selinux fcontext for postgres_database.present

[noelmcloughlin]

This PR fixes #186 finally.

All postgres_database.present states need a fcontext. This example from pillar.example ....

  # tablespaces to be created
  tablespaces:
    my_space:
      directory: /srv/my_tablespace            #<== new directory ....
      owner: localUser

  databases:
  ...
    db2:
      owner: 'remoteUser'
      template: 'template0'
      lc_ctype: 'en_US.UTF-8'
      lc_collate: 'en_US.UTF-8'
      tablespace: 'my_space'        #<== `postgres_database.present` will fail

Verified on Centos7 with selinux enforcing

ID: postgresql-tablespace-dir-my_space
    Function: file.directory
        Name: /srv/bob/my_tablespace
      Result: True
     Comment: Directory /srv/bob/my_tablespace is in the correct state
              Directory /srv/bob/my_tablespace updated
     Started: 13:13:06.584321
    Duration: 78.609 ms
     Changes:
----------
          ID: postgresql-tablespace-dir-my_space
    Function: pkg.installed
        Name: policycoreutils-python
      Result: True
     Comment: All specified packages are already installed
     Started: 13:13:06.663076
    Duration: 0.504 ms

          ID: postgresql-tablespace-dir-my_space
    Function: pkg.installed
        Name: selinux-policy-targeted
      Result: True
     Comment: All specified packages are already installed
     Started: 13:13:06.663680
    Duration: 0.37 ms
     Changes:
----------
          ID: postgresql-tablespace-dir-my_space
    Function: selinux.fcontext_policy_present
        Name: /srv/bob/my_tablespace(/.*)?
      Result: True
     Comment: SELinux policy for "/srv/bob/my_tablespace(/.*)?" already present with specified filetype "all files" and sel_type "postgresql_db_t".
     Started: 13:13:06.664657
    Duration: 175.454 ms
     Changes:
----------
          ID: postgresql-tablespace-dir-my_space-fcontext
    Function: selinux.fcontext_policy_applied
        Name: /srv/bob/my_tablespace
      Result: True
     Comment: SElinux policies are already applied for filespec "/srv/bob/my_tablespace"
     Started: 13:13:06.840530
    Duration: 11.444 ms

Solves the problem

          ID: postgres_database-db2
    Function: postgres_database.present
        Name: db2
      Result: True
     Comment: Database db2 is already present

[noelmcloughlin]

Complimented by saltstack/salt#50045

[aboe76]

why not base it on the grains on the system:

sudo salt-call grains.item selinux
local:
    ----------
    selinux:
        ----------
        enabled:
            True
        enforced:
            Enforcing

[noelmcloughlin]

Thanks. Which grain?

[aboe76]

@noelmcloughlin : selinux:enforced

[noelmcloughlin]

sorry okay, there is selinux grain. good idea.

[noelmcloughlin]

@aboe76 this is ready now (and much cleaner solution). Thanks.

ID: postgresql-tablespace-dir-my_space-fcontext
    Function: selinux.fcontext_policy_applied
        Name: /srv/my_tablespace
      Result: True
     Comment: 
     Started: 14:52:36.776389
    Duration: 48.675 ms
     Changes:   
              ----------
              /srv/my_tablespace:
                  ----------
                  new:
                      ----------
                      sel_type:
                          postgresql_db_t
                  old:
                      ----------
                      sel_type:
                          var_t