feat: lookup for configuration in parent directory (#305)

If salt-lint cannot find a configuration file in the current directory it attempts to locate it in a parent directory. However salt-lint does not try to load configuration that is outside the git repository.

---------

Signed-off-by: Roald Nefs <info@roaldnefs.com>
Co-authored-by: Roald Nefs <info@roaldnefs.com>

CHANGELOG.md

@@ -6,6 +6,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ## [Unreleased]
 ### Added
 - Add Python 3.12 support ([#315](https://github.com/warpnet/salt-lint/pull/315)).
+- Lookup configuration file in parent directory ([#305](https://github.com/warpnet/salt-lint/pull/305)).
 
 ### Fixed
 - Ignore false positive result in rule 210 ([#303](https://github.com/warpnet/salt-lint/pull/303)).

docs/index.md

@@ -136,6 +136,8 @@ jobs:
 
 Salt-lint supports local configuration via a `.salt-lint` configuration file. Salt-lint checks the working directory for the presence of this file and applies any configuration found there. The configuration file location can also be overridden via the `-c path/to/file` CLI flag.
 
+If salt-lint cannot find a configuration file in the current directory it attempts to locate it in a parent directory. However salt-lint does not try to load configuration that is outside the git repository.
+
 If a value is provided on both the command line and via a configuration file, the values will be merged (if a list like **exclude_paths**), or the **True** value will be preferred, in the case of something like **quiet**.
 
 The following values are supported, and function identically to their CLI counterparts:

saltlint/config.py

@@ -20,13 +20,15 @@ class Configuration(object):
 
     def __init__(self, options={}):
         self._options = options
-        # Configuration file to use, defaults to ".salt-lint".
         config = options.get('c')
-        file = config if config is not None else '.salt-lint'
 
-        # Read the file contents
-        if os.path.exists(file):
-            with open(file, 'r', encoding="UTF-8") as f:
+        # Configuration file is not set, defaults to ".salt-lint".
+        if config is None:
+            config = get_config_path()
+
+        # Read the configuration file contents if it exists.
+        if config and os.path.exists(config):
+            with open(config, 'r', encoding="UTF-8") as f:
                 content = f.read()
         else:
             content = None
@@ -130,3 +132,19 @@ def is_file_ignored(self, filepath, rule):
         if rule not in self.rules or 'ignore' not in self.rules[rule]:
             return False
         return self.rules[rule]['ignore'].match_file(filepath)
+
+
+def get_config_path():
+    """Return local configuration file."""
+    dirname = basename = os.getcwd()
+    while basename:
+        filename = os.path.abspath(os.path.join(dirname, ".salt-lint"))
+        if os.path.exists(filename):
+            return filename
+        if os.path.exists(os.path.abspath(os.path.join(dirname, ".git"))):
+            # Avoid looking outside .git folders as we do not want end-up
+            # picking config files from upper level projects if current
+            # project has no config.
+            return None
+        (dirname, basename) = os.path.split(dirname)
+    return None