Issue 221 wfs3 Probe: OpenAPI spec validator for /api endpoint (#253)

* #221 add OpenAPI Validator Probe for WFS3

* #221 refine OpenAPI Validator Probe for WFS3

GeoHealthCheck/plugins/probe/wfs3.py

@@ -1,5 +1,6 @@
 import requests
 from owslib.wfs import WebFeatureService
+from openapi_spec_validator import openapi_v3_spec_validator
 
 from GeoHealthCheck.probe import Probe
 from GeoHealthCheck.result import Result
@@ -59,8 +60,8 @@ def perform_request(self):
                 val = api.get(attr, None)
                 if val is None:
                     msg = '/api: missing attr: %s' % attr
-                    result = self.add_result(
-                        result, False, msg, 'Test Collection')
+                    result = add_result(
+                        self, result, False, msg, 'Test Collection')
                     continue
 
             collections = wfs3.collections()
@@ -95,37 +96,37 @@ def perform_request(self):
                         if val is None:
                             msg = '%s: missing attr: %s' \
                                   % (coll_name, attr)
-                            result = self.add_result(
-                                result, False, msg, 'Test Collection')
+                            result = add_result(
+                                self, result, False, msg, 'Test Collection')
                             continue
                 except Exception as e:
                     msg = 'GetCollection %s: OWSLib err: %s ' \
                           % (str(e), coll_name)
-                    result = self.add_result(result,
-                                             False, msg, 'Test GetCollection')
+                    result = add_result(
+                        self, result, False, msg, 'Test GetCollection')
                     continue
 
                 try:
                     items = wfs3.collection_items(coll_name, limit=1)
                 except Exception as e:
                     msg = 'GetItems %s: OWSLib err: %s ' % (str(e), coll_name)
-                    result = self.add_result(result,
-                                             False, msg, 'Test GetItems')
+                    result = add_result(
+                        self, result, False, msg, 'Test GetItems')
                     continue
 
                 features = items.get('features', None)
                 if features is None:
                     msg = 'GetItems %s: No features attr' % coll_name
-                    result = self.add_result(result,
-                                             False, msg, 'Test GetItems')
+                    result = add_result(
+                        self, result, False, msg, 'Test GetItems')
                     continue
 
                 type = items.get('type', '')
                 if type != 'FeatureCollection':
                     msg = '%s:%s type not FeatureCollection: %s' \
                           % (coll_name, type, val)
-                    result = self.add_result(
-                        result, False, msg, 'Test GetItems')
+                    result = add_result(
+                        self, result, False, msg, 'Test GetItems')
                     continue
 
                 if len(items['features']) > 0:
@@ -136,8 +137,8 @@ def perform_request(self):
                     except Exception as e:
                         msg = 'GetItem %s: OWSLib err: %s' \
                               % (str(e), coll_name)
-                        result = self.add_result(result,
-                                                 False, msg, 'Test GetItem')
+                        result = add_result(
+                            self, result, False, msg, 'Test GetItem')
                         continue
 
                     for attr in \
@@ -146,15 +147,15 @@ def perform_request(self):
                         if val is None:
                             msg = '%s:%s missing attr: %s' \
                                   % (coll_name, str(fid), attr)
-                            result = self.add_result(
-                                result, False, msg, 'Test GetItem')
+                            result = add_result(
+                                self, result, False, msg, 'Test GetItem')
                             continue
 
                         if attr == 'type' and val != 'Feature':
                             msg = '%s:%s type not Feature: %s' \
                                   % (coll_name, str(fid), val)
-                            result = self.add_result(
-                                result, False, msg, 'Test GetItem')
+                            result = add_result(
+                                self, result, False, msg, 'Test GetItem')
                             continue
 
         except Exception as err:
@@ -166,13 +167,93 @@ def perform_request(self):
         # Add to overall Probe result
         self.result.add_result(result)
 
-    def add_result(self, result, val, msg, new_result_name):
-        result.set(val, msg)
+
+class WFS3OpenAPIValidator(Probe):
+    """
+    Probe for WFS3 OpenAPI Spec Validation (/api endpoint).
+    Uses https://pypi.org/project/openapi-spec-validator/.
+
+    """
+
+    NAME = 'WFS3 OpenAPI Validator'
+    DESCRIPTION = 'Validates WFS3 /api endpoint for OpenAPI compliance'
+    RESOURCE_TYPE = 'OGC:WFS3'
+
+    REQUEST_METHOD = 'GET'
+
+    """Param defs"""
+
+    def __init__(self):
+        Probe.__init__(self)
+
+    def perform_request(self):
+        """
+        Perform the validation.
+        Uses https://github.com/p1c2u/openapi-spec-validator on
+        the specfile (dict) returned from the OpenAPI endpoint.
+        """
+
+        # Step 1 basic sanity check
+        result = Result(True, 'OpenAPI Validation Test')
+        result.start()
+        api_doc = None
+        try:
+            wfs3 = WebFeatureService(self._resource.url, version='3.0')
+
+            # TODO: OWSLib 0.17.1 has no call to '/api yet.
+            # Build endpoint URL (may have f=json etc)
+            api_url = wfs3._build_url('api')
+
+            # Get OpenAPI spec from endpoint as dict once
+            api_doc = requests.get(api_url).json()
+
+            # Basic sanity check
+            for attr in ['components', 'paths', 'openapi']:
+                val = api_doc.get(attr, None)
+                if val is None:
+                    msg = '/api: missing attr: %s' % attr
+                    result.set(False, msg)
+                    break
+        except Exception as err:
+            result.set(False, str(err))
+
         result.stop()
         self.result.add_result(result)
-        result = Result(True, new_result_name)
+
+        # No use to proceed if OpenAPI basics not complied
+        if api_doc is None or result.success is False:
+            return
+
+        # ASSERTION: /api exists, next OpenAPI Validation
+
+        # Step 2 detailed OpenAPI Compliance test
+        result = Result(True, 'Validate OpenAPI Compliance')
         result.start()
-        return result
+        try:
+            # Call the openapi-spec-validator and iterate through errors
+            errors_iterator = openapi_v3_spec_validator.iter_errors(api_doc)
+            for error in errors_iterator:
+                # Add each validation error as separate Result object
+                result = add_result(
+                    self, result, False,
+                    str(error), 'OpenAPI Compliance Result')
+        except Exception as err:
+            result.set(False, 'OpenAPI Validation err: e=%s' % str(err))
+
+        result.stop()
+
+        # Add to overall Probe result
+        self.result.add_result(result)
+
+
+# Util to quickly add Results and open new one.
+def add_result(obj, result, val, msg, new_result_name):
+    result.set(val, msg)
+    result.stop()
+    obj.result.add_result(result)
+    result = Result(True, new_result_name)
+    result.start()
+    return result
 
 # class WFS3Caps(Probe):
 #     """Probe for OGC WFS3 API main endpoint url"""

requirements.txt

@@ -8,6 +8,7 @@ Flask-SQLAlchemy==2.1
 itsdangerous==1.1.0
 pyproj==1.9.6
 OWSLib==0.17.1
+openapi-spec-validator==0.2.7
 Sphinx==1.8.4
 sphinx-rtd-theme==0.4.3
 requests>=2.20.0