Re: Trouble starting postgresql

Alan M. Evans wrote:

On Tue, 2006-05-30 at 09:10, Paul Howarth wrote:
[ ... ]

If that's all you have, it shouldn't be difficult to fix.

Set yourself up for making local policy modules:

# yum install checkpolicy
# cd /root
# mkdir selinux.local
# cd selinux.local
# chcon -R -t usr_t .
# ln -s /usr/share/selinux/devel/Makefile .

Make a local policy module for this issue, in this directory:

1. Create a file postgresql.te with this content:

module postgresql 0.1;

require {
         class dir search;
         class lnk_file read;

         type home_root_t;
         type postgresql_t;
         type var_lib_t;
};

# Allow postgresql to read /var/lib/pgsql -> /home/pgsql symlink
# if present
allow postgresql_t var_lib_t:lnk_file read;

# Allow postgresql to search directory /home
allow postgresql_t home_root_t:dir search;

2. Create a file postgresql.fc with this content:

/home/pgsql -d gen_context(system_u:object_r:var_lib_t,s0) /home/pgsql/data(/.*)? gen_context(system_u:object_r:postgresql_db_t,s0) /home/pgsql/pgstartup.log -- gen_context(system_u:object_r:postgresql_log_t,s0)

(that's three long lines)

3. Create an empty postgresql.if file:

# touch postgresql.if

4. Build the policy module

# make

Install your new policy module:

# semodule -i postgresql.pp

Fix file contexts:

# restorecon -Rv /home/pgsql

Hopefully that should get you going in enforcing mode.

Well, that restorecon set all the contexts back to user_home_t. Ugh.

Ugh indeed. My fix is incomplete. Can you post the output of:
# semanage fcontext -l | grep pgsql

I trust that /home/pgsql is not some user's home directory?

After recursively setting the data directory to postgresql_db_t and the
logfile to postgresql_log_t, service starts up without complaint. So
then:

  postgresql started... check
  database located under /home/pgsql... check
  SELinux enforcing... yep
  postgresql service not excluded... yes
  read and write data to db... YES!

Excellent. I presume I should keep these SELinux policy source files in
a safe place in case this configuration is required again.

Thank you so much for your assistance! I have one final question. Do you
have any recommendations for decent documentation on SELinux
administration? Online is alright, but book recommendations are
perfectly welcome.

I hope to avoid having to go through this in the future. My goal is
really to understand the process. Right now, all I can do is describe
the problem and hope someone can walk me through the solution as you
have done. (I learn well from examples, so I know much more now that
I've at least gone through it.)

Paul.