infrastructure/hosts/carbon/services/nginx.nix

{ pkgs, inputs, config, ... }:
let
  # define logging format in json 
  # https://grafana.com/grafana/dashboards/12559-loki-nginx-service-mesh-json-version/
  log_format = ''
    log_format json_analytics escape=json '{'
                               '"msec": "$msec", ' # request unixtime in seconds with a milliseconds resolution
                               '"connection": "$connection", ' # connection serial number
                               '"connection_requests": "$connection_requests", ' # number of requests made in connection
                       '"pid": "$pid", ' # process pid
                       '"request_id": "$request_id", ' # the unique request id
                       '"request_length": "$request_length", ' # request length (including headers and body)
                       '"remote_addr": "$remote_addr", ' # client IP
                       '"remote_user": "$remote_user", ' # client HTTP username
                       '"remote_port": "$remote_port", ' # client port
                       '"time_local": "$time_local", '
                       '"time_iso8601": "$time_iso8601", ' # local time in the ISO 8601 standard format
                       '"request": "$request", ' # full path no arguments if the request
                       '"request_uri": "$request_uri", ' # full path and arguments if the request
                       '"args": "$args", ' # args
                       '"status": "$status", ' # response status code
                       '"body_bytes_sent": "$body_bytes_sent", ' # the number of body bytes exclude headers sent to a client
                       '"bytes_sent": "$bytes_sent", ' # the number of bytes sent to a client
                       '"http_referer": "$http_referer", ' # HTTP referer
                       '"http_user_agent": "$http_user_agent", ' # user agent
                       '"http_x_forwarded_for": "$http_x_forwarded_for", ' # http_x_forwarded_for
                       '"http_host": "$http_host", ' # the request Host: header
                       '"server_name": "$server_name", ' # the name of the vhost serving the request
                       '"request_time": "$request_time", ' # request processing time in seconds with msec resolution
                       '"upstream": "$upstream_addr", ' # upstream backend server for proxied requests
                       '"upstream_connect_time": "$upstream_connect_time", ' # upstream handshake time incl. TLS
                       '"upstream_header_time": "$upstream_header_time", ' # time spent receiving upstream headers
                       '"upstream_response_time": "$upstream_response_time", ' # time spend receiving upstream body
                       '"upstream_response_length": "$upstream_response_length", ' # upstream response length
                       '"upstream_cache_status": "$upstream_cache_status", ' # cache HIT/MISS where applicable
                       '"ssl_protocol": "$ssl_protocol", ' # TLS protocol
                       '"ssl_cipher": "$ssl_cipher", ' # TLS cipher
                       '"scheme": "$scheme", ' # http or https
                       '"request_method": "$request_method", ' # request method
                       '"server_protocol": "$server_protocol", ' # request protocol, like HTTP/1.1 or HTTP/2.0
                       '"pipe": "$pipe", ' # "p" if request was pipelined, "." otherwise
                       '"gzip_ratio": "$gzip_ratio", '
                       '"http_cf_ray": "$http_cf_ray",'
                       '"geoip_country_code": "$geoip2_data_country_code"'
                       '}';

  '';
  # geoip2 module to get countries from addresses
  geoip2 = ''
    geoip2 /etc/GeoLite2-Country.mmdb {
        auto_reload 5m;
        $geoip2_metadata_country_build metadata build_epoch;
        $geoip2_data_country_code default=US source=$remote_addr country iso_code;
        $geoip2_data_country_name country names en;
    }

    geoip2 /etc/GeoLite2-City.mmdb {
        $geoip2_data_city_name default=London city names en;
    }

  '';
in
{
  services.nginx = {
    enable = true;
    additionalModules = [ pkgs.nginxModules.geoip2 ];

    # add logging to config  
    commonHttpConfig = ''
      ${geoip2}
      ${log_format}
    '';

    #access_log /var/log/nginx/json_access.log json_analytics;
    # ^^ adds logging to every host

    virtualHosts = {

      "www.${config.networking.domain}" = {
        forceSSL = true;
        enableACME = true;

        locations."/" = {
          root = pkgs.callPackage ../services/website/default.nix { };
        };

        extraConfig = ''
          access_log /var/log/nginx/$server_name-access.log json_analytics;
        '';
      };
      "${config.networking.domain}" = {
        forceSSL = true;
        enableACME = true;

        locations."/" = {
          root = pkgs.callPackage ../services/website/default.nix { };
        };

        extraConfig = ''
          error_page 404 /404.html;
          deny 3.1.202.244;
          deny 170.64.219.93;
          deny 91.215.85.43;
          client_max_body_size 900M;
          access_log /var/log/nginx/$server_name-access.log json_analytics;
        '';
      };
    };
  };

  security.acme = {
    acceptTerms = true;
    defaults.email = "admin+acme@4o1x5.dev";
  };

}