Re: Proposing COPY .. WITH PERMISSIVE - Mailing list pgsql-hackers
From | dinesh kumar |
---|---|
Subject | Re: Proposing COPY .. WITH PERMISSIVE |
Date | |
Msg-id | CALnrH7o+G0-2KuP3QB7gG+WmMjDvsM1VobovUgMK4=0PjE5TbQ@mail.gmail.com Whole thread Raw |
In response to | Re: Proposing COPY .. WITH PERMISSIVE (Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>) |
Responses |
Re: Proposing COPY .. WITH PERMISSIVE
|
List | pgsql-hackers |
On Wed, Sep 2, 2015 at 1:19 PM, Stefan Kaltenbrunner <stefan@kaltenbrunner.cc> wrote:
Yes, I agree with you. We shouldn't embed the unix style access model into COPY.
--
On 09/02/2015 10:10 PM, dinesh kumar wrote:
> On Tue, Sep 1, 2015 at 10:58 PM, Stefan Kaltenbrunner
> <stefan@kaltenbrunner.cc <mailto:stefan@kaltenbrunner.cc>> wrote:
>
> On 07/25/2015 03:38 AM, dinesh kumar wrote:
> >
> >
> > On Fri, Jul 24, 2015 at 10:22 AM, Robert Haas <robertmhaas@gmail.com <mailto:robertmhaas@gmail.com>
> > <mailto:robertmhaas@gmail.com <mailto:robertmhaas@gmail.com>>> wrote:
> >
> > On Thu, Jul 23, 2015 at 8:15 PM, dinesh kumar
> > <dineshkumar02@gmail.com <mailto:dineshkumar02@gmail.com>
> <mailto:dineshkumar02@gmail.com <mailto:dineshkumar02@gmail.com>>>
> wrote:
> > > On Thu, Jul 23, 2015 at 9:21 AM, Robert Haas
> > <robertmhaas@gmail.com <mailto:robertmhaas@gmail.com>
> <mailto:robertmhaas@gmail.com <mailto:robertmhaas@gmail.com>>> wrote:
> > >>
> > >> On Thu, Jul 23, 2015 at 12:19 PM, dinesh kumar
> > <dineshkumar02@gmail.com <mailto:dineshkumar02@gmail.com>
> <mailto:dineshkumar02@gmail.com <mailto:dineshkumar02@gmail.com>>>maybe - but having a fixed "default" is very different from baking a> > >> wrote:
> > >> > Sorry for my unclear description about the proposal.
> > >> >
> > >> > "WITH PERMISSIVE" is equal to our existing behavior. That
> is, chmod=644
> > >> > on
> > >> > the created files.
> > >> >
> > >> > If User don't specify "PERMISSIVE" as an option, then the
> chmod=600 on
> > >> > created files. In this way, we can restrict the other
> users from reading
> > >> > these files.
> > >>
> > >> There might be some benefit in allowing the user to choose the
> > >> permissions, but (1) I doubt we want to change the default
> behavior
> > >> and (2) providing only two options doesn't seem flexible
> enough.
> > >>
> > >
> > > Thanks for your inputs Robert.
> > >
> > > 1) IMO, we will keep the exiting behavior as it is.
> > >
> > > 2) As the actual proposal talks about the permissions of
> group/others. So,
> > > we can add few options as below to the WITH clause
> > >
> > > COPY
> > > ..
> > > ..
> > > WITH
> > > [
> > > NO
> > > (READ,WRITE)
> > > PERMISSION TO
> > > (GROUP,OTHERS)
> > > ]
> >
> > If we're going to do anything here, it should use COPY's
> > extensible-options syntax, I think.
> >
> >
> > Thanks Robert. Let me send a patch for this.
>
>
> how are you going to handle windows or unix ACLs here?
> Its permission model is quite different and more powerful than (non-acl
> based) unix in general, handling this in a flexible way might soon get
> very complicated and complex for limited gain...
>
>
> Hi Stefan,
>
> I had the same questions too. But, I believe, our initdb works in these
> cases, after creating the data cluster. Isn't ?
classic unix permission concept of user/group/world^others into actual
DDL or into a COPY option. The proposed syntax might make some sense to
a admin used to a unix style system but it is likely utterly
incomprehensible to somebody who is used to (windows style) ACLs.
I dont have a good answer on what to do else atm but I dont think we
should embedded traditional/historical unix permission models in our
grammer unless really really needed..
Yes, I agree with you. We shouldn't embed the unix style access model into COPY.
COPY's default behaviour umask 644 on output files, which is giving read access to other users.
I see, there is a good reason behind it. Also, it would be good to have a control on the READ ACCESS of a file, where we can secure our dump files, from the non instance ownership users.
I see, there is a good reason behind it. Also, it would be good to have a control on the READ ACCESS of a file, where we can secure our dump files, from the non instance ownership users.
Adding a trivial patch to control this read ACL.
--Sample Test Case
--Default behaviour
postgres=# COPY test_table TO '/tmp/readacs.txt';
COPY 1000
$ ls -l /tmp/readacs.txt
-rw-r--r-- /tmp/test1.txt
COPY 1000
$ ls -l /tmp/readacs.txt
-rw-r--r-- /tmp/test1.txt
--With applied patch
postgres=# COPY test_table TO '/tmp/noreadacs.txt' NO READ ACCESS;
COPY 1000
postgres=# COPY test_table TO '/tmp/noreadacs.txt' NO READ ACCESS;
COPY 1000
$ ls -l /tmp/noreadacs.txt
-rw------- /tmp/noreadacs.txt
We can also use "PROGRAM 'cat > Output.csv' " to achieve this "NO READ ACCESS", since the program is always running as a instance owner.
Let me know your inputs and thoughts.
Stefan
--
Attachment
pgsql-hackers by date: