动态生成配置文件 -- confd

confd项目地址

https://github.com/kelseyhightower/confd

1. 下载confd：

   wget https://github.com/kelseyhightower/confd/releases/download/v0.16.0/confd-0.16.0-linux-amd64
   mv confd-0.16.0-linux-amd64 /usr/bin/confd
   chmod +x /usr/bin/confd

2. 创建配置文件及模板目录：
   mkdir -p /etc/confd/{conf.d,templates}

3. 创建总配置文件：
   vim /etc/confd/confd.toml

   backend = "etcdv3"
   confdir = "/etc/confd"
   log-level = "info"
   #interval = 5
   # etcd 节点地址
   nodes = ["http://127.0.0.1:2379"]
   scheme = "http"
   watch = true

4. 创建单个服务的配置文件：
   vim /etc/confd/conf.d/my-server.toml

   [template]
   # 模板文件路径
   src = "my-server.tmpl"
   # 生成的配置文件路径
   dest = "/etc/nginx/conf.d/my-server.conf"
   # 监听的 key
   keys = [
    "/nginx/my-server/",
   ]
   # 生成文件后执行的命令
   check_cmd = "/sbin/nginx -t"
   reload_cmd = "/bin/systemctl restart nginx"

5. 创建模板文件：
   vim /etc/confd/templates/my-server.tmpl

    upstream my_server {
        {{range getvs "/nginx/my-server/*"}}
            server {{.}};
        {{end}}
    }
    server {
        listen 80;
        server_name localhost;
        location / {
            proxy_pass http://my_server;
            proxy_redirect off;
            proxy_set_header Host $host:$server_port;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_read_timeout 90;
        }
    }

6. 启动：

   # 生成一次并退出
   confd -onetime -backend etcd -node http://127.0.0.1:2379
   # 持续监听 key 的变化
   confd -watch -backend etcd -node http://127.0.0.1:2379

7. 验证：

   etcdctl put /nginx/my-server/server1  10.0.0.11:8080
   etcdctl put /nginx/my-server/server2  10.0.0.12:8080