Request middleware conditionally require content-type

Change to the YAMLTranslator middleware to only require content-type
when the request should require it.  GET and DELETE should not, and
PUT and POST should only require it when there is a message body.

Change-Id: I8614ff077c4fc5b19b77e12a468e053c76733487

deckhand/control/middleware.py

@@ -118,20 +118,33 @@ class YAMLTranslator(HookableMiddlewareMixin, object):
     def process_request(self, req, resp):
         """Performs content type enforcement on behalf of REST verbs."""
         valid_content_types = ['application/x-yaml']
-        content_type = (req.content_type.split(';', 1)[0].strip()
+
+        # GET and DELETE should never carry a message body, and have
+        # no content type. Check for content-length or
+        # transfer-encoding to determine if a content-type header
+        # is required.
+        requires_content_type = (
+            req.method not in ['GET', 'DELETE'] and (
+                req.content_length is not None or
+                req.get_header('transfer-encoding') is not None
+            )
+        )
+
+        if requires_content_type:
+            content_type = (req.content_type.split(';', 1)[0].strip()
                         if req.content_type else '')
 
-        if not content_type:
-            raise falcon.HTTPMissingHeader('Content-Type')
-        elif content_type not in valid_content_types:
-            message = (
-                "Unexpected content type: {type}. Expected content types "
-                "are: {expected}."
-            ).format(
-                type=six.b(req.content_type).decode('utf-8'),
-                expected=valid_content_types
-            )
-            raise falcon.HTTPUnsupportedMediaType(description=message)
+            if not content_type:
+                raise falcon.HTTPMissingHeader('Content-Type')
+            elif content_type not in valid_content_types:
+                message = (
+                    "Unexpected content type: {type}. Expected content types "
+                    "are: {expected}."
+                ).format(
+                    type=six.b(req.content_type).decode('utf-8'),
+                    expected=valid_content_types
+                )
+                raise falcon.HTTPUnsupportedMediaType(description=message)
 
     def process_response(self, req, resp, resource):
         """Converts responses to ``application/x-yaml`` content type."""

deckhand/tests/unit/control/base.py

@@ -12,6 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import os
+import yaml
+
 from falcon import testing as falcon_testing
 
 from deckhand import service
@@ -31,3 +34,13 @@ class BaseControllerTest(test_base.DeckhandWithDBTestCase,
         # NOTE: allow_anonymous_access allows these unit tests to get around
         # Keystone authentication.
         self.useFixture(fixtures.ConfPatcher(allow_anonymous_access=True))
+
+    def _read_data(self, file_name):
+        # Reads data from a file in the resources directory
+        dir_path = os.path.dirname(os.path.realpath(__file__))
+        test_yaml_path = os.path.abspath(os.path.join(
+            dir_path, os.pardir, 'resources', file_name + '.yaml'))
+
+        with open(test_yaml_path, 'r') as yaml_file:
+            yaml_data = yaml_file.read()
+        self.data = yaml.safe_load(yaml_data)

deckhand/tests/unit/control/test_middleware.py

@@ -22,21 +22,85 @@ from deckhand.tests.unit.control import base as test_base
 class TestYAMLTranslator(test_base.BaseControllerTest):
 
     def test_request_with_correct_content_type(self):
+        rules = {'deckhand:create_cleartext_documents': '@'}
+        self.policy.set_rules(rules)
+        self._read_data('sample_document_simple')
+        resp = self.app.simulate_put(
+            '/api/v1.0/buckets/b1/documents',
+            headers={'Content-Type': 'application/x-yaml'},
+            body=yaml.safe_dump(self.data),
+        )
+        self.assertEqual(200, resp.status_code)
+
+    def test_request_empty_put_and_content_type(self):
+        rules = {'deckhand:create_cleartext_documents': '@'}
+        self.policy.set_rules(rules)
+        resp = self.app.simulate_put(
+            '/api/v1.0/buckets/b1/documents',
+            headers={'Content-Type': 'application/x-yaml'},
+        )
+        self.assertEqual(200, resp.status_code)
+
+    def test_request_empty_put_and_no_content_type(self):
+        rules = {'deckhand:create_cleartext_documents': '@'}
+        self.policy.set_rules(rules)
+        resp = self.app.simulate_put(
+            '/api/v1.0/buckets/b1/documents',
+        )
+        self.assertEqual(200, resp.status_code)
+
+    def test_request_zero_length_put_and_no_content_type(self):
+        rules = {'deckhand:create_cleartext_documents': '@'}
+        self.policy.set_rules(rules)
+        resp = self.app.simulate_put(
+            '/api/v1.0/buckets/b1/documents',
+            body='',
+        )
+        self.assertEqual(200, resp.status_code)
+
+    def test_request_zero_length_put_and_content_type(self):
+        rules = {'deckhand:create_cleartext_documents': '@'}
+        self.policy.set_rules(rules)
+        resp = self.app.simulate_put(
+            '/api/v1.0/buckets/b1/documents',
+            headers={'Content-Type': 'application/x-yaml'},
+            body='',
+        )
+        self.assertEqual(200, resp.status_code)
+
+    def test_request_with_no_content_type_on_get(self):
         resp = self.app.simulate_get(
-            '/versions', headers={'Content-Type': 'application/x-yaml'})
+            '/versions',
+            headers={})
+        self.assertEqual(200, resp.status_code)
+
+    def test_request_with_superfluous_content_type_on_get(self):
+        resp = self.app.simulate_get(
+            '/versions',
+            headers={'Content-Type': 'application/x-yaml'},
+        )
         self.assertEqual(200, resp.status_code)
 
     def test_request_with_correct_content_type_plus_encoding(self):
-        resp = self.app.simulate_get(
-            '/versions',
-            headers={'Content-Type': 'application/x-yaml;encoding=utf-8'})
+        rules = {'deckhand:create_cleartext_documents': '@'}
+        self.policy.set_rules(rules)
+        self._read_data('sample_document_simple')
+        resp = self.app.simulate_put(
+            '/api/v1.0/buckets/b1/documents',
+            headers={'Content-Type': 'application/x-yaml;encoding=utf-8'},
+            body=yaml.safe_dump(self.data),
+        )
         self.assertEqual(200, resp.status_code)
 
 
 class TestYAMLTranslatorNegative(test_base.BaseControllerTest):
 
     def test_request_without_content_type_raises_exception(self):
-        resp = self.app.simulate_get('/versions')
+        self._read_data('sample_document_simple')
+        resp = self.app.simulate_put(
+            '/api/v1.0/buckets/b1/documents',
+            body=yaml.safe_dump(self.data),
+        )
         self.assertEqual(400, resp.status_code)
 
         expected = {
@@ -60,8 +124,13 @@ class TestYAMLTranslatorNegative(test_base.BaseControllerTest):
         self.assertEqual(expected, yaml.safe_load(resp.content))
 
     def test_request_with_invalid_content_type_raises_exception(self):
-        resp = self.app.simulate_get(
-            '/versions', headers={'Content-Type': 'application/json'})
+        self._read_data('sample_document_simple')
+        resp = self.app.simulate_put(
+            '/api/v1.0/buckets/b1/documents',
+            headers={'Content-Type': 'application/json'},
+            body=yaml.safe_dump(self.data),
+        )
+
         self.assertEqual(415, resp.status_code)
 
         expected = {
@@ -91,12 +160,16 @@ class TestYAMLTranslatorNegative(test_base.BaseControllerTest):
         """Only application/x-yaml should be supported, not application/yaml,
         because it hasn't been registered as an official MIME type yet.
         """
-        resp = self.app.simulate_get(
-            '/versions', headers={'Content-Type': 'application/yaml'})
+        self._read_data('sample_document_simple')
+        resp = self.app.simulate_put(
+            '/api/v1.0/buckets/b1/documents',
+            headers={'Content-Type': 'application/yaml'},
+            body=yaml.safe_dump(self.data),
+        )
         self.assertEqual(415, resp.status_code)
 
         expected = {
-            'apiVersion': 'N/A',
+            'apiVersion': mock.ANY,
             'code': '415 Unsupported Media Type',
             'details': {
                 'errorCount': 1,

deckhand/tests/unit/resources/sample_document_simple.yaml

@@ -0,0 +1,17 @@
+---
+schema: armada/Manifest/v1.0
+metadata:
+  schema: metadata/Document/v1.0
+  name: cluster-bootstrap
+  layeringDefinition:
+    abstract: false
+    layer: site
+data:
+  release_prefix: ucp
+  chart_groups:
+    - kubernetes-proxy
+    - container-networking
+    - dns
+    - kubernetes
+    - kubernetes-rbac
+...