Subject: Re: Synchronizing Amanda with Applications 

>I looked at the archives.  I found some references to such wrappers,
>but I've failed to find a good example of one, and what needs to be done
>on which machine (client/server).

OK, you asked for it :-).

Some notes on the following over-engineered, under-tested, script:

  * It has **NOT** been run in a full Amanda setup, other than what
    little I did to make sure syntax was right and the general flow
    worked.

  * The script uses **EXAMPLE** execution point functions (see the code).
    You **WILL** have to change it to do what you want (and remove what
    you don't).

  * There are definitions of the Amanda debug directory (e.g. /tmp/amanda)
    and path to GNU tar (on the client) in the first few lines that may
    need to be tweaked for your environment.

  * It is written in ksh (although now that I think about it, I probably
    could have used Perl).  Hopefully the examples and your own shell
    coding experience will be sufficient to fit in what you need, but
    if you want some help, ask me offline.

The idea is to install this on the client and build Amanda there
using --with-gnutar=<path-to-script>.  Then set up the disks you want
to use this wrapper with GNU tar as the dump program in disklist and
add execution point functions (see the code) to the script to do what
you need.

Note that the script doesn't have to actually use GNU tar -- that's just
the trick to get Amanda to call it with a set of arguments that are easy
to decipher.  You can use a run_* function to use whatever dump program
you want, as long as it generates an estimate to stdout that Amanda can
parse and sends the actual dump image to stdout.

Note also that compression is a separate step Amanda will tack on to the
stdout of this script (or not).  If you want to do your own compression,
add it to the script and tell Amanda "compress none".

Then test it at least once :-).  If you set the DEBUG environment variable
to "print" (or "echo" -- same difference), the script will run but not
execute anything (although you'll have to set up your own functions to
follow the examples in the code).  Here is a sample test line I used
(using ksh as a login shell):

  DEBUG=print gtar-wrapper.ksh \
	      --directory /home/HomeAC \
	      --file - \
	      .

Amanda will pass whatever you set in disklist as the --directory argument.
To test estimates, change "-" to "/dev/null" for the --file argument.

Amanda passes a mess of other parameters, but only --directory and
--file are of interest to the script.  If you do any significant argument
processing, make sure you don't loose anything (see function do_home in
the script).

I think.  :-)

John R. Jackson, Technical Software Specialist, jrj AT purdue DOT edu

** Additional notes -- 12-Sep-01 **

Fixed some truly silly bugs.  Rewrote enough of the code to be able to
run under bash as well as ksh.