Re: pg_monitor role

On Mon, Feb 20, 2017 at 8:48 PM, Dave Page <dpage(at)pgadmin(dot)org> wrote:
> Further to the patch I just submitted
> (https://www.postgresql.org/message-id/CA%2BOCxow-X%3DD2fWdKy%2BHP%2BvQ1LtrgbsYQ%3DCshzZBqyFT5jOYrFw%40mail.gmail.com)
> I'd like to propose the addition of a default role, pg_monitor.
>
> The intent is to make it easy for users to setup a role for fully
> monitoring their servers, without requiring superuser level privileges
> which is a problem for many users working within strict security
> policies.
>
> At present, functions or system config info that divulge any
> installation path related info typically require superuser privileges.
> This makes monitoring for unexpected changes in configuration or
> filesystem level monitoring (e.g. checking for large numbers of WAL
> files or log file info) impossible for non-privileged roles.
>
> A similar example is the restriction on the pg_stat_activity.query
> column, which prevents non-superusers seeing any query strings other
> than their own.
>
> Using ACLs is a problem for a number of reasons:
>
> - Users often don't like their database schemas to be modified
> (cluttered with GRANTs).
> - ACL modifications would potentially have to be made in every
> database in a cluster.
> - Using a pre-defined role minimises the setup that different tools
> would have to require.
> - Not all functionality has an ACL (e.g. SHOW)
>
> Other DBMSs solve this problem in a similar way.
>
> Initially I would propose that permission be granted to the role to:
>
> - Execute pg_ls_logdir() and pg_ls_waldir()
> - Read pg_stat_activity, including the query column for all queries.
> - Allow "SELECT pg_tablespace_size('pg_global')"
> - Read all GUCs
>

Thank you for working on this.

What about granting to the role to read other statistic views such as
pg_stat_replication and pg_stat_wal_receiver? Since these informations
can only be seen by superuser the for example monitoring and
clustering tool seems to have the same concern.
And what about the diagnostic tools such as pageinspect and pgstattuple?

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center