Add schema to validate query parameter

Added schema to validate following query parameters:-

1. filter
2. all_fields
3. exclude_fields
4. fields
5. exclude_default

Business rules are defined in ETSI GS NFV-SOL 013 V2.6.1 (2019-03),
section 5.2 and 5.3.

Change-Id: I01cf08f46ffd69d10f5afde430c42c4bc211bd25
Implements: bp/enhance-vnf-package-support-part1

tacker/api/schemas/vnf_packages.py

@@ -67,3 +67,15 @@ patch = {
               {'required': ['userDefinedData']}],
     'additionalProperties': False
 }
+
+query_params_v1 = {
+    'type': 'object',
+    "properties": {
+        'filter': {'type': 'string', 'minLength': 1},
+        'exclude_fields': {'type': 'string', 'minLength': 1},
+        'fields': {'type': 'string', 'minLength': 1},
+        'all_fields': {'format': 'all_fields'},
+        'exclude_default': {'format': 'exclude_default'},
+    },
+    'additionalProperties': False,
+}

tacker/api/validation/__init__.py

@@ -22,6 +22,7 @@ import functools
 import webob
 
 from tacker.api.validation import validators
+from tacker.common import exceptions
 
 
 def schema(request_body_schema):
@@ -49,3 +50,42 @@ def schema(request_body_schema):
         return wrapper
 
     return add_validator
+
+
+def query_schema(query_params_schema):
+    """Register a schema to validate request query parameters.
+
+    Registered schema will be used for validating request query params just
+    before API method executing.
+
+    :param query_params_schema: A dict, the JSON-Schema for validating the
+                                query parameters.
+    """
+
+    def add_validator(func):
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            # NOTE(tpatil): The second argument of the method
+            # calling this method should always be 'request'.
+            if 'request' in kwargs:
+                req = kwargs['request']
+            else:
+                req = args[1]
+
+            try:
+                req.GET.dict_of_lists()
+            except UnicodeDecodeError:
+                msg = _('Query string is not UTF-8 encoded')
+                raise exceptions.ValidationError(msg)
+
+            query_opts = {}
+            query_opts.update(req.GET)
+            schema_validator = validators._SchemaValidator(
+                query_params_schema)
+            schema_validator.validate(query_opts)
+
+            return func(*args, **kwargs)
+
+        return wrapper
+
+    return add_validator

tacker/api/validation/validators.py

@@ -55,6 +55,28 @@ def validate_mac_address_or_none(instance):
     return True
 
 
+def _validate_query_parameter_without_value(parameter_name, instance):
+    """The query parameter is a flag without a value."""
+    if not (isinstance(instance, six.text_type) and len(instance)):
+        return True
+
+    msg = _("The parameter '%s' is a flag. It shouldn't contain any value.")
+    raise webob.exc.HTTPBadRequest(explanation=msg % parameter_name)
+
+
+@jsonschema.FormatChecker.cls_checks('all_fields',
+        webob.exc.HTTPBadRequest)
+def _validate_all_fields_query_parameter(instance):
+    return _validate_query_parameter_without_value('all_fields', instance)
+
+
+@jsonschema.FormatChecker.cls_checks('exclude_default',
+        webob.exc.HTTPBadRequest)
+def _validate_exclude_default_query_parameter(instance):
+    return _validate_query_parameter_without_value('exclude_default',
+            instance)
+
+
 class FormatChecker(jsonschema.FormatChecker):
     """A FormatChecker can output the message from cause exception
 

tacker/api/vnfpkgm/v1/controller.py

@@ -108,7 +108,8 @@ class VnfPkgmController(wsgi.Controller):
         return self._view_builder.show(request, vnf_package)
 
     @wsgi.response(http_client.OK)
-    @wsgi.expected_errors((http_client.FORBIDDEN))
+    @wsgi.expected_errors((http_client.BAD_REQUEST, http_client.FORBIDDEN))
+    @validation.query_schema(vnf_packages.query_params_v1)
     def index(self, request):
         context = request.environ['tacker.context']
         context.can(vnf_package_policies.VNFPKGM % 'index')