ntp: Add schema definition and passive schema validation.

cloud-config files are very flexible and permissive.
This adds a jsonsschema definition to the cc_ntp module and validation
functions in cloudinit/config/schema which will log warnings about
invalid configuration values in the ntp section.

A cmdline tools/cloudconfig-schema is added which can be used in our dev
environments to quickly attempt to exercise the ntp schema.
It is also exposed as a main in cloudinit.config.schema.
(python3 -m cloudinit.config.schema)

LP: #1692916

1 files changed, 35 insertions, 0 deletions

diff --git a/tools/cloudconfig-schema b/tools/cloudconfig-schema
new file mode 100755
index 00000000..32f0d61e
--- /dev/null
+++ b/tools/cloudconfig-schema
@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+# This file is part of cloud-init. See LICENSE file for license information.
+
+"""cloudconfig-schema
+
+Validate existing files against cloud-config schema or provide supported schema
+documentation.
+"""
+
+import os
+import sys
+
+
+def call_entry_point(name):
+    (istr, dot, ent) = name.rpartition('.')
+    try:
+        __import__(istr)
+    except ImportError:
+        # if that import failed, check dirname(__file__/..)
+        # to support ./bin/program with modules in .
+        _tdir = os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))
+        sys.path.insert(0, _tdir)
+        try:
+            __import__(istr)
+        except ImportError as e:
+            sys.stderr.write("Unable to find %s: %s\n" % (name, e))
+            sys.exit(2)
+
+    sys.exit(getattr(sys.modules[istr], ent)())
+
+
+if __name__ == '__main__':
+    call_entry_point("cloudinit.config.schema.main")
+
+# vi: ts=4 expandtab syntax=python