Add support for cache control headers (fixes #21)

CHANGELOG.rst

@@ -4,8 +4,9 @@ CHANGELOG
 0.4.0 (unreleased)
 ------------------
 
-- Nothing changed yet.
+**New features**
 
+- Add support for cache control headers (``If-None-Match`` and ``If-Modified-Since``) (fixes #21)
 
 0.3.0 (2016-10-27)
 ------------------

Makefile

@@ -1,4 +1,4 @@
-VIRTUALENV = virtualenv
+VIRTUALENV = virtualenv --python=python3
 VENV := $(shell echo $${VIRTUAL_ENV-.venv})
 PYTHON = $(VENV)/bin/python
 INSTALL_STAMP = $(VENV)/.install.stamp
@@ -24,13 +24,10 @@ build-requirements:
 
 virtualenv: $(PYTHON)
 $(PYTHON):
-	virtualenv $(VENV)
-
-moto:
-	$(VENV)/bin/moto_server s3bucket_path -H 0.0.0.0 -p 5000
+	$(VIRTUALENV) $(VENV)
 
 tests-once: install
-	$(VENV)/bin/tox -e py27
+	$(VENV)/bin/tox -e py35
 
 tests:
 	$(VENV)/bin/tox

kinto_amo/tests/support.py

@@ -17,8 +17,9 @@ class AMOTestCase(BaseWebTest, unittest.TestCase):
     entry_point = kinto_main
     config = 'config.ini'
 
-    def get_app_settings(self, extras=None):
-        ini_path = os.path.join(HERE, self.config)
+    @classmethod
+    def get_app_settings(cls, extras=None):
+        ini_path = os.path.join(HERE, cls.config)
         config = configparser.ConfigParser()
         config.read(ini_path)
         settings = dict(config.items('app:main'))

kinto_amo/tests/test_views.py

@@ -18,13 +18,43 @@
 
 
 class AMOTest(AMOTestCase):
+    url = SERVICE_ENDPOINT.format(api_ver="3",
+                                  app=constants.FIREFOX_APPID,
+                                  app_ver="46.0")
+
     def test_amo_view_returns_xml(self):
-        url = SERVICE_ENDPOINT.format(api_ver="3",
-                                      app=constants.FIREFOX_APPID,
-                                      app_ver="46.0")
-        resp = self.app.get(url)
+        resp = self.app.get(self.url)
         assert resp.content_type == "application/xml"
 
+    def test_has_etag_response_header(self):
+        resp = self.app.get(self.url)
+        assert "ETag" in resp.headers
+
+    def test_has_last_modified_response_header(self):
+        resp = self.app.get(self.url)
+        assert "Last-Modified" in resp.headers
+
+    def test_returns_304_if_not_modified_since(self):
+        resp = self.app.get(self.url)
+        last_etag = resp.headers["ETag"]
+        last_modified = resp.headers["Last-Modified"]
+
+        resp = self.app.get(self.url, headers={"If-None-Match": last_etag})
+        assert resp.status_code == 304
+
+        resp = self.app.get(self.url, headers={"If-Modified-Since": last_modified})
+        assert resp.status_code == 304
+
+    def test_returns_200_if_not_modified_since_is_malformed(self):
+        # We don't want to break clients.
+        resp = self.app.get(self.url, headers={"If-Modified-Since": "semaine derniere"})
+        assert resp.status_code == 200
+
+    def test_returns_200_if_none_match_is_malformed(self):
+        # We don't want to break clients.
+        resp = self.app.get(self.url, headers={"If-None-Match": "42a"})
+        assert resp.status_code == 200
+
     def test_amo_view_only_match_numeric_api_ver(self):
         url = SERVICE_ENDPOINT.format(api_ver="wrong",
                                       app=constants.FIREFOX_APPID,
@@ -34,10 +64,7 @@ def test_amo_view_only_match_numeric_api_ver(self):
         assert resp.content_type == "application/json"
 
     def test_amo_view_also_match_with_metrics_args(self):
-        url = SERVICE_ENDPOINT.format(api_ver="3",
-                                      app=constants.FIREFOX_APPID,
-                                      app_ver="46.0")
-        url += ('PRODUCT/BUILD_ID/BUILD_TARGET/LOCALE/CHANNEL/'
+        url = self.url + ('PRODUCT/BUILD_ID/BUILD_TARGET/LOCALE/CHANNEL/'
                 'OS_VERSION/DISTRIBUTION/DISTRIBUTION_VERSION/'
                 'PING_COUNT/TOTAL_PING_COUNT/DAYS_SINCE_LAST_PING/')
         resp = self.app.get(url)
@@ -46,38 +73,26 @@ def test_amo_view_also_match_with_metrics_args(self):
 
     def test_amo_views_passes_api_ver_and_app_args_to_addons_exporter(self):
         with mock.patch('kinto_amo.views.services.write_addons_items') as wai:
-            url = SERVICE_ENDPOINT.format(api_ver="3",
-                                          app=constants.FIREFOX_APPID,
-                                          app_ver="46.0")
-            self.app.get(url)
+            self.app.get(self.url)
             assert wai.mock_calls[0][2] == {'api_ver': 3,
                                             'app_id': constants.FIREFOX_APPID}
 
     def test_amo_views_passes_api_and_app_ver_args_to_plugin_exporter(self):
         with mock.patch('kinto_amo.views.services.write_plugin_items') as wpi:
-            url = SERVICE_ENDPOINT.format(api_ver="3",
-                                          app=constants.FIREFOX_APPID,
-                                          app_ver="46.0")
-            self.app.get(url)
+            self.app.get(self.url)
             assert wpi.mock_calls[0][2] == {'api_ver': 3,
                                             'app_id': constants.FIREFOX_APPID,
                                             'app_ver': "46.0"}
 
     def test_amo_views_passes_api_and_app_args_to_gfx_exporter(self):
         with mock.patch('kinto_amo.views.services.write_gfx_items') as wgi:
-            url = SERVICE_ENDPOINT.format(api_ver="3",
-                                          app=constants.FIREFOX_APPID,
-                                          app_ver="46.0")
-            self.app.get(url)
+            self.app.get(self.url)
             assert wgi.mock_calls[0][2] == {'api_ver': 3,
                                             'app_id': constants.FIREFOX_APPID}
 
     def test_amo_views_passes_api_and_app_args_to_certificates_exporter(self):
         with mock.patch('kinto_amo.views.services.write_cert_items') as wci:
-            url = SERVICE_ENDPOINT.format(api_ver="3",
-                                          app=constants.FIREFOX_APPID,
-                                          app_ver="46.0")
-            self.app.get(url)
+            self.app.get(self.url)
             assert wci.mock_calls[0][2] == {'api_ver': 3}
 
 
@@ -200,8 +215,9 @@ def test_not_enabled_gfx_are_ignored(self):
 
 class AMOCustomTest(AMOTestCase):
 
-    def get_app_settings(self, extras=None):
-        settings = super(AMOCustomTest, self).get_app_settings(extras)
+    @classmethod
+    def get_app_settings(cls, extras=None):
+        settings = super().get_app_settings(extras)
         settings['amo.preview.addons'] = '/buckets/blocklists/collections/addons'
         settings['amo.preview.plugins'] = '/buckets/blocklists/collections/plugins'
         settings['amo.preview.gfx'] = '/buckets/blocklists/collections/gfx'

kinto_amo/views/services.py

@@ -1,4 +1,4 @@
-from pyramid.httpexceptions import HTTPNotFound
+from pyramid.httpexceptions import HTTPNotFound, HTTPNotModified
 from kinto.core import Service, utils
 from kinto.core.storage import Filter
 
@@ -48,6 +48,20 @@ def get_blocklist(request):
     if cert_records:
         last_update = max(last_update, cert_records[-1]['last_modified'])
 
+    # Expose highest timestamp in response headers.
+    last_etag = '"{}"'.format(last_update)
+    request.response.headers['ETag'] = last_etag
+    request.response.last_modified = last_update / 1000.0
+
+    if_none_match = request.headers.get('If-None-Match')
+    if_modified_since = request.headers.get('If-Modified-Since')
+    if if_none_match is not None or if_modified_since is not None:
+        if if_none_match == last_etag or request.if_modified_since == request.response.last_modified:
+            response = HTTPNotModified()
+            response.headers['ETag'] = last_etag
+            response.last_modified = last_update / 1000.0
+            raise response
+
     xml_tree = etree.Element(
         'blocklist',
         xmlns="http://www.mozilla.org/2006/addons-blocklist",

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,py34,kinto-master,flake8
+envlist = py35,kinto-master,flake8
 
 [testenv]
 commands =