Single JSON schema validation in early boot (#1175)

Package a single JSON schema file for user-data validation at
cloudinit/config/cloud-init-schema.json.

Perform validate_cloudconfig_schema call to just after the
user-data is consumed. This will allow single validation of all
user-data against the full schema instead of
repetitive validatation calls against each cloud-config module
(cloudinit.config.cc_*) sub-schemas.

This branch defines the simple apt_pipelining schema and
migrates existing cc_apk_configure into cloud-init-schema.json.

The expectation will be additional branches to migrate from legacy
"schema" attributes inside each cloud-config module toward unique
cc_<module_name> definitions in the global shema file under "$defs"
of cloud-init-schema-X.Y..json.

Before legacy sub-schema definitions are migrated the following
funcs grew support to read sub-schemas from both static
cloud-init-schema.json and the individual cloud-config module
"schema" attributes:

- get_schema: source base schema file from cloud-init-schema.json
  and supplement with all legacy cloud-config module "schema" defs
- get_meta_doc: optional schema param so cloud-config modules
  no longer provide the own local sub-schemas
- _get_property_doc: render only documentation of sub-schema based
  on meta['id'] provided
- validate_cloudconfig_schema: allow optional schema param


Additionally, fix two minor bugs in _schemapath_for_cloudconfig:
- `cloud-init devel schema --annotate` which results in a Traceback
  if two keys at the same indent level have invalid types.
- exit early on empty cloud-config to avoid a Traceback on the CLI

1 files changed, 43 insertions, 6 deletions

diff --git a/tests/unittests/config/test_cc_apt_pipelining.py b/tests/unittests/config/test_cc_apt_pipelining.py
index b4497156..0f72d32b 100644
--- a/tests/unittests/config/test_cc_apt_pipelining.py
+++ b/tests/unittests/config/test_cc_apt_pipelining.py
@@ -2,16 +2,23 @@
 
 """Tests cc_apt_pipelining handler"""
 
+import pytest
+
 import cloudinit.config.cc_apt_pipelining as cc_apt_pipelining
-from tests.unittests.helpers import CiTestCase, mock
+from cloudinit.config.schema import (
+    SchemaValidationError,
+    get_schema,
+    validate_cloudconfig_schema,
+)
+from tests.unittests.helpers import mock, skipUnlessJsonSchema
 
 
-class TestAptPipelining(CiTestCase):
+class TestAptPipelining:
     @mock.patch("cloudinit.config.cc_apt_pipelining.util.write_file")
     def test_not_disabled_by_default(self, m_write_file):
         """ensure that default behaviour is to not disable pipelining"""
         cc_apt_pipelining.handle("foo", {}, None, mock.MagicMock(), None)
-        self.assertEqual(0, m_write_file.call_count)
+        assert 0 == m_write_file.call_count
 
     @mock.patch("cloudinit.config.cc_apt_pipelining.util.write_file")
     def test_false_disables_pipelining(self, m_write_file):
@@ -19,10 +26,40 @@ class TestAptPipelining(CiTestCase):
         cc_apt_pipelining.handle(
             "foo", {"apt_pipelining": "false"}, None, mock.MagicMock(), None
         )
-        self.assertEqual(1, m_write_file.call_count)
+        assert 1 == m_write_file.call_count
         args, _ = m_write_file.call_args
-        self.assertEqual(cc_apt_pipelining.DEFAULT_FILE, args[0])
-        self.assertIn('Pipeline-Depth "0"', args[1])
+        assert cc_apt_pipelining.DEFAULT_FILE == args[0]
+        assert 'Pipeline-Depth "0"' in args[1]
+
+    @pytest.mark.parametrize(
+        "config, error_msg",
+        (
+            # Valid schemas
+            ({}, None),
+            ({"apt_pipelining": 1}, None),
+            ({"apt_pipelining": True}, None),
+            ({"apt_pipelining": False}, None),
+            ({"apt_pipelining": "none"}, None),
+            ({"apt_pipelining": "unchanged"}, None),
+            ({"apt_pipelining": "os"}, None),
+            # Invalid schemas
+            (
+                {"apt_pipelining": "bogus"},
+                "Cloud config schema errors: apt_pipelining: 'bogus' is not"
+                " valid under any of the given schema",
+            ),
+        ),
+    )
+    @skipUnlessJsonSchema()
+    def test_schema_validation(self, config, error_msg):
+        """Assert expected schema validation and error messages."""
+        # New-style schema $defs exist in config/cloud-init-schema*.json
+        schema = get_schema()
+        if error_msg is None:
+            validate_cloudconfig_schema(config, schema, strict=True)
+        else:
+            with pytest.raises(SchemaValidationError, match=error_msg):
+                validate_cloudconfig_schema(config, schema, strict=True)
 
 
 # vi: ts=4 expandtab