Add _states/_modules for tablespaces and add tablespace support to formula

Add temporary states/modules for handling tablespaces in Postgresql. These will
be fed back upstream, but they can live here for now.

Add support for the states/modules to the formula.

_states/postgres_tablespace.py

@@ -0,0 +1,140 @@
+'''
+Management of PostgreSQL tablespace
+==================================
+The postgres_tablespace module is used to create and manage Postgres
+tablespaces.
+Tablespaces can be set as either absent or present.
+.. code-block:: yaml
+    ssd-tablespace:
+      postgres_tablespace.present:
+        - name: indexes
+        - path:
+'''
+from __future__ import absolute_import
+
+
+def __virtual__():
+    '''
+    Only load if the postgres_ext module is present
+    '''
+    return 'postgres_ext.tablespace_exists' in __salt__
+
+def present(name,
+            directory,
+            options=None,
+            owner=None,
+            user=None,
+            maintenance_db=None,
+            db_password=None,
+            db_host=None,
+            db_port=None,
+            db_user=None):
+    '''
+    Ensure that the named tablespace is present with the specified properties.
+    For more information about all of these options see man create_tablespace(1)
+    name
+        The name of the tablespace to manage
+    directory
+        The directory where the tablespace will be located
+    db_user
+        database username if different from config or defaul
+    db_password
+        user password if any password for a specified user
+    db_host
+        Database host if different from config or default
+    db_port
+        Database port if different from config or default
+    user
+        System user all operations should be performed on behalf of
+        .. versionadded:: Beryllium
+    '''
+    ret = {'name': name,
+           'changes': {},
+           'result': True,
+           'comment': 'Tablespace {0} is already present'.format(name)}
+    dbargs = {
+        'maintenance_db': maintenance_db,
+        'runas': user,
+        'host': db_host,
+        'user': db_user,
+        'port': db_port,
+        'password': db_password,
+    }
+    tblspaces = __salt__['postgres_ext.tablespace_list'](**dbargs)
+    if name not in tblspaces:
+        # not there, create it
+        if __opts__['test']:
+            ret['result'] = None
+            ret['comment'] = 'Tablespace {0} is set to be created'.format(name)
+            return ret
+        if __salt__['postgres_ext.tablespace_create'](name, directory, **dbargs):
+            ret['comment'] = 'The tablespace {0} has been created'.format(name)
+            ret['changes'][name] = 'Present'
+        return ret
+
+    # already exists, make sure it's got the right path
+    if tblspaces[name]['Location'] != directory:
+        ret['comment'] = 'Tablespace {0} isn\'t at the right path'.format(
+            name)
+        ret['result'] = False
+        return ret # This isn't changeable, they need to remove/remake
+
+    if (not owner and not tblspaces[name]['Owner'] == owner):
+        if __salt__['postgres_ext.tablespace_alter'](name, new_owner=owner):
+            ret['comment'] = 'Tablespace {0} owner changed'.format(name)
+            ret['result'] = True
+
+    return ret
+
+
+def absent(name,
+           user=None,
+           maintenance_db=None,
+           db_password=None,
+           db_host=None,
+           db_port=None,
+           db_user=None):
+    '''
+    Ensure that the named database is absent
+    name
+        The name of the database to remove
+    db_user
+        database username if different from config or defaul
+    db_password
+        user password if any password for a specified user
+    db_host
+        Database host if different from config or default
+    db_port
+        Database port if different from config or default
+    user
+        System user all operations should be performed on behalf of
+        .. versionadded:: Beryllium
+    '''
+    ret = {'name': name,
+           'changes': {},
+           'result': True,
+           'comment': ''}
+
+    db_args = {
+        'maintenance_db': maintenance_db,
+        'runas': user,
+        'host': db_host,
+        'user': db_user,
+        'port': db_port,
+        'password': db_password,
+    }
+    #check if tablespace exists and remove it
+    if __salt__['postgres_ext.tablespace_exists'](name, **db_args):
+        if __opts__['test']:
+            ret['result'] = None
+            ret['comment'] = 'Tablespace {0} is set to be removed'.format(name)
+            return ret
+        if __salt__['postgres_ext.tablespace_remove'](name, **db_args):
+            ret['comment'] = 'Tablespace {0} has been removed'.format(name)
+            ret['changes'][name] = 'Absent'
+            return ret
+
+    # fallback
+    ret['comment'] = 'Tablespace {0} is not present, so it cannot ' \
+                     'be removed'.format(name)
+    return ret