部署etcd

解压etcd-v3.4.7-linux-amd64.tar.gz文件
tar -zxvf etcd-v3.4.7-linux-amd64.tar.gz
启动etcd服务
./etcd --logger=zap --data-dir=/etc/etcd --enable-v2=true
upsync模块只支持v2版本的API，一定要加上--enable-v2=true，默认为禁用

nginx配置

[root@k8smaster01 conf]# more nginx.conf
worker_processes  2;
events {
    worker_connections  1024;
}
http {
    include       mime.types;
     log_format main '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_for
warded_for" "$upstream_addr"  "$request_body"';
    sendfile        on;
    keepalive_timeout  65;

    upstream test {
        sticky name=test_1 path=/;
        upsync 127.0.0.1:2379/v2/keys/upstreams/test upsync_timeout=6m upsync_interval=500ms upsync_type=etcd strong_dependency=off;
#        upsync 192.168.23.1:8000/encode/etcd/upstreams/test upsync_timeout=6m upsync_interval=500ms upsync_type=etcd strong_dependency=off;
 #        upsync 127.0.0.1:8500/v1/kv/upstreams/test upsync_timeout=6m upsync_interval=500ms upsync_type=consul strong_dependency=off;
        upsync_dump_path /data/soft/openresty-1.13.6.1/nginx/conf/servers_test.conf;
        include /data/soft/openresty-1.13.6.1/nginx/conf/servers_test.conf;

        check interval=1000 rise=2 fall=2 timeout=3000 type=http default_down=false;
        check_http_send "HEAD / HTTP/1.0\r\n\r\n";
        check_http_expect_alive http_2xx http_3xx;
    }
    server {
        listen       8888;
        location /test {
             proxy_pass http://test;
        }
        location /upstream_show {
            upstream_show;
        }
        location /upstream_status {
            check_status;
            access_log off;
        }

        location / {
            default_type 'text/html';
            content_by_lua 'ngx.say("hello world")';
        }
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }
}

验证

1、往etcd写入数据

[root@k8smaster01 ~]# curl -X PUT http://127.0.0.1:2379/v2/keys/upstreams/test/192.168.23.101:80 -d value=""
{"action":"set","node":{"key":"/upstreams/test/192.168.23.101:80","value":"","modifiedIndex":4,"createdIndex":4}}
[root@k8smaster01 ~]# curl -X PUT http://127.0.0.1:2379/v2/keys/upstreams/test/192.168.23.101:80 -d value=""
{"action":"set","node":{"key":"/upstreams/test/192.168.23.101:80","value":"","modifiedIndex":5,"createdIndex":5},"prevNode":{"key":"/upstreams/test/192.168.23.101:80","value":"","modifiedIndex":4,"createdIndex":4}}
[root@k8smaster01 ~]#

2、浏览器查看upstream是否动态更新

 抓包查看底层原理

 1、手工往etcd加入数据

PUT /v2/keys/upstreams/test/192.168.23.101:80 HTTP/1.1
User-Agent: curl/7.29.0
Host: 127.0.0.1:2379
Accept: */*
Content-Length: 6
Content-Type: application/x-www-form-urlencoded

value=HTTP/1.1 200 OK
Access-Control-Allow-Headers: accept, content-type, authorization
Access-Control-Allow-Methods: POST, GET, OPTIONS, PUT, DELETE
Access-Control-Allow-Origin: *
Content-Type: application/json
X-Etcd-Cluster-Id: cdf818194e3a8c32
X-Etcd-Index: 7
X-Raft-Index: 9
X-Raft-Term: 3
Date: Fri, 29 Jul 2022 16:51:31 GMT
Content-Length: 215

{"action":"set","node":{"key":"/upstreams/test/192.168.23.101:80","value":"","modifiedIndex":7,"createdIndex":7},"prevNode":{"key":"/upstreams/test/192.168.23.101:80","value":"","modifiedIndex":5,"createdIndex":5}}

2、nginx全量更新etcd的upstream配置

GET /v2/keys/upstreams/test? HTTP/1.0
Host: 127.0.0.1
Accept: */*

HTTP/1.0 200 OK
Access-Control-Allow-Headers: accept, content-type, authorization
Access-Control-Allow-Methods: POST, GET, OPTIONS, PUT, DELETE
Access-Control-Allow-Origin: *
Content-Type: application/json
X-Etcd-Cluster-Id: cdf818194e3a8c32
X-Etcd-Index: 7
X-Raft-Index: 9
X-Raft-Term: 3
Date: Fri, 29 Jul 2022 16:51:31 GMT
Content-Length: 196

{"action":"get","node":{"key":"/upstreams/test","dir":true,"nodes":[{"key":"/upstreams/test/192.168.23.101:80","value":"","modifiedIndex":7,"createdIndex":7}],"modifiedIndex":4,"createdIndex":4}}

3、nginx监听etcd节点变化

GET /v2/keys/upstreams/test?wait=true&recursive=true&waitIndex=8 HTTP/1.0
Host: 127.0.0.1
Accept: */*

HTTP/1.0 200 OK
Access-Control-Allow-Headers: accept, content-type, authorization
Access-Control-Allow-Methods: POST, GET, OPTIONS, PUT, DELETE
Access-Control-Allow-Origin: *
Content-Type: application/json
X-Etcd-Cluster-Id: cdf818194e3a8c32
X-Etcd-Index: 7
X-Raft-Index: 9
X-Raft-Term: 3
Date: Fri, 29 Jul 2022 16:51:32 GMT

{"action":"set","node":{"key":"/upstreams/test/192.168.23.102:80","value":"","modifiedIndex":8,"createdIndex":8}}

4、总结：nginx启动后，一直监听etcd上的upstream节点的变化，如果节点发送变化，触发全量更新nginx对应的upstream的值到内存中，这抓包可以看出，etcd的更新与监听是两个不一样的url，比consul复杂。