robust check for HA environment setup

awx/main/ha.py

@@ -1,11 +1,16 @@
 # Copyright (c) 2015 Ansible, Inc.
 # All Rights Reserved.
 
+# Python
+import os
+from IPy import IP
+
+# Django
 from django.conf import settings
 
+# AWX
 from awx.main.models import Instance
 
-
 def is_ha_environment():
     """Return True if this is an HA environment, and False
     otherwise.
@@ -16,8 +21,24 @@ def is_ha_environment():
 
     # If the database is not local, then we are in an HA environment.
     host = settings.DATABASES['default'].get('HOST', 'localhost')
-    if host and host.lower() not in ('127.0.0.1', 'localhost') and not host.startswith('/'):
-        return True
 
-    # We are not in an HA environment.
-    return False
+    # Is host special case 'localhost' ?
+    if host is 'localhost':
+        return False
+
+    # Check if host is an absolute file (i.e. named socket)
+    if os.path.isabs(host):
+        return False
+
+    # Is host a LOCAL or REMOTE ip address ?
+    try:
+        if IP(host).iptype() is 'LOOPBACK':
+            return False
+        else:
+            return True
+    except ValueError:
+        pass
+
+    # host may be a domain name like postgres.mycompany.com
+    # Assume HA Environment
+    return True