map $host $upstream_acme_challenge_host {
    club-assistant.ccchh.net 10.31.208.10;
    netbox.ccchh.net 10.31.208.29;
    thinkcccore0.ccchh.net 10.31.242.3;
    thinkcccore1.ccchh.net 10.31.242.4;
    thinkcccore2.ccchh.net 10.31.242.5;
    thinkcccore3.ccchh.net 10.31.242.6;
    default "";
}

server {
    listen 80 default_server;

    location /.well-known/acme-challenge/ {
        proxy_pass http://$upstream_acme_challenge_host;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        # This is http in any case.
        proxy_set_header X-Forwarded-Proto http;
    }
}

server {
    listen 443 ssl http2 default_server;

    # ssl_certificate /path/to/signed_cert_plus_intermediates;
    # ssl_certificate_key /path/to/private_key;
    # # verify chain of trust of OCSP response using Root CA and Intermediate certs
    # ssl_trusted_certificate /path/to/root_CA_cert_plus_intermediates;
    ssl_certificate /etc/ssl/certs/public-reverse-proxy.crt;
    ssl_certificate_key /etc/ssl/private/public-reverse-proxy.key;

    # HSTS (ngx_http_headers_module is required) (63072000 seconds)
    add_header Strict-Transport-Security "max-age=63072000" always;

    # replace with the IP address of your resolver
    resolver 127.0.0.1;

    location /.well-known/acme-challenge/ {
        proxy_pass http://$upstream_acme_challenge_host;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        # This is http in any case.
        proxy_set_header X-Forwarded-Proto https;
    }
}