Comment 5 for bug 1795027

Meh the plan 1-2) above won't be as simple because we have the following option in the undercloud install:
    if CONF.get('enable_zaqar'): deploy_args += ['-e', os.path.join(
            tht_templates, "environments/services/zaqar.yaml")]

So in order to keep the 'enable_zaqar' feature unchanged we'd have to add something like 'environments/services/zaqar-noredis.yaml' and use that one to avoid redis on the undercloud by default.