merge_configs: Add lstrip_blocks

Closes-Bug: #2164718

Change-Id: If5b7f30d2467b61c3578d09992faf446b5d25f4e
Signed-off-by: Michal Nasiadka <mnasiadka@gmail.com>
(cherry picked from commit 0f4da209da6fa39739ffc7b7fb1a69dc967734b7)

1 files changed, 32 insertions, 0 deletions

diff --git a/tests/test_merge_yaml.py b/tests/test_merge_yaml.py
index d6b74ae77..35de91d2c 100644
--- a/tests/test_merge_yaml.py
+++ b/tests/test_merge_yaml.py
@@ -15,8 +15,11 @@
 
 from importlib.machinery import SourceFileLoader
 import os
+import tempfile
 
 from ansible.errors import AnsibleModuleError
+from ansible.parsing.dataloader import DataLoader
+from ansible.template import Templar
 from oslotest import base
 
 PROJECT_DIR = os.path.abspath(os.path.join(os. path.dirname(__file__), '../'))
@@ -174,3 +177,32 @@ class MergeYamlConfigTest(base.BaseTestCase):
         with self.assertRaisesRegex(AnsibleModuleError, "Failure merging key"):
             merge_yaml.Utils.update_nested_conf(
                 initial_conf, extension, extend_lists=True)
+
+    def test_read_config_lstrip_blocks(self):
+        # An indented Jinja2 block tag on its own line must not leak its
+        # leading whitespace into the following line, or the resulting
+        # YAML indentation becomes inconsistent with its siblings.
+        content = (
+            "foo:\n"
+            "  bar: baz\n"
+            "  {% if true %}\n"
+            "  extra: value\n"
+            "  {% endif %}\n"
+            "  qux: quux\n"
+        )
+        with tempfile.TemporaryDirectory() as tmpdir:
+            source = os.path.join(tmpdir, 'source.yml')
+            with open(source, 'w') as f:
+                f.write(content)
+
+            loader = DataLoader()
+            loader.set_basedir(tmpdir)
+            action = object.__new__(merge_yaml.ActionModule)
+            action._loader = loader
+            action._templar = Templar(loader=loader)
+
+            result = action.read_config(source)
+
+        self.assertEqual(
+            {'foo': {'bar': 'baz', 'extra': 'value', 'qux': 'quux'}},
+            result)