fix: make yaml output pass ansible-lint (#160)

* fix: add yaml boundary marker to header

Signed-off-by: gardar <[email protected]>

* fix: Increase indent of list items in yaml output

Signed-off-by: gardar <[email protected]>

* fix: make nice yaml formatter optional

Signed-off-by: gardar <[email protected]>

* fix: make nice yaml argument optional

Signed-off-by: gardar <[email protected]>

* fix: lint

Signed-off-by: gardar <[email protected]>

* fix: typos

Signed-off-by: gardar <[email protected]>

* Apply suggestions from code review

Co-authored-by: Felix Fontein <[email protected]>

* fix: alphabetical order

Signed-off-by: gardar <[email protected]>

---------

Signed-off-by: gardar <[email protected]>
Co-authored-by: Felix Fontein <[email protected]>

changelogs/config.yaml

@@ -37,3 +37,4 @@ output_formats:
   - rst
   - md
 add_plugin_period: false
+changelog_nice_yaml: false

changelogs/fragments/160-changelog-nice-yaml.yml

@@ -0,0 +1,9 @@
+---
+minor_changes:
+  - |
+    There is now an option ``changelog_nice_yaml`` to prepend the YAML document start
+    marker ``---`` to the header of the ``changelogs/changelog.yaml`` file, and to increases
+    indentation level on list items. This makes the file pass ansible-lint
+    (https://github.com/ansible-community/antsibull-changelog/issues/91,
+    https://github.com/ansible-community/antsibull-changelog/issues/152,
+    https://github.com/ansible-community/antsibull-changelog/pull/160).

docs/changelog-configuration.md

@@ -92,6 +92,17 @@ except when using the changelog generator for Ansible 2.9 or earlier.
 Note that support for `classic` is **DEPRECATED** and will be removed in
 a future release. The field will from then on be required.
 
+### `changelog_nice_yaml` (boolean)
+
+The default is `false`.
+
+When set to `true`, the `changelogs/changelog.yaml` file will be written with a slightly different
+YAML encoding that is compatible with ansible-lint's default rules.
+
+!!! note
+    The exact format used might be adjusted in the future if new releases of ansible-lint
+    adjust their yamllint configuration.
+
 ### `flatmap` (optional boolean)
 
 The default value is `null`.

src/antsibull_changelog/changes.py

@@ -156,7 +156,7 @@ def save(self) -> None:
         """
         self.sort()
         self.data["ancestor"] = self.ancestor
-        store_yaml(self.path, self.data)
+        store_yaml(self.path, self.data, self.config.changelog_nice_yaml)
 
     def add_release(
         self,

src/antsibull_changelog/config.py

@@ -379,6 +379,7 @@ class ChangelogConfig:
     sections: Mapping[str, str]
     output_formats: set[TextFormat]
     add_plugin_period: bool
+    changelog_nice_yaml: bool
 
     def __init__(
         self,
@@ -468,6 +469,8 @@ def __init__(
 
         self.add_plugin_period = self.config.get("add_plugin_period", False)
 
+        self.changelog_nice_yaml = self.config.get("changelog_nice_yaml", False)
+
         self._validate_config(ignore_is_other_project)
 
     def _validate_config(self, ignore_is_other_project: bool) -> None:
@@ -518,6 +521,7 @@ def store(self) -> None:  # noqa: C901
             "ignore_other_fragment_extensions": self.ignore_other_fragment_extensions,
             "sanitize_changelog": self.sanitize_changelog,
             "add_plugin_period": self.add_plugin_period,
+            "changelog_nice_yaml": self.changelog_nice_yaml,
         }
         if not self.is_collection:
             if self.use_semantic_versioning:
@@ -597,6 +601,7 @@ def default(
             "ignore_other_fragment_extensions": True,
             "sanitize_changelog": True,
             "add_plugin_period": True,
+            "changelog_nice_yaml": False,
         }
         if title is not None:
             config["title"] = title

src/antsibull_changelog/yaml.py

@@ -25,6 +25,15 @@
     from yaml import SafeLoader as _SafeLoader
 
 
+class _IndentedDumper(yaml.SafeDumper):
+    """
+    Extend YAML dumper to increase indent of list items.
+    """
+
+    def increase_indent(self, flow=False, indentless=False):
+        return super().increase_indent(flow, False)
+
+
 def load_yaml(path: str) -> Any:
     """
     Load and parse YAML file ``path``.
@@ -33,11 +42,15 @@ def load_yaml(path: str) -> Any:
         return yaml.load(stream, Loader=_SafeLoader)
 
 
-def store_yaml(path: str, content: Any) -> None:
+def store_yaml(path: str, content: Any, nice: bool = False) -> None:
     """
     Store ``content`` as YAML file under ``path``.
     """
     with open(path, "w", encoding="utf-8") as stream:
-        dumper = _SafeDumper
-        dumper.ignore_aliases = lambda *args: True
-        yaml.dump(content, stream, default_flow_style=False, Dumper=dumper)
+        yaml.dump(
+            content,
+            stream,
+            default_flow_style=False,
+            Dumper=_IndentedDumper if nice else _SafeDumper,
+            explicit_start=nice,
+        )