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Re: running logical replication as the subscription owner

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: Ajin Cherian <itsajin@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Noah Misch <noah@leadboat.com>, Jeff Davis <pgsql@j-davis.com>, Jelte Fennema <postgres@jeltef.nl>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, Andres Freund <andres@anarazel.de>
Date: 2023-06-04T18:14:56Z
Lists: pgsql-hackers 
On Fri, May 26, 2023 at 6:18 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>
> On Thu, May 25, 2023 at 5:41 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> I've attached the updated patch. Please review it.
>

Few comments:
1.
+ /* get the owner for ACL and RLS checks */
+ run_as_owner = MySubscription->runasowner;
+ checkowner = run_as_owner ? MySubscription->owner : rel->rd_rel->relowner;
+
  /*
  * Check that our table sync worker has permission to insert into the
  * target table.
  */
- aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
+ aclresult = pg_class_aclcheck(RelationGetRelid(rel), checkowner,

One thing that slightly worries me about this change is that we
started to check the permission for relowner before even ensuring that
we can switch to relowner. See checks in SwitchToUntrustedUser(). If
we want to first ensure that we can switch to relowner then I think we
should move this permission-checking code before we try to copy the
table.

2. In the commit message, the link for discussion
"https://postgr.es/m/CAA4eK1KfZcRq7hUqQ7WknP+u=08+6MevVm+2W5RrAb+DTxrdww@mail.gmail.com"
is slightly misleading. Can we instead use
"https://www.postgresql.org/message-id/CAA4eK1L%3DqzRHPEn%2BqeMoKQGFBzqGoLBzt_ov0A89iFFiut%2BppA%40mail.gmail.com"?

-- 
With Regards,
Amit Kapila.

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Honor run_as_owner option in tablesync worker.

  2. Document new pg_subscription columns.

  3. Add a run_as_owner option to subscriptions.

  4. Perform logical replication actions as the table owner.

  5. Add new predefined role pg_create_subscription.

  6. Respect permissions within logical replication.

  7. Empty search_path in logical replication apply worker and walsender.

  8. Empty search_path in Autovacuum and non-psql/pgbench clients.