负载均衡器/反向代理: docker-swarm中的“连接到上游时暂时禁用上游服务器”？

Question

我在docker-swarm中运行1个manager和2个worker节点。

工作节点运行3个堆栈与php/nginx网站，所以这是site1，site2，在浏览器中加载"This is site*/(worker1 or worker2)“的site3。当我在其中一个节点上放置反向代理时，这可以很好地工作。

但我想在管理器节点上放置一个负载均衡器/反向代理，我还禁用了其他两个堆栈，因此在本例中，两个工作节点上都只有"site1“堆栈。他们的Ip是"10.0.14.16“和"10.0.14.17”。

这是LB/RP nignx配置文件。

   upstream site1_nginx  {
     server 10.0.14.16;
     server 10.0.14.17;
   }
   server {
       listen 80;
       server_name site1.local;

       location / {
           proxy_set_header Host $host;
           proxy_set_header X-Real-IP $remote_addr;
           proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
           proxy_pass http://site1_nginx;

       }
   }

这是nignx的docker组合文件：

version: '3'

services:
  nginx:
      image: nginx:latest
      deploy:
        placement:
          constraints:
            - node.role==manager
        mode: global
      ports:
          - "80:80"
      volumes:
          - "./conf.d/:/etc/nginx/conf.d"

      networks:
          - reprox
networks:
  reprox:
    external: true

但是当我创建服务时，我得到了这个错误：

loadbalancer_nginx.0.ua0z0l8gm18e@ubuntu-vm1    | 2019/10/11 14:36:00 [error] 6#6: *12 connect() failed (111: Connection refused) while connecting to upstream, client: 10.255.0.2, server: site1.local, request: "GET / HTTP/1.1", upstream: "http://10.0.14.17:80/", host: "site1.local"
loadbalancer_nginx.0.ua0z0l8gm18e@ubuntu-vm1    | 2019/10/11 14:36:00 [warn] 6#6: *12 upstream server temporarily disabled while connecting to upstream, client: 10.255.0.2, server: site1.local, request: "GET / HTTP/1.1", upstream: "http://10.0.14.17:80/", host: "site1.local"
loadbalancer_nginx.0.ua0z0l8gm18e@ubuntu-vm1    | 2019/10/11 14:36:00 [error] 6#6: *12 connect() failed (111: Connection refused) while connecting to upstream, client: 10.255.0.2, server: site1.local, request: "GET / HTTP/1.1", upstream: "http://10.0.14.16:80/", host: "site1.local"
loadbalancer_nginx.0.ua0z0l8gm18e@ubuntu-vm1    | 2019/10/11 14:36:00 [warn] 6#6: *12 upstream server temporarily disabled while connecting to upstream, client: 10.255.0.2, server: site1.local, request: "GET / HTTP/1.1", upstream: "http://10.0.14.16:80/", host: "site1.local"
loadbalancer_nginx.0.ua0z0l8gm18e@ubuntu-vm1    | 2019/10/11 14:36:01 [error] 6#6: *12 no live upstreams while connecting to upstream, client: 10.255.0.2, server: site1.local, request: "GET / HTTP/1.1", upstream: "http://site1_nginx/", host: "site1.local"

另外，如果需要，还可以使用site1 nginx站点配置：

server {
    listen 80 default_server;
    listen [::]:80 default_server;

    index index.php index.html;
    server_name site1.local;
    resolver 127.0.0.11;

    error_log  /var/log/nginx/error.log;
    access_log /var/log/nginx/access.log;
    root /code;

    location / {
        try_files $uri $uri/ =404;
    }

    location ~ \.php$ {
        set $upstream php:9000;        
        try_files $uri =404;
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_pass $upstream;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
    }
}

docker网络很好，我确实有一个覆盖网络和php和nignx之间的网络。

Answer 1

Docker swarm拥有自己的负载均衡器、网络和DNS系统。如果您希望使用自己的平衡器，则没有理由定义节点的IP地址，因为docker还为您提供了抽象并管理服务发现。

由于routing mesh的存在，使用IP路由的解决方案不会像您想象的那样工作。所有请求都会在不考虑获取流量的节点的情况下实现负载均衡。您可以访问IP1，由于路由mesh IP2可以处理请求。

您想要的是将您的站点引用为您已定义为服务名称的DNS记录。

像这样

upstream site1_nginx  {
    server site1:80;
}

site1 是 docker-compose.yml 中定义的服务名称（nginx 的 DNS 名称为 nginx）。您可以将该服务称为特定的副本，但随后您需要自己实现健康检查。

upstream site1_nginx  {
    server site1.1:80;
    server site1.2:80;
    server site1.3:80;
}