9694ae8c23
Right now we ensure that services are enabled/disabled while running playbooks only for core services. At the same time some services still do not have this mechanism, that might result in unexpected outages. So we ensure that all service playbooks will behave in the same way and disable backends in advance before playbook will do any modifications. With that, setting variable `haproxy_drain: true` will ensure that moving backend to the MAINT state will be graceful and all current connections will close normally unless a timeout is reached, which is 2 min by default. Closes-Bug: #2047017 Change-Id: I8554defec4df54d14be72ae9a1560907ff1aaddf