[molecule] add support for enforcing super user privileges requirements

molecule.py

@@ -25,7 +25,8 @@ sys.path.insert(0,'molecule/')
 sys.path.insert(0,'.')
 import molecule.cmdline
 from molecule.handlers import Runner
-from molecule.utils import RUNNING_PIDS
+from molecule.utils import RUNNING_PIDS, is_super_user
+from molecule.i18n import _
 
 def kill_pids():
     for pid in RUNNING_PIDS:
@@ -36,6 +37,17 @@ if not molecule_data_order:
     molecule.cmdline.print_help()
     raise SystemExit(1)
 
+super_user = is_super_user()
+for el in molecule_data_order:
+    spec_data = molecule_data.get(el)
+    if spec_data is None:
+        # wtf
+        continue
+    super_user_required = spec_data['__plugin__'].require_super_user()
+    if super_user_required and (not super_user):
+        sys.stderr.write("%s: %s\n" % (el, _("required super user access"),))
+        raise SystemExit(1)
+
 for el in molecule_data_order:
     my = Runner(el, molecule_data.get(el))
     try:

molecule/specs/skel.py

@@ -152,6 +152,15 @@ class GenericSpec(GenericSpecFunctions):
     # Molecule Plugin factory support
     BASE_PLUGIN_API_VERSION = 0
 
+    @staticmethod
+    def require_super_user():
+        """
+        Determine whether super user access is required in order to execute
+        the given GenericSpec subclass. Default: True. Please override if
+        you allow unprivileged user execution.
+        """
+        return True
+
     @staticmethod
     def execution_strategy():
         """

molecule/utils.py

@@ -33,6 +33,12 @@ def get_year():
     """
     return time.strftime("%Y")
 
+def is_super_user():
+    """
+    Return True if current process has uid = 0.
+    """
+    return os.getuid() == 0
+
 def valid_exec_check(path):
     """
     Determine whethern give path is valid executable (by running it).