On Thu, Sep 1, 2022 at 8:23 PM Peter J. Holzer <hjp-pgsql@xxxxxx> wrote:
>
> On 2022-09-01 18:16:14 -0400, Tom Lane wrote:
> > Jeffrey Walton <noloader@xxxxxxxxx> writes:
> > > We are having a heck of a time getting PostreSQL utilities to honor
> > > home directories. For example, when I execute this script:
> >
> > > sudo -H -u postgres PGPASSWORD=${password} \
> > > psql -h "${hostname}" -U "${username}" -d "${database}" \
> > > --command="..."
> >
> > > It produces failures:
> >
> > > could not change directory to "/home/jwalton/godojo": Permission denied
> >
> > You've left out quite a lot of information here ... like what
> > connection that directory has to do with anything. Is it your
> > current directory when you invoke this command?
>
> Probably. See below.
>
>
> > If so, a plausible explanation is that psql is trying to chase a
> > symlink to somewhere, which involves some chdir's so it can resolve
> > the symlink correctly, and afterwards it has to change back to
> > where it started --- which would fail if it can't look up that
> > directory.
> >
> > Why it's trying to resolve a symlink isn't apparent though.
> > Is the "psql" you're invoking a symlink to somewhere?
>
> It is on Debian/Ubuntu:
>
> % ls -l =psql
> lrwxrwxrwx 1 root root 37 Aug 11 11:25 /bin/psql -> ../share/postgresql-common/pg_wrapper*
>
> (this is the pgdg package)
>
> I do get the same message, but psql seems to start normally:
>
> % sudo -u postgres -H psql
> could not change directory to "/home/hjp/tmp/t": Permission denied
> Null display is "(∅)".
> Line style is unicode.
> Border style is 2.
> Unicode border line style is "double".
> Timing is on.
> Expanded display is used automatically.
> psql (13.8 (Ubuntu 13.8-1.pgdg20.04+1), server 11.17 (Ubuntu 11.17-1.pgdg20.04+1))
> Type "help" for help.
>
> postgres=#
>
> However, when I start a shell, I see that the directory has been
> changed:
>
> postgres=# \!
> postgres@trintignant:/usr/lib/postgresql/13/bin$
>
>
> However, the symlink doesn't seem to be the culprit. If I run
>
> % sudo -u postgres -H /usr/lib/postgresql/13/bin/psql
>
> (which is not a symlink)
>
> I get the same behaviour. So it seems that psql changes to its basedir
> and then can't change back again.
>
> And sure enough, strace shows:
>
> chdir("/usr/lib/postgresql/13/bin") = 0
> chdir("/home/hjp/tmp/t") = 0
> chdir("/usr/lib/postgresql/13/bin") = 0
> chdir("/home/hjp/tmp/t") = 0
>
> (this is without sudo, because I can't strace that)
Thanks Peter.
I guess there is no way to avoid the problem.
And if interested, others have trouble, too. I found this when
searching for a resolution:
https://github.com/ANXS/postgresql/issues/499 .
Jeff
