Separate userinfo from the config endpoint (#1728)

* Separate userinfo from the config endpoint

previously information about if the user was logged in and their username
was part of the config endpoint.
However, the config endpoint was previously static, and has a cache control.
Rather than not caching the config, a new endpoint called "userinfo"
is created to handle that information.

The config endpoint still has the non-changing part of the authentication:

  config:
    authentication:
        requires_client_login:  True/False
        login: <uri to login endoint if requires_client_login is True>
        logout: <uri to logout endoint if requires_client_login is True>

The userinfo endpoint returns this information:

  userinfo:
    is_authenticated:  True/False
    username: <string if is_authenticated>

if authentication is not enabled then the config does not have an authentication key,
and userinfo returns None.

Also in the PR are a few minor code improvements and bug fixes

Co-authored-by: Colin Megill <colinmegill@gmail.com>

server/common/app_config.py

@@ -275,10 +275,7 @@ class AppConfig(object):
 
         if dataset_config.app__authentication_enable and auth.is_valid_authentication_type():
             config["authentication"] = {
-                "is_authenticated": auth.is_user_authenticated(),
                 "requires_client_login": auth.requires_client_login(),
-                "username": auth.get_user_name(),
-                "user_id": auth.get_user_id()
             }
             if auth.requires_client_login():
                 config["authentication"].update({
@@ -288,6 +285,29 @@ class AppConfig(object):
 
         return c
 
+    def get_client_userinfo(self, data_adaptor):
+        """
+        Return the userinfo as required by the /userinfo REST route
+        """
+
+        server_config = self.server_config
+        dataset_config = data_adaptor.dataset_config
+        auth = server_config.auth
+
+        # make sure the configuration has been checked.
+        self.check_config()
+
+        if dataset_config.app__authentication_enable and auth.is_valid_authentication_type():
+            userinfo = {}
+            userinfo["userinfo"] = {
+                "is_authenticated": auth.is_user_authenticated(),
+                "username": auth.get_user_name(),
+                "user_id": auth.get_user_id()
+            }
+            return userinfo
+        else:
+            return None
+
 
 class BaseConfig(object):
     """This class handles the mechanics of updating and checking attributes.

server/common/rest.py

@@ -121,6 +121,11 @@ def config_get(app_config, data_adaptor):
     return make_response(jsonify(config), HTTPStatus.OK)
 
 
+def userinfo_get(app_config, data_adaptor):
+    config = app_config.get_client_userinfo(data_adaptor)
+    return make_response(jsonify(config), HTTPStatus.OK)
+
+
 def annotations_obs_get(request, data_adaptor):
     fields = request.args.getlist("annotation-name", None)
     num_columns_requested = len(data_adaptor.get_obs_keys()) if len(fields) == 0 else len(fields)