enable configuration of allowed host

Signed-off-by: Pierre Tardy <pierre.tardy@renault.com>

Author: tardyp

README.rst

@@ -160,6 +160,11 @@ for this purpose::
 
     SECRET_KEY=$(python -c "from django.core.management import utils; print(utils.get_random_secret_key())")
 
+You will also need to setup the VC_ALLOWED_HOSTS environment variable to match the hostname where the app is deployed::
+
+    VC_ALLOWED_HOSTS=vulnerablecode.your.domain.example.com
+
+You can specify several host by separating them with a colon `:`
 
 Using Nix
 ~~~~~~~~~

vulnerablecode/settings.py

@@ -27,9 +27,7 @@
 # SECURITY WARNING: don't run with debug turned on in production!
 DEBUG = False
 
-ALLOWED_HOSTS = [
-    ".herokuapp.com",
-]
+ALLOWED_HOSTS = os.environ.get("VC_ALLOWED_HOSTS", "*").split(":")
 
 # Application definition