# cd /usr/local/src
# wget https://nginx.org/download/nginx-1.20.2.tar.gz
# tar zxf nginx-1.20.2.tar.gz
# git clone https://github.com/yaoweibin/nginx_upstream_check_module.git
# ls -l
total 1044
drwxr-xr-x 8 1001 1001     158 Nov 16  2021 nginx-1.20.2
-rw-r--r-- 1 root root 1062124 Nov 16  2021 nginx-1.20.2.tar.gz
drwxr-xr-x 7 root root    4096 Jul 20 23:50 nginx_upstream_check_module

# cd nginx-1.20.2
# patch -p1 < /usr/local/src/nginx_upstream_check_module/check_1.20.1+.patch
patching file src/http/modules/ngx_http_upstream_hash_module.c
patching file src/http/modules/ngx_http_upstream_ip_hash_module.c
patching file src/http/modules/ngx_http_upstream_least_conn_module.c
patching file src/http/ngx_http_upstream_round_robin.c
patching file src/http/ngx_http_upstream_round_robin.h

# ./configure --prefix=/usr/local/nginx --user=nginx --group=nginx --with-compat --with-file-aio --with-threads --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_flv_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_mp4_module --with-http_random_index_module --with-http_realip_module --with-http_secure_link_module --with-http_slice_module --with-http_ssl_module --with-http_stub_status_module --with-http_sub_module --with-http_v2_module --with-mail --with-mail_ssl_module --with-stream --with-stream_realip_module --with-stream_geoip_module --with-stream_ssl_module --with-stream_ssl_preread_module --with-pcre --with-pcre-jit --with-stream_geoip_module --add-module=/usr/local/src/nginx_upstream_check_module
# make && make install

# cat conf/conf.d/nginx_upstream_check.conf
upstream cluster{
    server 192.168.100.210:9091;
    server 192.168.100.210:9092;
    check interval=3000 rise=2 fall=2 timeout=3000 type=http;
    check_http_send "GET /ops/v1/check HTTP/1.0\r\n\r\n ";
    check_http_expect_alive http_2xx http_3xx;
}


server {
    listen       8888;
    server_name  localhost;
    #charset koi8-r;
    access_log  logs/nginx_upstream_check.log  main;

    location / {
        root   html;
        index  index.html;
    }

    location ^~ /nginxServer/ {
        proxy_pass http://cluster/;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Proto https;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header REMOTE-HOST $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_pass_request_body on;
        proxy_set_header   Cookie $http_cookie;
        real_ip_header X-Real-IP;
    }

    location /nginx_status {
        check_status;
        access_log off;
    }
}

check interval=milliseconds [fall=count] [rise=count] [timeout=milliseconds] [default_down=true|false] [type=tcp|http|ssl_hello|mysql|ajp] [port=check_port]

You can specify the default display format. The formats can be `html`,
    `csv` or `json`. The default type is `html`. It also supports to specify
    the format by the request argument. Suppose your `check_status` location
    is '/status', the argument of `format` can change the display page's
    format. You can do like this:

        /status?format=html
        /status?format=csv
        /status?format=json

    At present, you can fetch the list of servers with the same status by
    the argument of `status`. For example:

        /status?format=html&status=down
        /status?format=csv&status=up