-can_update = ['hostname', 'boot_state', 'model', 'version','key', 'session', 'boot_nonce', 'site_id'] + \
- Node.related_fields.keys()
+admin_only = [ 'key', 'session', 'boot_nonce', 'site_id']
+can_update = ['hostname', 'boot_state', 'model', 'version'] + admin_only