Improve database info

Support for MySQL, include SQLite persistence warning.

welcome/database.py

@@ -0,0 +1,22 @@
+from django.conf import settings
+
+
+def info():
+    db_settings = settings.DATABASES['default']
+    if 'postgres' in db_settings['ENGINE']:
+        engine = 'PostgreSQL'
+        url = '{HOST}:{PORT}/{NAME}'.format(**db_settings)
+    elif 'mysql' in db_settings['ENGINE']:
+        engine = 'MySQL'
+        url = '{HOST}:{PORT}/{NAME}'.format(**db_settings)
+    elif 'sqlite' in db_settings['ENGINE']:
+        engine = 'SQLite'
+        url = '{NAME}'.format(**db_settings)
+    else:
+        engine = 'unknown'
+        url = ''
+    return {
+        'engine': engine,
+        'url': url,
+        'is_sqlite': engine == 'SQLite',
+    }

welcome/templates/welcome/index.html

@@ -14,6 +14,7 @@
     #explanation { background:#eee; }
     #instructions { background:#f6f6f6; }
     #instructions ol li { margin: 0.2em 0 0.2em 2em; }
+    .warning { color: orange }
   </style>
 </head>
 
@@ -51,7 +52,15 @@
 <div id="hostname">
   <p>
     Server hostname: {{ hostname }}<br>
-    Database server: {{ database_info }}<br>
+    Database server: {{ database.engine }} ({{ database.url }})<br>
+    {% if database.is_sqlite %}
+    <span class="warning">
+      Data persistence warning:
+      You are currently using SQLite.
+      This is fine for development, but your data won't be persisted
+      across application deployments.
+    </span><br>
+    {% endif %}
     Page views: {{ count }}
   </p>
 </div>

welcome/views.py

@@ -2,30 +2,17 @@ import os
 from django.shortcuts import render
 from django.conf import settings
 
+from . import database
 from .models import PageView
 
 # Create your views here.
 
-
-def _database_info():
-    db_settings = settings.DATABASES['default']
-    if 'postgres' in db_settings['ENGINE']:
-        engine = 'PostgreSQL'
-        info = '{HOST}:{PORT}/{NAME}'.format(**db_settings)
-    else:
-        engine = 'SQLite'
-        info = '{NAME}'.format(**db_settings)
-    return '{} ({})'.format(engine, info)
-
-database_info = _database_info()
-
-
 def index(request):
     hostname = os.getenv('HOSTNAME', 'unknown')
     PageView.objects.create(hostname=hostname)
 
     return render(request, 'welcome/index.html', {
         'hostname': hostname,
-        'database_info': database_info,
+        'database': database.info(),
         'count': PageView.objects.count()
     })