Drop mypy excluded files (#1454)

- Add types to let mypy pass.
- Add mypy flags:
  - detect unused ignores
  - redundant casts
- Drop support of `ConfigParser` in Python 2
- Harden DataSourceLXD.network_config
- Convert old-style commented types to proper types.

1 files changed, 14 insertions, 7 deletions

diff --git a/cloudinit/templater.py b/cloudinit/templater.py
index 298eaf6b..4d712829 100644
--- a/cloudinit/templater.py
+++ b/cloudinit/templater.py
@@ -10,31 +10,38 @@
 #
 # This file is part of cloud-init. See LICENSE file for license information.
 
+# noqa: E402
+
 import collections
 import re
 import sys
+from typing import Type
+
+from cloudinit import log as logging
+from cloudinit import type_utils as tu
+from cloudinit import util
+from cloudinit.atomic_helper import write_file
 
+JUndefined: Type
 try:
-    from jinja2 import DebugUndefined as JUndefined
+    from jinja2 import DebugUndefined as _DebugUndefined
     from jinja2 import Template as JTemplate
 
     JINJA_AVAILABLE = True
+    JUndefined = _DebugUndefined
 except (ImportError, AttributeError):
     JINJA_AVAILABLE = False
     JUndefined = object
 
-from cloudinit import log as logging
-from cloudinit import type_utils as tu
-from cloudinit import util
-from cloudinit.atomic_helper import write_file
-
 LOG = logging.getLogger(__name__)
 TYPE_MATCHER = re.compile(r"##\s*template:(.*)", re.I)
 BASIC_MATCHER = re.compile(r"\$\{([A-Za-z0-9_.]+)\}|\$([A-Za-z0-9_.]+)")
 MISSING_JINJA_PREFIX = "CI_MISSING_JINJA_VAR/"
 
 
-class UndefinedJinjaVariable(JUndefined):
+# Mypy, and the PEP 484 ecosystem in general, does not support creating
+# classes with dynamic base types: https://stackoverflow.com/a/59636248
+class UndefinedJinjaVariable(JUndefined):  # type: ignore
     """Class used to represent any undefined jinja template variable."""
 
     def __str__(self):