[progbits]

What's annoying about the built-in checker is that it attempts to connect proxypass backends. So if you want to run this in CI you will get connection refused errors.

[ndsipa_pomu]

Put the proxy settings into variables and you can sidestep that. It also allows NgINX to start up when the backends may not be running.

e.g.

    set $upstream_app         backend;
    set $upstream_port        8888;
    set $upstream_proto       http;
    proxy_pass                $upstream_proto://$upstream_app:$upstream_port;

[zelphirkalt]

On the other hand, if it never checked those, you would run into problems, when you rely on those being available and somehow they are not.