[AIRFLOW-227] Show running config in config view

Right now the config page (when set to display)
just loads the airflow.cfg and lists that.
So any configuration values that are set via
an environment variable are not shown.

This patch makes all configuration values
which are loaded via any means shown,
only if expose_config is set to true.

Closes apache#1597 from sekikn/AIRFLOW-227

airflow/www/templates/airflow/config.html

@@ -0,0 +1,69 @@
+{#
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+#}
+{% extends "airflow/master.html" %}
+
+{% block title %}
+    {{ title }}
+{% endblock %}
+
+{% block body %}
+    {{ super() }}
+    <h2>{{ title }}</h2>
+
+    {% if pre_subtitle %}
+        <pre>{{ pre_subtitle }}</pre>
+    {% endif %}
+
+    {% if subtitle %}
+        <h5>{{ subtitle }}</h5>
+    {% endif %}
+
+    {% if code %}
+        <pre>{{ code }}</pre>
+    {% endif %}
+
+    {% if code_html %}
+        {{ code_html|safe }}
+    {% endif %}
+
+    <hr>
+
+    {% if table %}
+        <br>
+        <h3>Running Configuration</h3>
+        <br>
+        <div>
+            <table class="table table-striped table-bordered">
+                <tr>
+                    <th>Section</th>
+                    <th>Key</th>
+                    <th>Value</th>
+                    <th>Source</th>
+                </tr>
+                {% for section, key, value, source in table %}
+                    <tr>
+                        <td>{{ section }}</td>
+                        <td>{{ key }}</td>
+                        <td class='code'>{{ value }}</td>
+                        <td>{{ source }}</td>
+                    </tr>
+                {% endfor %}
+            </table>
+        </div>
+    {% endif %}
+{% endblock %}

airflow/www/views.py

@@ -2511,10 +2511,15 @@ def conf(self):
         if conf.getboolean("webserver", "expose_config"):
             with open(conf.AIRFLOW_CONFIG, 'r') as f:
                 config = f.read()
+            table = [(section, key, value, source)
+                     for section, parameters in conf.as_dict(True, True).items()
+                     for key, (value, source) in parameters.items()]
+
         else:
             config = (
                 "# You Airflow administrator chose not to expose the "
                 "configuration, most likely for security reasons.")
+            table = None
         if raw:
             return Response(
                 response=config,
@@ -2527,9 +2532,10 @@ def conf(self):
                 HtmlFormatter(noclasses=True))
             )
             return self.render(
-                'airflow/code.html',
+                'airflow/config.html',
                 pre_subtitle=settings.HEADER + "  v" + airflow.__version__,
-                code_html=code_html, title=title, subtitle=subtitle)
+                code_html=code_html, title=title, subtitle=subtitle,
+                table=table)
 
 
 class DagModelView(wwwutils.SuperUserMixin, ModelView):

tests/core.py

@@ -1272,6 +1272,7 @@ class WebUiTests(unittest.TestCase):
     def setUp(self):
         configuration.load_test_config()
         configuration.conf.set("webserver", "authenticate", "False")
+        configuration.conf.set("webserver", "expose_config", "True")
         app = application.create_app()
         app.config['TESTING'] = True
         self.app = app.test_client()
@@ -1327,6 +1328,7 @@ def test_dag_views(self):
         response = self.app.get(
             '/admin/configurationview/')
         assert "Airflow Configuration" in response.data.decode('utf-8')
+        assert "Running Configuration" in response.data.decode('utf-8')
         response = self.app.get(
             '/admin/airflow/rendered?'
             'task_id=runme_1&dag_id=example_bash_operator&'
@@ -1435,6 +1437,7 @@ def test_fetch_task_instance(self):
         assert "runme_0" in response.data.decode('utf-8')
 
     def tearDown(self):
+        configuration.conf.set("webserver", "expose_config", "False")
         self.dag_bash.clear(start_date=DEFAULT_DATE, end_date=datetime.now())