Separate custom jsonschema for action parameters

Keep the standard draft 4 schema separate from the customized schema for
action parameters. The standard draft is used by the API models and
should not mix with the customization.

Author: m4dcoder

st2common/st2common/models/api/action.py

@@ -55,7 +55,7 @@ class RunnerTypeAPI(BaseAPI):
                 "description": "Input parameters for the action runner.",
                 "type": "object",
                 "patternProperties": {
-                    "^\w+$": util_schema.get_draft_schema()
+                    "^\w+$": util_schema.get_action_params_schema()
                 }
             },
             "required_parameters": {
@@ -139,7 +139,7 @@ class ActionAPI(BaseAPI):
                 "description": "Input parameters for the action.",
                 "type": "object",
                 "patternProperties": {
-                    "^\w+$": util_schema.get_draft_schema()
+                    "^\w+$": util_schema.get_action_params_schema()
                 }
             },
             "required_parameters": {

st2common/st2common/util/jsonify.py

@@ -8,9 +8,14 @@
 
 
 __all__ = [
-    'json_encode',
+    'json_encode'
 ]
 
 
 def json_encode(obj, indent=4):
     return json.dumps(obj, cls=GenericJSON, indent=indent)
+
+
+def load_file(path):
+    with open(path, 'r') as fd:
+        return json.load(fd)

st2common/st2common/util/schema.py

@@ -0,0 +1,82 @@
+import os
+
+import six
+import jsonschema
+from oslo.config import cfg
+
+from st2common.util import jsonify
+
+
+# https://github.com/json-schema/json-schema/blob/master/draft-04/schema
+# The source material is licensed under the AFL or BSD license.
+PATH = os.path.join(os.path.dirname(os.path.realpath(__file__)))
+SCHEMA_DRAFT4 = jsonify.load_file('%s/draft4.json' % PATH)
+SCHEMA_ACTION_PARAMS = jsonify.load_file('%s/action_params.json' % PATH)
+
+SCHEMA_ANY_TYPE = {
+    "anyOf": [
+        {"type": "array"},
+        {"type": "boolean"},
+        {"type": "integer"},
+        {"type": "number"},
+        {"type": "object"},
+        {"type": "string"}
+    ]
+}
+
+
+def get_standard_draft_schema():
+    return SCHEMA_DRAFT4
+
+
+def get_action_params_schema():
+    return SCHEMA_ACTION_PARAMS
+
+
+def extend_with_default(validator_class):
+    validate_properties = validator_class.VALIDATORS["properties"]
+
+    def set_defaults(validator, properties, instance, schema):
+        for error in validate_properties(
+            validator, properties, instance, schema,
+        ):
+            yield error
+
+        for property, subschema in six.iteritems(properties):
+            if "default" in subschema:
+                instance.setdefault(property, subschema["default"])
+
+    return jsonschema.validators.extend(
+        validator_class, {"properties": set_defaults},
+    )
+
+
+def get_validator(assign_property_default=False):
+    validator = jsonschema.Draft4Validator
+    return extend_with_default(validator) if assign_property_default else validator
+
+
+def get_parameter_schema(model):
+    # Dynamically construct JSON schema from the parameters metadata.
+    schema = {"$schema": cfg.CONF.schema.draft}
+    from st2common.util.action_db import get_runnertype_by_name
+    runner_type = get_runnertype_by_name(model.runner_type['name'])
+    # Any 'required' runner parameter which is provided in the action is no longer
+    # considered 'required' by the runner. The action could choose to keep it
+    # 'required' but will have to explicitly call it out.
+    runner_required_parameters = [p for p in runner_type.required_parameters
+                                  if p not in model.parameters]
+    required = list(set(runner_required_parameters + model.required_parameters))
+    normalize = lambda x: {k: v if v else SCHEMA_ANY_TYPE for k, v in six.iteritems(x)}
+    properties = normalize(runner_type.runner_parameters)
+    properties.update(normalize(model.parameters))
+    if properties:
+        schema['title'] = model.name
+        if model.description:
+            schema['description'] = model.description
+        schema['type'] = 'object'
+        schema['properties'] = properties
+        if required:
+            schema['required'] = required
+        schema['additionalProperties'] = False
+    return schema