SEPGSQL - How to Fedora 16 - 17

SEPGSQL - How to Fedora 16 - 17

First, we install what we will be using.

yum install postgresql postgresql-server postgresql-contrib 

First, we want to setup sepgsql. is part of the contrib package. These modules are installed on a per database basis, so we need to initdb first

postgresql-setup initdb

Edit vim /var/lib/pgsql/data/postgresql.conf +126

shared_preload_libraries = 'sepgsql'            # (change requires restart)

Now, we need to re-label all the default postgres tables.

su postgres
export PGDATA=/var/lib/pgsql/data
for DBNAME in template0 template1 postgres; do postgres --single -F -c exit_on_error=true $DBNAME /dev/null; done

Now we can start postgresql.

systemctl start postgresql.service

Moment of truth - time to find out if we have selinux contexts in postgresql.

# su postgres
# psql -U postgres postgres -c 'select sepgsql_getcon();'
could not change directory to "/root"
(1 row)

We can create a new database. Lets call it setest. We also add an apache user for the django threads to connect to later. Finally, we want to setup password authentication, and change ownership of the new setest db to apache.

createdb setest
Enter name of role to add: apache
Shall the new role be a superuser? (y/n) n
Shall the new role be allowed to create databases? (y/n) n
Shall the new role be allowed to create more new roles? (y/n) n
psql -U postgres template1 -c "alter user apache with password 'password'"
psql -U postgres template1 -c "alter user postgres with password 'password'"
psql -U postgres template1 -c "alter database setest owner to apache"

Now we change our auth in postgres to be md5 in the file $PGDATA/pg_hdb.conf

# "local" is for Unix domain socket connections only
local   all             all                                     md5
# IPv4 local connections:
host    all             all               md5
# IPv6 local connections:
host    all             all             ::1/128                 md5

systemctl restart postgresql.service

Now you should be able to login in with a password as both users.

# psql -U postgres -W
Password for user postgres: 
psql (9.1.3)
Type "help" for help.

# psql -U apache -W setest
Password for user apache: 
psql (9.1.3)
Type "help" for help.


Lets also take this chance, to take a look at the per column and per table selinux permissions.

psql -U postgres -W setest -c "SELECT objtype, objname, label FROM pg_seclabels WHERE provider = 'selinux' AND  objtype in ('table', 'column')"

To update these

SECURITY LABEL FOR selinux ON TABLE mytable IS 'system_u:object_r:sepgsql_table_t:s0';

See also.

This is very useful, especially if combined with my next blog post.