roles/nginx: Per-vhost logs

Signed-off-by: Alan Orth <alan.orth@gmail.com>

roles/nginx/templates/vhost.conf.j2

@@ -8,6 +8,9 @@ server {
 
     server_name {{ domain_name }} {{ domain_aliases }};
 
+    access_log  /var/log/nginx/{{ domain_name }}-access.log;
+    error_log   /var/log/nginx/{{ domain_name }}-error.log;
+
     location / {
         try_files $uri $uri/ =404;
     }