configuration overwrites with default values (#613)

* use last non default value

instead of using the last falsy value which asumes, that
all attributes have a falsy default we return the last non
default value instead.

* update changelog

CHANGELOG.md

@@ -9,11 +9,14 @@ This release limits the maximum python version to `3.12.3` because of the issue
 ### Breaking
 ### Features
 ### Improvements
+
 * a result object was added which is returned by every processor
   * includes generated extra_data, warnings and errors
 
 ### Bugfix
 
+* fixes a bug where it could happen that a config value could be overwritten by a default in a later configuration in a multi source config scenario
+
 ## 12.0.0
 
 ### Breaking

logprep/util/configuration.py

@@ -712,7 +712,7 @@ def _set_attributes_from_configs(self) -> None:
             setattr(
                 self,
                 attribute.name,
-                self._get_last_non_falsy_value(self._configs, attribute.name),
+                self._get_last_non_default_value(self._configs, attribute.name),
             )
         versions = (config.version for config in self._configs if config.version)
         self.version = ", ".join(versions)
@@ -790,11 +790,18 @@ def _resolve_directories(rule_sources: list) -> list:
         return resolved_sources
 
     @staticmethod
-    def _get_last_non_falsy_value(configs: list["Configuration"], attribute: str) -> Any:
+    def _get_last_non_default_value(configs: list["Configuration"], attribute: str) -> Any:
         if configs:
+            config = configs[0]
+            attrs_attribute = [attr for attr in config.__attrs_attrs__ if attr.name == attribute][0]
+            default_for_attribute = (
+                attrs_attribute.default.factory()
+                if hasattr(attrs_attribute.default, "factory")
+                else attrs_attribute.default
+            )
             values = [getattr(config, attribute) for config in configs]
             for value in reversed(values):
-                if value:
+                if value != default_for_attribute:
                     return value
             return values[-1]
         return getattr(Configuration(), attribute)

tests/unit/util/test_configuration.py

@@ -1215,6 +1215,56 @@ def test_verify_credentials_file_raises_for_unexpected_key(self, config_path, tm
             ):
                 _ = Configuration.from_sources([str(config_path)])
 
+    def test_no_config_parameter_is_overwritten_with_a_default(self, tmp_path):
+        prometheus_multiproc_dir: Path = tmp_path / "prometheus_multiproc_dir"
+        prometheus_multiproc_dir.mkdir()
+        exporter_config = tmp_path / "exporter-config"
+        exporter_config.write_text(
+            """
+metrics:
+  enabled: true
+  port: 8000
+"""
+        )
+        input_config = tmp_path / "input-config"
+        input_config.write_text(
+            """
+input:
+  stdin:
+    type: file_input
+    logfile_path: /proc/1/fdinfo/0
+    start: end
+    watch_file: true
+    interval: 1
+"""
+        )
+
+        output_config = tmp_path / "output-config"
+        output_config.write_text(
+            """
+output:
+  console:
+    type: console_output
+"""
+        )
+        with mock.patch.dict(
+            "os.environ", {"PROMETHEUS_MULTIPROC_DIR": str(prometheus_multiproc_dir)}
+        ):
+            config1 = Configuration.from_sources(
+                [str(input_config), str(output_config), str(exporter_config)]
+            )
+            assert config1.metrics.enabled
+
+            config1 = Configuration.from_sources(
+                [str(exporter_config), str(input_config), str(output_config)]
+            )
+            assert config1.metrics.enabled
+
+            config1 = Configuration.from_sources(
+                [str(input_config), str(exporter_config), str(output_config)]
+            )
+            assert config1.metrics.enabled
+
     def test_verify_calls_processor_setup(self, config_path):
         config = Configuration.from_sources([str(config_path)])
         with mock.patch("logprep.abc.processor.Processor.setup") as mocked_setup: