[pgpool-hackers: 2392] Re: Problems with the relative paths in daemon mode

[Tatsuo Ishii]

Good catch! Please go ahead.

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp

> Hi
> 
> Pgpool-II does not properly handle the relative paths especially when the
> pgpool.conf file is explicitly specified using the command line (-f switch)
> while its patch is given relative to the current directory.
> 
> For example:
> 
> Suppose we invoke pgpool-II from "/home/work/installed/pgpool/bin" directory
> 
> $ pwd
> /home/work//installed/pgpool/bin
> $ ./pgpool -f simple_conf/pgpool.conf
> 
> Now we are expecting here is that the Pgpool-II will look for pgpool.conf
> file in the
> /home/work/installed/pgpool/bin/simple_conf/ directory, which it does
> correctly :-), and also latter in the startup phase when it will require
> the pool_passwd file it will look in the same (
> /home/work/installed/pgpool/bin/simple_conf/)directory.
> So in the code what Pgpool-II does is, it take out the directory portion
> from the command line option provided to it for specifying the pgpool.conf
> file and look for the pool_passwd file in that directory. which in this
> case is just simple_conf/
> 
> Now the problem here is since the pgpool.conf path used in the command line
> option was a relative path, so it will only be able to go to the correct
> directory location if the current directory of Pgpool-II remains the same
> from where it was invoked from.
> 
> And since we do not change the current directory when Pgpool-II is started
> with "-n" switch ( non daemon mode) so everything works as expected in that
> mode.
> But when the Pgpool-II is started in the daemon mode the daemonize()
> function changes the current directory to "/"
> 
> main.c:380 if(chdir("/"))
> 
> and after that all relative path becomes invalid and Pgpool-II will start
> looking for files in invalid or non-existent location. which as per our
> example in daemon mode it will try to find the pool_passwd file in
> 
> /simple_conf/pool_passed
> 
> instead of
> 
> /home/work//installed/pgpool/bin/simple_conf/pool_passwd
> The solution to this is to convert the relative path of the pgpool.conf to
> the absolute path at the startup and later use that absolute path for all
> other path calculations.
> 
> If you do not have any reservation, than I will start working on the fix.
> 
> Thanks
> Best Regards
> Muhammad Usama