saltclass: Reference classes with globs

Allow the list of classes in saltclass external pillar/master_tops
to include shell-style globs.

salt/utils/saltclass.py

@@ -2,6 +2,7 @@
 # Import Python libs
 from __future__ import absolute_import, print_function, unicode_literals
 
+import glob
 import logging
 import os
 import re
@@ -43,13 +44,7 @@ def get_class(_class, salt_data):
     l_files = []
     saltclass_path = salt_data["path"]
 
-    straight = os.path.join(saltclass_path, "classes", "{0}.yml".format(_class))
-    sub_straight = os.path.join(
-        saltclass_path, "classes", "{0}.yml".format(_class.replace(".", os.sep))
-    )
-    sub_init = os.path.join(
-        saltclass_path, "classes", _class.replace(".", os.sep), "init.yml"
-    )
+    straight, sub_init, sub_straight = get_class_paths(_class, saltclass_path)
 
     for root, dirs, files in salt.utils.path.os_walk(
         os.path.join(saltclass_path, "classes"), followlinks=True
@@ -70,6 +65,51 @@ def get_class(_class, salt_data):
     return {}
 
 
+def get_class_paths(_class, saltclass_path):
+    """
+    Converts the dotted notation of a saltclass class to its possible file counterparts.
+
+    :param str _class: Dotted notation of the class
+    :param str saltclass_path: Root to saltclass storage
+    :return: 3-tuple of possible file counterparts
+    :rtype: tuple(str)
+    """
+    straight = os.path.join(saltclass_path, "classes", "{0}.yml".format(_class))
+    sub_straight = os.path.join(
+        saltclass_path, "classes", "{0}.yml".format(_class.replace(".", os.sep))
+    )
+    sub_init = os.path.join(
+        saltclass_path, "classes", _class.replace(".", os.sep), "init.yml"
+    )
+    return straight, sub_init, sub_straight
+
+
+def get_class_from_file(_file, saltclass_path):
+    """
+    Converts the absolute path to a saltclass file back to the dotted notation.
+
+    .. code-block:: python
+
+       print(get_class_from_file('/srv/saltclass/classes/services/nginx/init.yml', '/srv/saltclass'))
+       # services.nginx
+
+    :param str _file: Absolute path to file
+    :param str saltclass_path: Root to saltclass storage
+    :return: class name in dotted notation
+    :rtype: str
+    """
+    # remove classes path prefix
+    _file = _file[len(os.path.join(saltclass_path, "classes")) + len(os.sep) :]
+    # remove .yml extension
+    _file = _file[:-4]
+    # revert to dotted notation
+    _file = _file.replace(os.sep, ".")
+    # remove tailing init
+    if _file.endswith(".init"):
+        _file = _file[:-5]
+    return _file
+
+
 # Return environment
 def get_env_from_dict(exp_dict_list):
     environment = ""
@@ -189,6 +229,61 @@ def expand_variables(a, b, expanded, path=None):
     return b
 
 
+def match_class_glob(_class, saltclass_path):
+    """
+    Takes a class name possibly including `*` or `?` wildcards (or any other wildcards supportet by `glob.glob`) and
+    returns a list of expanded class names without wildcards.
+
+    .. code-block:: python
+
+       classes = match_class_glob('services.*', '/srv/saltclass')
+       print(classes)
+       # services.mariadb
+       # services.nginx...
+
+
+    :param str _class: dotted class name, globbing allowed.
+    :param str saltclass_path: path to the saltclass root directory.
+
+    :return: The list of expanded class matches.
+    :rtype: list(str)
+    """
+    straight, sub_init, sub_straight = get_class_paths(_class, saltclass_path)
+    classes = []
+    matches = []
+    matches.extend(glob.glob(straight))
+    matches.extend(glob.glob(sub_straight))
+    matches.extend(glob.glob(sub_init))
+    if len(matches) == 0:
+        log.warning("%s: Class globbing did not yield any results", _class)
+    for match in matches:
+        classes.append(get_class_from_file(match, saltclass_path))
+    return classes
+
+
+def expand_classes_glob(classes, salt_data):
+    """
+    Expand the list of `classes` to no longer include any globbing.
+
+    :param iterable(str) classes: Iterable of classes
+    :param dict salt_data: configuration data
+    :return: Expanded list of classes with resolved globbing
+    :rtype: list(str)
+    """
+    all_classes = []
+    expanded_classes = []
+    saltclass_path = salt_data["path"]
+
+    for _class in classes:
+        all_classes.extend(match_class_glob(_class, saltclass_path))
+
+    for _class in all_classes:
+        if _class not in expanded_classes:
+            expanded_classes.append(_class)
+
+    return expanded_classes
+
+
 def expand_classes_in_order(
     minion_dict, salt_data, seen_classes, expanded_classes, classes_to_expand
 ):
@@ -196,6 +291,8 @@ def expand_classes_in_order(
     if not classes_to_expand and "classes" in minion_dict:
         classes_to_expand = minion_dict["classes"]
 
+    classes_to_expand = expand_classes_glob(classes_to_expand, salt_data)
+
     # Now loop on list to recursively expand them
     for klass in classes_to_expand:
         if klass not in seen_classes:

tests/integration/files/saltclass/examples/nodes/fake_id.yml

@@ -1,6 +1,6 @@
 environment: base
 
 classes:
-{% for class in ['default', 'roles.app'] %}
+{% for class in ['default', 'roles.*', 'empty.*'] %}
   - {{ class }}
 {% endfor %}

tests/unit/pillar/test_saltclass.py

@@ -83,5 +83,12 @@ class SaltclassPillarTestCaseListExpansion(TestCase, LoaderModuleMockMixin):
         self.assertListEqual(parsed_ret, expected_ret)
 
     def test_succeeds(self):
-        ret = [{"a": "192.168.10.10"}, "192.168.10.20"]
+        ret = [
+            "default.users",
+            "default.motd",
+            "default.empty",
+            "default",
+            "roles.app",
+            "roles.nginx",
+        ]
         self._runner(ret)