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, 7 insertions, 0 deletions

diff --git a/cloudinit/cmd/main.py b/cloudinit/cmd/main.py
index e67edbc3..c9be41b3 100644
--- a/cloudinit/cmd/main.py
+++ b/cloudinit/cmd/main.py
@@ -22,6 +22,7 @@ from cloudinit import patcher
 
 patcher.patch_logging()
 
+from cloudinit.config.schema import validate_cloudconfig_schema
 from cloudinit import log as logging
 from cloudinit import netinfo
 from cloudinit import signal_handler
@@ -474,6 +475,12 @@ def main_init(name, args):
         util.logexc(LOG, "Consuming user data failed!")
         return (init.datasource, ["Consuming user data failed!"])
 
+    # Validate user-data adheres to schema definition
+    if os.path.exists(init.paths.get_ipath_cur("userdata_raw")):
+        validate_cloudconfig_schema(config=init.cfg, strict=False)
+    else:
+        LOG.debug("Skipping user-data validation. No user-data found.")
+
     apply_reporting_cfg(init.cfg)
 
     # Stage 8 - re-read and apply relevant cloud-config to include user-data