Refactor SSL setup to use CA to sign certificates

Users can now use Packstack generated CA or provide Subordinate CA to packstack
to sign certificates used by OpenStack.

Resolves: rhbz#1163866

Change-Id: Idd89dbb7f197a194fd87576be6d95a75d059231e

packstack/installer/validators.py

@@ -32,7 +32,8 @@ __all__ = ('ParamValidationError', 'validate_integer', 'validate_float',
            'validate_multi_ip', 'validate_file', 'validate_ping',
            'validate_multi_ping', 'validate_ssh', 'validate_multi_ssh',
            'validate_sshkey', 'validate_ldap_url', 'validate_ldap_dn',
-           'validate_export', 'validate_multi_export')
+           'validate_export', 'validate_multi_export',
+           'validate_writeable_directory')
 
 
 def validate_integer(param, options=None):
@@ -197,6 +198,23 @@ def validate_file(param, options=None):
         raise ParamValidationError(msg % param)
 
 
+def validate_writeable_directory(param, options=None):
+    """
+    Raises ParamValidationError if provided directory does not exist or
+    is not writeable.
+    """
+    if not param:
+        return
+
+    options = options or []
+    if not ((os.path.isdir(param) and os.access(param, os.W_OK)) or
+            os.access(os.path.join(param, os.pardir), os.W_OK)):
+        logging.debug('validate_writeable_directory(%s, options=%s) failed.' %
+                      (param, options))
+        msg = 'Given directory does not exist or is not writeable: %s'
+        raise ParamValidationError(msg % param)
+
+
 def validate_ping(param, options=None):
     """
     Raises ParamValidationError if provided host does not answer to ICMP