worker_processes auto;
error_log /var/log/nginx/error.log warn;
pid /tmp/nginx.pid;

events {
    worker_connections 1024;
}

http {
    include       /etc/nginx/mime.types;
    default_type  text/html;
    sendfile      on;
    server_tokens off;
    charset       utf-8;

    map $http_upgrade $connection_upgrade {
        default upgrade;
        ""      close;
    }

    map $status $error_title {
        default "Service Unavailable";
        404     "Not Found";
        500     "Internal Server Error";
        502     "Bad Gateway";
        503     "Service Unavailable";
        504     "Gateway Timeout";
    }

    map $status $error_message {
        default "We're working to resolve the issue.<br />Please try again shortly.";
        404     "The page you're looking for could not be found.";
    }

    include /etc/nginx/upstreams.map;

    server {
        listen 127.0.0.1:4098;
        server_name _;

        root /usr/share/nginx/html;
        absolute_redirect off;

        location = /healthz {
            access_log off;
            default_type text/plain;
            return 200 "ok\n";
        }

        error_page 404 500 502 503 504 /__error/index.html;

        location = /__error/index.html {
            internal;
            sub_filter_once off;
            sub_filter_types text/html;
            sub_filter "__STATUS__" $status;
            sub_filter "__ERROR_TITLE__" $error_title;
            sub_filter "__ERROR_MESSAGE__" $error_message;
            sub_filter "__HOST__" $host;
            add_header Cache-Control "no-store" always;
            add_header X-Content-Type-Options "nosniff" always;
        }

        # API 404 stays with the app so JSON clients keep working.
        location /api/ {
            error_page 500 502 503 504 /__error/index.html;
            include /etc/nginx/proxy_to_app.conf;
        }

        location / {
            include /etc/nginx/proxy_to_app.conf;
        }
    }
}