Haproxy hitless reload

https://www.haproxy.com/documentation/hapee/latest/api/runtime-api/overview/

https://www.haproxy.com/blog/haproxy-process-management/

https://github.com/snorwin/haproxy-reload-wrapper/blob/main/main.go

https://stackoverflow.com/questions/52725226/docker-compose-entrypoint-using-command-exit-code-as-a-failure-detection-mechani

https://cdn.haproxy.com/wp-content/uploads/2020/04/20.-Master-CLI_Configuration.png

https://www.haproxy.com/blog/truly-seamless-reloads-with-haproxy-no-more-hacks/

https://www.haproxy.org/download/2.6/doc/configuration.txt