Add: IsEmptyString error class

3 files changed, 13 insertions, 0 deletions

diff --git a/vmdb/__init__.py b/vmdb/__init__.py
index 63cf1b7..d494e0a 100644
--- a/vmdb/__init__.py
+++ b/vmdb/__init__.py
@@ -19,6 +19,7 @@
 from .version import __version__, __version_info__
 from .state import State
 from .step_list import (
+    IsEmptyString,
     StepRunnerList,
     StepRunnerInterface,
     NoMatchingRunner,
diff --git a/vmdb/plugins/luks_plugin.py b/vmdb/plugins/luks_plugin.py
index 9d48d99..c5e1bef 100644
--- a/vmdb/plugins/luks_plugin.py
+++ b/vmdb/plugins/luks_plugin.py
@@ -41,6 +41,11 @@ class CryptsetupStepRunner(vmdb.StepRunnerInterface):
         underlying = step['cryptsetup']
         crypt_name = step['tag']
 
+        if not isinstance(underlying, str):
+            raise vmdb.NotString('cryptsetup', underlying)
+        if not isinstance(crypt_name, str):
+            raise vmdb.NotString('cryptsetup: tag', crypt_name)
+
         state.tmp_key_file = None
         key_file = step.get('key-file')
         key_cmd = step.get('key-cmd')
diff --git a/vmdb/step_list.py b/vmdb/step_list.py
index 20e3ec6..468cf35 100644
--- a/vmdb/step_list.py
+++ b/vmdb/step_list.py
@@ -95,3 +95,10 @@ class NotString(StepError):  # pragma: no cover
     def __init__(self, name, actual):
         msg = '%s: value must be string, got %r' % (name, actual)
         super().__init__(msg)
+
+
+class IsEmptyString(StepError):  # pragma: no cover
+
+    def __init__(self, name, actual):
+        msg = '%s: value must not be an empty string, got %r' % (name, actual)
+        super().__init__(msg)