Chapter 10. PostgreSQL
PostgreSQL is an Object-Relational database management system (DBMS).[8]
In Red Hat Enterprise Linux 6, the postgresql-server package provides PostgreSQL. Run the
rpm -q postgresql-server
command to see if the postgresql-server package is installed. If it is not installed, run the following command as the root user to install it:
~]# yum install postgresql-server
10.1. PostgreSQL and SELinux
When PostgreSQL is enabled, it runs confined by default. Confined processes run in their own domains, and are separated from other confined processes. If a confined process is compromised by an attacker, depending on SELinux policy configuration, an attacker's access to resources and the possible damage they can do is limited. The following example demonstrates the PostgreSQL processes running in their own domain. This example assumes the postgresql-server package is installed:
- Run the
getenforce
command to confirm SELinux is running in enforcing mode:~]$
getenforce
EnforcingThegetenforce
command returnsEnforcing
when SELinux is running in enforcing mode. - Run the
service postgresql start
command as the root user to startpostgresql
:~]#
service postgresql start
Starting postgresql service: [ OK ] - Run the
ps -eZ | grep postgres
command to view thepostgresql
processes:~]$
ps -eZ | grep postgres
unconfined_u:system_r:postgresql_t:s0 395 ? 00:00:00 postmaster unconfined_u:system_r:postgresql_t:s0 397 ? 00:00:00 postmaster unconfined_u:system_r:postgresql_t:s0 399 ? 00:00:00 postmaster unconfined_u:system_r:postgresql_t:s0 400 ? 00:00:00 postmaster unconfined_u:system_r:postgresql_t:s0 401 ? 00:00:00 postmaster unconfined_u:system_r:postgresql_t:s0 402 ? 00:00:00 postmasterThe SELinux context associated with thepostgresql
processes isunconfined_u:system_r:postgresql_t:s0
. The second last part of the context,postgresql_t
, is the type. A type defines a domain for processes and a type for files. In this case, thepostgresql
processes are running in thepostgresql_t
domain.