On Tue, Jun 25, 2024 at 11:28:18AM -0500, Nathan Bossart wrote:
> On Tue, Jun 25, 2024 at 12:16:30PM -0400, Robert Haas wrote:
>> pg_database_owner is a predefined role for which membership consists,
>> implicitly, of the current database owner. It cannot be granted
>> membership in any role, and no role can be granted membership in
>> pg_database_owner. However, like any role, it can own objects or
>> receive grants of access privileges. Consequently, once
>> pg_database_owner has rights within a template database, each owner of
>> a database instantiated from that template will exercise those rights.
>> Initially, this role owns the public schema, so each database owner
>> governs local use of the schema.
>
> The main difference between this and the existing documentation is that the
> sentence on membership has been rephrased and moved to earlier in the
> paragraph. I think this helps the logical flow a bit. We first talk about
> implicit membership, then explicit membership, then we talk about
> privileges and the consequences of those privileges, and finally we talk
> about the default privileges. So, WFM.
I used this in v4 (with some minor changes). I've copied it here to ease
review.
pg_database_owner always has exactly one implicit member: the current
database owner. It cannot be granted membership in any role, and no
role can be granted membership in pg_database_owner. However, like any
other role, it can own objects and receive grants of access privileges.
Consequently, once pg_database_owner has rights within a template
database, each owner of a database instantiated from that template will
possess those rights. Initially, this role owns the public schema, so
each database owner governs local use of that schema.
--
nathan
>From 515d8b8f17c9cc6b5fe53e2dedcac2c282537315 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nat...@postgresql.org>
Date: Tue, 18 Jun 2024 11:38:40 -0500
Subject: [PATCH v4 1/1] revamp predefined roles documentation
---
doc/src/sgml/config.sgml | 2 +-
doc/src/sgml/monitoring.sgml | 4 +-
doc/src/sgml/ref/checkpoint.sgml | 2 +-
doc/src/sgml/ref/reindex.sgml | 2 +-
doc/src/sgml/user-manag.sgml | 340 ++++++++++++++++---------------
5 files changed, 186 insertions(+), 164 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 0c7a9082c5..03e37209e6 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -731,7 +731,7 @@ include_dir 'conf.d'
<para>
Determines the number of connection <quote>slots</quote> that are
reserved for connections by roles with privileges of the
- <link
linkend="predefined-roles-table"><literal>pg_use_reserved_connections</literal></link>
+ <xref linkend="predefined-role-pg-use-reserved-connections"/>
role. Whenever the number of free connection slots is greater than
<xref linkend="guc-superuser-reserved-connections"/> but less than or
equal to the sum of <varname>superuser_reserved_connections</varname>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index b2ad9b446f..f30c1e53fa 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -286,8 +286,8 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34
0:00 postgres: ser
other sessions, many columns will be null. Note, however, that the
existence of a session and its general properties such as its sessions user
and database are visible to all users. Superusers and roles with
privileges of
- built-in role <literal>pg_read_all_stats</literal> (see also <xref
- linkend="predefined-roles"/>) can see all the information about all
sessions.
+ built-in role <link
linkend="predefined-role-pg-monitor"><literal>pg_read_all_stats</literal></link>
+ can see all the information about all sessions.
</para>
<table id="monitoring-stats-dynamic-views-table">
diff --git a/doc/src/sgml/ref/checkpoint.sgml b/doc/src/sgml/ref/checkpoint.sgml
index 28a1d717b8..db011a47d0 100644
--- a/doc/src/sgml/ref/checkpoint.sgml
+++ b/doc/src/sgml/ref/checkpoint.sgml
@@ -53,7 +53,7 @@ CHECKPOINT
<para>
Only superusers or users with the privileges of
- the <link
linkend="predefined-roles-table"><literal>pg_checkpoint</literal></link>
+ the <xref linkend="predefined-role-pg-checkpoint"/>
role can call <command>CHECKPOINT</command>.
</para>
</refsect1>
diff --git a/doc/src/sgml/ref/reindex.sgml b/doc/src/sgml/ref/reindex.sgml
index 2942dccf1e..dcf70d14bc 100644
--- a/doc/src/sgml/ref/reindex.sgml
+++ b/doc/src/sgml/ref/reindex.sgml
@@ -305,7 +305,7 @@ REINDEX [ ( <replaceable
class="parameter">option</replaceable> [, ...] ) ] { DA
partitioned table, such commands skip the privilege checks when processing
the individual partitions. Reindexing a schema or database requires being
the
owner of that schema or database or having privileges of the
- <link linkend="predefined-roles-table"><literal>pg_maintain</literal></link>
+ <xref linkend="predefined-role-pg-maintain"/>
role. Note specifically that it's thus
possible for non-superusers to rebuild indexes of tables owned by
other users. However, as a special exception,
diff --git a/doc/src/sgml/user-manag.sgml b/doc/src/sgml/user-manag.sgml
index 07a16247d7..6fc4464519 100644
--- a/doc/src/sgml/user-manag.sgml
+++ b/doc/src/sgml/user-manag.sgml
@@ -590,101 +590,73 @@ DROP ROLE doomed_role;
and information. Administrators (including roles that have the
<literal>CREATEROLE</literal> privilege) can <command>GRANT</command> these
roles to users and/or other roles in their environment, providing those
- users with access to the specified capabilities and information.
+ users with access to the specified capabilities and information. For
+ example:
+
+<programlisting>
+GRANT pg_signal_backend TO admin_user;
+</programlisting>
</para>
+ <warning>
+ <para>
+ Care should be taken when granting these roles to ensure they are only used
+ where needed and with the understanding that these roles grant access to
+ privileged information.
+ </para>
+ </warning>
+
<para>
- The predefined roles are described in <xref
linkend="predefined-roles-table"/>.
+ The predefined roles are described below.
Note that the specific permissions for each of the roles may change in
the future as additional capabilities are added. Administrators
should monitor the release notes for changes.
- </para>
- <table tocentry="1" id="predefined-roles-table">
- <title>Predefined Roles</title>
- <tgroup cols="2">
- <colspec colname="col1" colwidth="1*"/>
- <colspec colname="col2" colwidth="2*"/>
- <thead>
- <row>
- <entry>Role</entry>
- <entry>Allowed Access</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>pg_read_all_data</entry>
- <entry>Read all data (tables, views, sequences), as if having
- <command>SELECT</command> rights on those objects, and USAGE rights on
- all schemas, even without having it explicitly. This role does not have
- the role attribute <literal>BYPASSRLS</literal> set. If RLS is being
- used, an administrator may wish to set <literal>BYPASSRLS</literal> on
- roles which this role is GRANTed to.</entry>
- </row>
- <row>
- <entry>pg_write_all_data</entry>
- <entry>Write all data (tables, views, sequences), as if having
- <command>INSERT</command>, <command>UPDATE</command>, and
- <command>DELETE</command> rights on those objects, and USAGE rights on
- all schemas, even without having it explicitly. This role does not have
- the role attribute <literal>BYPASSRLS</literal> set. If RLS is being
- used, an administrator may wish to set <literal>BYPASSRLS</literal> on
- roles which this role is GRANTed to.</entry>
- </row>
- <row>
- <entry>pg_read_all_settings</entry>
- <entry>Read all configuration variables, even those normally visible
only to
- superusers.</entry>
- </row>
- <row>
- <entry>pg_read_all_stats</entry>
- <entry>Read all pg_stat_* views and use various statistics related
extensions,
- even those normally visible only to superusers.</entry>
- </row>
- <row>
- <entry>pg_stat_scan_tables</entry>
- <entry>Execute monitoring functions that may take <literal>ACCESS
SHARE</literal> locks on tables,
- potentially for a long time.</entry>
- </row>
- <row>
- <entry>pg_monitor</entry>
- <entry>Read/execute various monitoring views and functions.
- This role is a member of <literal>pg_read_all_settings</literal>,
- <literal>pg_read_all_stats</literal> and
- <literal>pg_stat_scan_tables</literal>.</entry>
- </row>
- <row>
- <entry>pg_database_owner</entry>
- <entry>None. Membership consists, implicitly, of the current database
owner.</entry>
- </row>
- <row>
- <entry>pg_signal_backend</entry>
- <entry>Signal another backend to cancel a query or terminate its
session.</entry>
- </row>
- <row>
- <entry>pg_read_server_files</entry>
- <entry>Allow reading files from any location the database can access on
the server with COPY and
- other file-access functions.</entry>
- </row>
- <row>
- <entry>pg_write_server_files</entry>
- <entry>Allow writing to files in any location the database can access
on the server with COPY and
- other file-access functions.</entry>
- </row>
- <row>
- <entry>pg_execute_server_program</entry>
- <entry>Allow executing programs on the database server as the user the
database runs as with
- COPY and other functions which allow executing a server-side
program.</entry>
- </row>
- <row>
- <entry>pg_checkpoint</entry>
- <entry>Allow executing
- the <link linkend="sql-checkpoint"><command>CHECKPOINT</command></link>
- command.</entry>
- </row>
- <row>
- <entry>pg_maintain</entry>
- <entry>Allow executing
+ <variablelist>
+ <varlistentry id="predefined-role-pg-checkpoint" xreflabel="pg_checkpoint">
+ <term><varname>pg_checkpoint</varname></term>
+ <listitem>
+ <para>
+ <literal>pg_checkpoint</literal> allows executing the
+ <link linkend="sql-checkpoint"><command>CHECKPOINT</command></link>
command.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="predefined-role-pg-create-subscription"
xreflabel="pg_create_subscription">
+ <term><varname>pg_create_subscription</varname></term>
+ <listitem>
+ <para>
+ <literal>pg_create_subscription</literal> allows users with
+ <literal>CREATE</literal> permission on the database to issue
+ <link linkend="sql-createsubscription"><command>CREATE
SUBSCRIPTION</command></link>.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="predefined-role-pg-database-owner"
xreflabel="pg_database_owner">
+ <term><varname>pg_database_owner</varname></term>
+ <listitem>
+ <para>
+ <literal>pg_database_owner</literal> always has exactly one implicit
+ member: the current database owner. It cannot be granted membership in
+ any role, and no role can be granted membership in
+ <literal>pg_database_owner</literal>. However, like any other role, it
+ can own objects and receive grants of access privileges. Consequently,
+ once <literal>pg_database_owner</literal> has rights within a template
+ database, each owner of a database instantiated from that template will
+ possess those rights. Initially, this role owns the
+ <literal>public</literal> schema, so each database owner governs local
+ use of that schema.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="predefined-role-pg-maintain" xreflabel="pg_maintain">
+ <term><varname>pg_maintain</varname></term>
+ <listitem>
+ <para>
+ <literal>pg_maintain</literal> allows executing
<link linkend="sql-vacuum"><command>VACUUM</command></link>,
<link linkend="sql-analyze"><command>ANALYZE</command></link>,
<link linkend="sql-cluster"><command>CLUSTER</command></link>,
@@ -692,78 +664,128 @@ DROP ROLE doomed_role;
<link linkend="sql-reindex"><command>REINDEX</command></link>,
and <link linkend="sql-lock"><command>LOCK TABLE</command></link> on all
relations, as if having <literal>MAINTAIN</literal> rights on those
- objects, even without having it explicitly.</entry>
- </row>
- <row>
- <entry>pg_use_reserved_connections</entry>
- <entry>Allow use of connection slots reserved via
- <xref linkend="guc-reserved-connections"/>.</entry>
- </row>
- <row>
- <entry>pg_create_subscription</entry>
- <entry>Allow users with <literal>CREATE</literal> permission on the
- database to issue
- <link linkend="sql-createsubscription"><command>CREATE
SUBSCRIPTION</command></link>.</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
-
- <para>
- The <literal>pg_monitor</literal>, <literal>pg_read_all_settings</literal>,
- <literal>pg_read_all_stats</literal> and
<literal>pg_stat_scan_tables</literal>
- roles are intended to allow administrators to easily configure a role for the
- purpose of monitoring the database server. They grant a set of common
privileges
- allowing the role to read various useful configuration settings, statistics
and
- other system information normally restricted to superusers.
- </para>
-
- <para>
- The <literal>pg_database_owner</literal> role has one implicit,
- situation-dependent member, namely the owner of the current database. Like
- any role, it can own objects or receive grants of access privileges.
- Consequently, once <literal>pg_database_owner</literal> has rights within a
- template database, each owner of a database instantiated from that template
- will exercise those rights. <literal>pg_database_owner</literal> cannot be
- a member of any role, and it cannot have non-implicit members. Initially,
- this role owns the <literal>public</literal> schema, so each database owner
- governs local use of the schema.
- </para>
-
- <para>
- The <literal>pg_signal_backend</literal> role is intended to allow
- administrators to enable trusted, but non-superuser, roles to send signals
- to other backends. Currently this role enables sending of signals for
- canceling a query on another backend or terminating its session. A user
- granted this role cannot however send signals to a backend owned by a
- superuser. See <xref linkend="functions-admin-signal"/>.
- </para>
-
- <para>
- The <literal>pg_read_server_files</literal>,
<literal>pg_write_server_files</literal> and
- <literal>pg_execute_server_program</literal> roles are intended to allow
administrators to have
- trusted, but non-superuser, roles which are able to access files and run
programs on the
- database server as the user the database runs as. As these roles are able
to access any file on
- the server file system, they bypass all database-level permission checks
when accessing files
- directly and they could be used to gain superuser-level access, therefore
- great care should be taken when granting these roles to users.
- </para>
-
- <para>
- Care should be taken when granting these roles to ensure they are only used
where
- needed and with the understanding that these roles grant access to privileged
- information.
- </para>
-
- <para>
- Administrators can grant access to these roles to users using the
- <link linkend="sql-grant"><command>GRANT</command></link> command, for
example:
-
-<programlisting>
-GRANT pg_signal_backend TO admin_user;
-</programlisting>
+ objects.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="predefined-role-pg-monitor" xreflabel="pg_monitor">
+ <term><varname>pg_monitor</varname></term>
+ <term><varname>pg_read_all_settings</varname></term>
+ <term><varname>pg_read_all_stats</varname></term>
+ <term><varname>pg_stat_scan_tables</varname></term>
+ <listitem>
+ <para>
+ These roles are intended to allow administrators to easily configure a
+ role for the purpose of monitoring the database server. They grant a
+ set of common privileges allowing the role to read various useful
+ configuration settings, statistics, and other system information
+ normally restricted to superusers.
+ </para>
+ <para>
+ <literal>pg_monitor</literal> allows reading/executing various
+ monitoring views and functions. This role is a member of
+ <literal>pg_read_all_settings</literal>,
+ <literal>pg_read_all_stats</literal> and
+ <literal>pg_stat_scan_tables</literal>.
+ </para>
+ <para>
+ <literal>pg_read_all_settings</literal> allows reading all configuration
+ variables, even those normally visible only to superusers.
+ </para>
+ <para>
+ <literal>pg_read_all_stats</literal> allows reading all pg_stat_* views
+ and use various statistics related extensions, even those normally
+ visible only to superusers.
+ </para>
+ <para>
+ <literal>pg_stat_scan_tables</literal> allows executing monitoring
+ functions that may take <literal>ACCESS SHARE</literal> locks on tables,
+ potentially for a long time (e.g., <function>pgrowlocks(text)</function>
+ in the <xref linkend="pgrowlocks"/> extension).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="predefined-role-pg-read-all-data"
xreflabel="pg_read_all_data">
+ <term><varname>pg_read_all_data</varname></term>
+ <term><varname>pg_write_all_data</varname></term>
+ <listitem>
+ <para>
+ <literal>pg_read_all_data</literal> allows reading all data (tables,
+ views, sequences), as if having <command>SELECT</command> rights on
+ those objects and <literal>USAGE</literal> rights on all schemas. This
+ role does not bypass row-level security (RLS) policies. If RLS is being
+ used, an administrator may wish to set <literal>BYPASSRLS</literal> on
+ roles which this role is granted to.
+ </para>
+ <para>
+ <literal>pg_write_all_data</literal> allows writing all data (tables,
+ views, sequences), as if having <command>INSERT</command>,
+ <command>UPDATE</command>, and <command>DELETE</command> rights on those
+ objects and <literal>USAGE</literal> rights on all schemas. This role
+ does not bypass row-level security (RLS) policies. If RLS is being
+ used, an administrator may wish to set <literal>BYPASSRLS</literal> on
+ roles which this role is granted to.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="predefined-role-pg-read-server-files"
xreflabel="pg_read_server_files">
+ <term><varname>pg_read_server_files</varname></term>
+ <term><varname>pg_write_server_files</varname></term>
+ <term><varname>pg_execute_server_program</varname></term>
+ <listitem>
+ <para>
+ These roles are intended to allow administrators to have trusted, but
+ non-superuser, roles which are able to access files and run programs on
+ the database server as the user the database runs as. They bypass all
+ database-level permission checks when accessing files directly and they
+ could be used to gain superuser-level access. Therefore, great care
+ should be taken when granting these roles to users.
+ </para>
+ <para>
+ <literal>pg_read_server_files</literal> allows reading files from any
+ location the database can access on the server using
+ <command>COPY</command> and other file-access functions.
+ </para>
+ <para>
+ <literal>pg_write_server_files</literal> allows writing to files in any
+ location the database can access on the server using
+ <command>COPY</command> and other file-access functions.
+ </para>
+ <para>
+ <literal>pg_execute_server_program</literal> allows executing programs
+ on the database server as the user the database runs as using
+ <command>COPY</command> and other functions which allow executing a
+ server-side program.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="predefined-role-pg-signal-backend"
xreflabel="pg_signal_backend">
+ <term><varname>pg_signal_backend</varname></term>
+ <listitem>
+ <para>
+ <literal>pg_signal_backend</literal> allows signaling another backend to
+ cancel a query or terminate its session. Note that this role does not
+ permit signaling backends owned by a superuser. See
+ <xref linkend="functions-admin-signal"/>.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="predefined-role-pg-use-reserved-connections"
xreflabel="pg_use_reserved_connections">
+ <term><varname>pg_use_reserved_connections</varname></term>
+ <listitem>
+ <para>
+ <literal>pg_use_reserved_connections</literal> allows use of connection
+ slots reserved via <xref linkend="guc-reserved-connections"/>.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
</para>
-
</sect1>
<sect1 id="perm-functions">
--
2.39.3 (Apple Git-146)
