Thread: Prevent pg_basebackup -Fp -D -?

Right now, if you use

pg_basebackup -Ft -D -

you get a tarfile, written to stdout, for redirection.

However, if you use:

pg_basebackup -Fp -D -

you get a plaintext (unpackaged) backup, in a directory called "-".

I can't think of a single usecase where this is a good idea. Therefor,
I would suggest we simply throw an error in this case, instead of
creating the directory. Only for the specific case of specifying
exactly "-" as a directory.

Comments?

Also, if we do that, is this something we should consider
backpatchable? It's not strictly speaking a bugfix, but I'd say it
fixes some seriously annoying behavior.


-- Magnus HaganderMe: http://www.hagander.net/Work: http://www.redpill-linpro.com/

On Wed, Oct 2, 2013 at 11:31 PM, Magnus Hagander <magnus@hagander.net> wrote:
> Right now, if you use
>
> pg_basebackup -Ft -D -
>
> you get a tarfile, written to stdout, for redirection.
>
> However, if you use:
>
> pg_basebackup -Fp -D -
>
> you get a plaintext (unpackaged) backup, in a directory called "-".
>
> I can't think of a single usecase where this is a good idea. Therefor,
> I would suggest we simply throw an error in this case, instead of
> creating the directory. Only for the specific case of specifying
> exactly "-" as a directory.
>
> Comments?
Isn't this a non-problem? This behavior is in line with the
documentation, so I would suspected that if directory name is
specified as "-" in plain mode, it should create the folder with this
name.
Do you consider having a folder of this name an annoyance?

> Also, if we do that, is this something we should consider
> backpatchable? It's not strictly speaking a bugfix, but I'd say it
> fixes some seriously annoying behavior.
This would change the spec of pg_basebackup, so no? Does the current
behavior have potential security issues?

My 2c. Regards,
-- 
Michael

On 10/02/2013 05:47 PM, Michael Paquier wrote:
> On Wed, Oct 2, 2013 at 11:31 PM, Magnus Hagander <magnus@hagander.net> wrote:
>> Right now, if you use
>>
>> pg_basebackup -Ft -D -
>>
>> you get a tarfile, written to stdout, for redirection.
>>
>> However, if you use:
>>
>> pg_basebackup -Fp -D -
>>
>> you get a plaintext (unpackaged) backup, in a directory called "-".
>>
>> I can't think of a single usecase where this is a good idea. Therefor,
>> I would suggest we simply throw an error in this case, instead of
>> creating the directory. Only for the specific case of specifying
>> exactly "-" as a directory.
>>
>> Comments?

I can see fixing this going forwards, but it doesn't seem worth
backpatching.

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com

<p dir="ltr"><br /> On Oct 3, 2013 2:47 AM, "Michael Paquier" <<a
href="mailto:michael.paquier@gmail.com">michael.paquier@gmail.com</a>>wrote:<br /> ><br /> > On Wed, Oct 2,
2013at 11:31 PM, Magnus Hagander <<a href="mailto:magnus@hagander.net">magnus@hagander.net</a>> wrote:<br /> >
>Right now, if you use<br /> > ><br /> > > pg_basebackup -Ft -D -<br /> > ><br /> > > you
geta tarfile, written to stdout, for redirection.<br /> > ><br /> > > However, if you use:<br /> >
><br/> > > pg_basebackup -Fp -D -<br /> > ><br /> > > you get a plaintext (unpackaged) backup, in
adirectory called "-".<br /> > ><br /> > > I can't think of a single usecase where this is a good idea.
Therefor,<br/> > > I would suggest we simply throw an error in this case, instead of<br /> > > creating the
directory.Only for the specific case of specifying<br /> > > exactly "-" as a directory.<br /> > ><br />
>> Comments?<br /> > Isn't this a non-problem? This behavior is in line with the<br /> > documentation, so
Iwould suspected that if directory name is<br /> > specified as "-" in plain mode, it should create the folder with
this<br/> > name.<br /> > Do you consider having a folder of this name an annoyance?<p dir="ltr">Yes, that is
exactlythe point - i do consider that an annoyance, and i don't see the use case where you'd actually want it. I bet
100%of the users of that have been accidental, thinking they'd get the pipe, not the directory. <br /><p dir="ltr">>
>Also, if we do that, is this something we should consider<br /> > > backpatchable? It's not strictly speaking
abugfix, but I'd say it<br /> > > fixes some seriously annoying behavior.<br /> > This would change the spec
ofpg_basebackup, so no? Does the current<br /> > behavior have potential security issues?<p dir="ltr">No, there are
nosecurity issues that I can see. Just annoyance. And yes, I guess it would change the spec, so backpatching might be a
badidea.. <br /><p dir="ltr">/Magnus  

On Thu, Oct  3, 2013 at 06:50:57AM +0200, Magnus Hagander wrote:
> 
> On Oct 3, 2013 2:47 AM, "Michael Paquier" <michael.paquier@gmail.com> wrote:
> >
> > On Wed, Oct 2, 2013 at 11:31 PM, Magnus Hagander <magnus@hagander.net> wrote:
> > > Right now, if you use
> > >
> > > pg_basebackup -Ft -D -
> > >
> > > you get a tarfile, written to stdout, for redirection.
> > >
> > > However, if you use:
> > >
> > > pg_basebackup -Fp -D -
> > >
> > > you get a plaintext (unpackaged) backup, in a directory called "-".
> > >
> > > I can't think of a single usecase where this is a good idea. Therefor,
> > > I would suggest we simply throw an error in this case, instead of
> > > creating the directory. Only for the specific case of specifying
> > > exactly "-" as a directory.
> > >
> > > Comments?
> > Isn't this a non-problem? This behavior is in line with the
> > documentation, so I would suspected that if directory name is
> > specified as "-" in plain mode, it should create the folder with this
> > name.
> > Do you consider having a folder of this name an annoyance?
> 
> Yes, that is exactly the point - i do consider that an annoyance, and i don't
> see the use case where you'd actually want it. I bet 100% of the users of that
> have been accidental, thinking they'd get the pipe, not the directory.
> 
> > > Also, if we do that, is this something we should consider
> > > backpatchable? It's not strictly speaking a bugfix, but I'd say it
> > > fixes some seriously annoying behavior.
> > This would change the spec of pg_basebackup, so no? Does the current
> > behavior have potential security issues?
> 
> No, there are no security issues that I can see. Just annoyance. And yes, I
> guess it would change the spec, so backpatching might be a bad idea..

Has this been fixed?  If so, I don't see it.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + Everyone has their own god. +