Re: Non-superuser subscription owners

Mark Dilger <mark.dilger@enterprisedb.com>

From: Mark Dilger <mark.dilger@enterprisedb.com>
To: Jeff Davis <pgsql@j-davis.com>
Cc: Andrew Dunstan <andrew@dunslane.net>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Robert Haas <robertmhaas@gmail.com>
Date: 2021-11-17T23:07:10Z
Lists: pgsql-hackers

> On Nov 17, 2021, at 1:10 PM, Jeff Davis <pgsql@j-davis.com> wrote:
> 
> I think you misunderstood the idea: not using predefined roles, just
> plain old ordinary GRANT on a subscription object to ordinary roles.
> 
>   GRANT REFRESH ON SUBSCRIPTION sub1 TO nonsuper;
> 
> This should be easy enough because the subscription is a real object,
> right?

/*
 * Grantable rights are encoded so that we can OR them together in a bitmask.
 * The present representation of AclItem limits us to 16 distinct rights,
 * even though AclMode is defined as uint32.  See utils/acl.h.
 *
 * Caution: changing these codes breaks stored ACLs, hence forces initdb.
 */
typedef uint32 AclMode;         /* a bitmask of privilege bits */

#define ACL_INSERT      (1<<0)  /* for relations */
#define ACL_SELECT      (1<<1)
#define ACL_UPDATE      (1<<2)
#define ACL_DELETE      (1<<3)
#define ACL_TRUNCATE    (1<<4)
#define ACL_REFERENCES  (1<<5)
#define ACL_TRIGGER     (1<<6)
#define ACL_EXECUTE     (1<<7)  /* for functions */
#define ACL_USAGE       (1<<8)  /* for languages, namespaces, FDWs, and
                                 * servers */
#define ACL_CREATE      (1<<9)  /* for namespaces and databases */
#define ACL_CREATE_TEMP (1<<10) /* for databases */
#define ACL_CONNECT     (1<<11) /* for databases */


We only have 4 values left in the bitmask, and I doubt that burning those slots for multiple new types of rights that only have meaning for subscriptions is going to be accepted.  For full disclosure, I'm proposing adding ACL_SET and ACL_ALTER_SYSTEM in another patch and my proposal there could get shot down for the same reasons, but I think your argument would be even harder to defend.  Maybe others feel differently.

—
Mark Dilger
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company






Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Fix possible crash in tablesync worker.

  2. Display 'password_required' option for \dRs+ command.

  3. Restart the apply worker if the 'password_required' option is changed.

  4. Fix possible logical replication crash.

  5. Add new predefined role pg_create_subscription.

  6. Expand AclMode to 64 bits

  7. More cleanup of a2ab9c06ea.

  8. Respect permissions within logical replication.

  9. Improve table locking behavior in the face of current DDL.