#user  root;
worker_processes  1;
error_log  logs/error.log  info;
#error_log  logs/debug_stream.log  debug_stream;
error_log  logs/debug_http.log  debug_http;
#pid        logs/nginx.pid;

events {
    worker_connections  256;
}
http {
   log_format  main  '$remote_addr:$remote_port -> $server_addr:$server_port [$time_local] "$request" '
                  '$status $body_bytes_sent "$http_referer" '
                  '"$http_user_agent" "$http_x_forwarded_for"';
    access_log logs/access.log main;
    server {
        listen 8081;
        # status interface
        location /status {
            healthcheck_status json;
        }
        # http front
        location / { 
          proxy_pass http://http-cluster;
        }   
    }
    # as a backend server1.
    server {
        listen 127.0.0.1:8082;
        location / {
          default_type application/json ;
          return 201  '{"name":"server1","status": "UP"}';
        }
    }
    # as a backend server2.
    server {
        listen 127.0.0.2:8082;
        location / {
          default_type application/json ;
          return 202  '{"name":"server2","status": "DOWN"}';
        }
    }
    
    upstream http-cluster {
        # simple round-robin
        server 127.0.0.1:8082;
        server 127.0.0.2:8082;

        check interval=3000 rise=2 fall=5 timeout=5000 type=http;
        check_http_send "GET /heartbeat HTTP/1.0\r\n\r\n";
        check_http_expect_alive http_2xx http_3xx;
        # I just wanna enable servers whose response content contain ('server1' or 'server3') and 'UP'
        check_http_expect_body ~ "server[13].+UP";
    }
}

stream {
    upstream tcp-cluster {
        # simple round-robin
        server 127.0.0.1:22; # nomarl
        server 192.168.0.2:22;
        check interval=3000 rise=2 fall=5 timeout=5000 default_down=true type=tcp;
        #check_http_send "UDP_TEST";
    }
    upstream udp-cluster {
        # simple round-robin
        server 127.0.0.1:5432; # port unreachable
        server 8.8.8.8:5432; # no error icmp msg
        check interval=3000 rise=2 fall=5 timeout=5000 default_down=true type=udp;
        check_http_send "UDP_TEST";
    }

    upstream http-cluster2 {
        # simple round-robin
        server 127.0.0.1:8082;
        server 127.0.0.2:8082;

        check interval=3000 rise=1 fall=1 timeout=5000 type=http;
        #check_http_send "GET /heartbeat2 HTTP/1.1\r\nHost: localhost\r\n\r\n";
        check_http_send "GET /heartbeat2 HTTP/1.0\r\nConnection: Keep-Alive\r\n\r\n";
        # when use keepalive, you must use HTTP/1.1 with Host like above, or use HTTP/1.0 with header 'Connection: Keep-Alive'
        check_keepalive_requests 10;
        check_http_expect_alive http_2xx http_3xx;
        # I just wanna enable servers whose response content contain ('server1' or 'server3') and 'UP'
        check_http_expect_body ~ "server[13].+UP";
    }
}