Re: pg_upgrade and umask

On Fri, Mar 09, 2012 at 10:41:53AM -0500, Tom Lane wrote:
> Bruce Momjian <bruce(at)momjian(dot)us> writes:
> > The problem is that these files are being created often by shell
> > redirects, e.g. pg_dump -f out 2> log_file. There is no clean way to
> > control the file creation permissions in this case --- only umask gives
> > us a process-level setting. Actually, one crafty idea would be to do
> > the umask only when I exec something, and when I create the initial
> > files with the new banner you suggested. Let me look into that.
>
> You could create empty log files with the desired permissions, and then
> do the execs with >>log_file, and thereby not have to globally change
> umask.

Yes, that is what I have done, with the attached patch. I basically
wrapped the fopen call with umask calls, and have the system() call
wrapped too. That takes care of all the files pg_upgrade creates.

> > Frankly, the permissions are already being modified by the default
> > umask, e.g. 0022. Do we want a zero umask?
>
> I'm not so worried about default umask; nobody's complained yet about
> wrong permissions on pg_upgrade output files. But umask 077 would be
> likely to do things like get rid of group access to postgresql.conf,
> which some people intentionally set.

Yes, that was my conclusion too, but I wanted to ask. FYI, this doesn't
affect the install itself, just what pg_upgrade changes, and it doesn't
touch postgresql.conf, but, as you, I am worried there might be
long-term problems with an aggressive umask that covered the entire
executable.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +