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, 4 insertions, 2 deletions

diff --git a/tests/unittests/config/test_cc_write_files_deferred.py b/tests/unittests/config/test_cc_write_files_deferred.py
index 3faac1bf..17203233 100644
--- a/tests/unittests/config/test_cc_write_files_deferred.py
+++ b/tests/unittests/config/test_cc_write_files_deferred.py
@@ -43,9 +43,11 @@ class TestWriteFilesDeferredSchema(CiTestCase):
 
         cc = self.tmp_cloud("ubuntu")
         handle("cc_write_files_deferred", valid_config, cc, LOG, [])
-        self.assertNotIn("Invalid config:", self.logs.getvalue())
+        self.assertNotIn(
+            "Invalid cloud-config provided:", self.logs.getvalue()
+        )
         handle("cc_write_files_deferred", invalid_config, cc, LOG, [])
-        self.assertIn("Invalid config:", self.logs.getvalue())
+        self.assertIn("Invalid cloud-config provided:", self.logs.getvalue())
         self.assertIn(
             "defer: 'no' is not of type 'boolean'", self.logs.getvalue()
         )