如何修改 /etc/nginx/conf.d/*.conf 使 nginx 作为负载均衡器工作？

Question

我有两台服务器运行相同的 Web 服务，我有另一台服务器运行 nginx，它将用户请求重定向到两个 Web 服务器之一。

              /------> web server1 (10.56.0.1)
user --> nginx
              \------> web server2 (10.56.0.2)

我可以通过将upstream 和proxy_pass 直接添加到/etc/nginx/nginx.conf 来使其工作。

http {
    ...
    upstream backend {
        server 10.56.0.1:80;
        server 10.56.0.2:80;
    }   
    server {
        ...
        location / {
            proxy_pass http://backend;
        }
    }
}

但是我觉得直接改/etc/nginx/nginx.conf不是个好主意，我想把upstream和proxy_pass放到/etc/nginx/conf.d里面，但是不行，为什么？我的完整配置如下。

/etc/nginx/nginx.conf（未修改）

# For more information on configuration, see:
#   * Official English Documentation: http://nginx.org/en/docs/
#   * Official Russian Documentation: http://nginx.org/ru/docs/

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

# Load dynamic modules. See /usr/share/nginx/README.dynamic.
include /usr/share/nginx/modules/*.conf;

events {
    worker_connections 1024;
}

http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile            on;
    tcp_nopush          on;
    tcp_nodelay         on;
    keepalive_timeout   65;
    types_hash_max_size 2048;

    include             /etc/nginx/mime.types;
    default_type        application/octet-stream;

    # Load modular configuration files from the /etc/nginx/conf.d directory.
    # See http://nginx.org/en/docs/ngx_core_module.html#include
    # for more information.
    include /etc/nginx/conf.d/*.conf;

    server {
        listen       80 default_server;
        listen       [::]:80 default_server;
        server_name  _;
        root         /usr/share/nginx/html;

        # Load configuration files for the default server block.
        include /etc/nginx/default.d/*.conf;

        location / {
        }

        error_page 404 /404.html;
            location = /40x.html {
        }

        error_page 500 502 503 504 /50x.html;
            location = /50x.html {
        }
    }
}

/etc/nginx/conf.d/default.conf

upstream backend {
        server 10.56.0.1:80;
        server 10.56.0.2:80;
}

server {
        listen 80;

        location / {
                proxy_pass http://backend;
        }
}

Answer 1

你没有在文件“/etc/nginx/conf.d/default.conf”中提到任何server_name，另一方面你有 server_name _; 块 /etc/nginx/nginx.conf，所以所有流量都指向 nginx.conf 文件的服务器块。

我想建议从 nginx.conf 中删除以下行并将其放入 default.conf

server_name  _;

所以你的 default.conf 将是

upstream backend {

    server 10.56.0.1:80;
    server 10.56.0.2:80;
}

server {

    listen 80;
    server_name _;
    location / {

        proxy_pass http://backend;
    }
}

更多请关注https://www.nginx.com/resources/wiki/start/topics/examples/server_blocks/

Answer 2

感谢@solvease给出的提示，我通过注释/etc/nginx/nginx.conf中的server块并在/etc/nginx/conf.d/default.conf中添加server_name解决了这个问题。

/etc/nginx/nginx.conf 的变化：

# server {
#         listen       80 default_server;
#         listen       [::]:80 default_server;
#         server_name  _;
#         root         /usr/share/nginx/html;
# 
#         # Load configuration files for the default server block.
#         include /etc/nginx/default.d/*.conf;
# 
#         location / {
#         }
# 
#         error_page 404 /404.html;
#             location = /40x.html {
#         }
# 
#         error_page 500 502 503 504 /50x.html;
#             location = /50x.html {
#         }
#     }

/etc/nginx/conf.d/default.conf 的变化：

server {
    ...
    server_name _;
}