsync modules, you may be pleased to know that any of the parameters from the module section above can be moved to the global section. For example, if the “uid” and “gid” parameters from the “pub” section are moved into the global section above, those two settings will apply to “pub” and any other rsync module that doesn’t explicitly override the parameters.

  3. Create a file: “/etc/rsyncd.secrets“, with the contents: 
      pub:pub

    This simply makes a user pub, with password pub. Note that since this password is in plain text, the file MUST be owned by only root, and readable by only root (chmod 600 /etc/rsyncd.secrets). Otherwise, any local user/exploit may view the password, and rsync may not even start if the permissions are not correct.

  4. This step differs depending on which Linux distribution you use. For distributions that use the inetd “super-server” (such as Slackware), use the first subsection below. For those that use xinetd instead (such as Fedora), use the second subsection.
    1. Add to your: “/etc/inetd.conf“: 
        rsync	stream	tcp	nowait	root	/usr/bin/rsync	rsync --daemon

      Of course, you’ll want to change the path to whatever is correct on your system, though /usr/bin/rsync should be the case for most.

    2. Many distros that use xinetd already include a “/etc/xinetd.d/rsync” file. If this is the case, you can simply edit the file and change: 
        disable = yes

      to:

        disable = no

      If the file does not exist, create it, with the contents:

        service rsync
  {
  	disable         = no
  	socket_type     = stream
  	wait            = no
  	user            = root
  	server          = /usr/bin/rsync
  	server_args     = --daemon
  	log_on_failure  += USERID
  }
  5. Add to your: “/etc/services“: 
     rsync	873/tcp

    If your services file already lists the rsync port, you don’t need to add this entry (duh). Also, you can change 873 to any other number if you want to run rsync on a non-standard port.

  6. Run “killall -HUP inetd” (or “killall -HUP xinetd“, if applicable) as root, to restart the inetd/xinetd daemons. You can alternatively run “/etc/init.d/xinetd restart” if you prefer to restart xinetd that way. rsync should now be ready to listen on the specified port.


How to test your rsync setup:

  1. Run: “rsync rsync://pub@your-ip-or-hostname/“. After entering your password (also pub), rsync should list the only available share, pub.
  2. Run: “rsync rsync://pub@your-ip-or-hostname/pub/“. After entering your password, rsync should now give a file listing. If there are no files listed, place some files and directories in the directory and try again.
  3. Run: “rsync -v --progress --partial rsync://pub@your-ip-or-hostname/pub/someFile .” (you can abbreviate –partial –progress as -P). Your file should now be downloading.
  4. Run: “rsync -aPv rsync://pub@your-ip-or-hostname/pub/someDirectory .“. Your directory should now be downloading.

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