Ensure that SERVICE_FIX has trailing slash.

Fixes Issue jupyterhub#997. Also updated Traitlets to 4.3.2 since the change in singleuser.py relies on trait default values being checked through validator, which was added in traitlets 4.3.2.

jupyterhub/services/service.py

@@ -204,7 +204,7 @@ def server(self):
 
     @property
     def prefix(self):
-        return url_path_join(self.base_url, 'services', self.name)
+        return url_path_join(self.base_url, 'services', self.name + '/')
 
     @property
     def proxy_path(self):

jupyterhub/singleuser.py

@@ -180,6 +180,17 @@ def _hub_api_url_default(self):
     def _base_url_default(self):
         return os.environ.get('JUPYTERHUB_SERVICE_PREFIX') or '/'
 
+    #Note: this may be removed if notebook module is >= 5.0.0b1
+    @validate('base_url')
+    def _validate_base_url(self, proposal):
+        """ensure base_url starts and ends with /"""
+        value = proposal.value
+        if not value.startswith('/'):
+            value = '/' + value
+        if not value.endswith('/'):
+            value = value + '/'
+        return value
+
     @default('cookie_name')
     def _cookie_name_default(self):
         if os.environ.get('JUPYTERHUB_SERVICE_NAME'):

requirements.txt

@@ -1,5 +1,5 @@
 alembic
-traitlets>=4.3
+traitlets>=4.3.2
 tornado>=4.1
 jinja2
 pamela