network 进阶版 (包含 nginx)

Question 1a: What command did you use to display the networked services?

netstat
Question 1b: Paste the output of the command.

    Active Internet connections (only servers)
    Proto Recv-Q Send-Q Local Address           Foreign Address         State      
    tcp        0      0 localhost:domain        0.0.0.0:*               LISTEN     
    tcp        0      0 0.0.0.0:ssh             0.0.0.0:*               LISTEN     
    tcp        0      0 localhost:3000          0.0.0.0:*               LISTEN     
    tcp        0      0 0.0.0.0:8096            0.0.0.0:*               LISTEN     
    tcp        0      0 localhost:33060         0.0.0.0:*               LISTEN     
    tcp        0      0 0.0.0.0:5000            0.0.0.0:*               LISTEN     
    tcp        0      0 localhost:mysql         0.0.0.0:*               LISTEN     
    tcp        0      0 localhost:42063         0.0.0.0:*               LISTEN     
    tcp        0      0 0.0.0.0:http            0.0.0.0:*               LISTEN     
    tcp6       0      0 [::]:ssh                [::]:*                  LISTEN     
    tcp6       0      0 [::]:5244               [::]:*                  LISTEN     
    tcp6       0      0 localhost:42063         [::]:*                  LISTEN     
    tcp6       0      0 [::]:http               [::]:*                  LISTEN     
    udp        0      0 0.0.0.0:43741           0.0.0.0:*                          
    udp        0      0 0.0.0.0:1900            0.0.0.0:*                          
    udp        0      0 localhost:domain        0.0.0.0:*                          
    udp        0      0 iZuf64e9ug9p2r9x:bootpc 0.0.0.0:*                          
    udp        0      0 iZuf64e9ug9p2r9xd:55448 0.0.0.0:*                          
    udp        0      0 0.0.0.0:7359            0.0.0.0:*                          
    udp        0      0 localhost:323           0.0.0.0:*                          
    udp        0      0 localhost:58039         0.0.0.0:*                          
    udp6       0      0 localhost:323           [::]:*                             
    raw6       0      0 [::]:ipv6-icmp          [::]:*                  7          
    Active UNIX domain sockets (only servers)
    Proto RefCnt Flags       Type       State         I-Node   Path
    unix  2      [ ACC ]     STREAM     LISTENING     18887    /run/uuidd/request
    unix  2      [ ACC ]     STREAM     LISTENING     11226310 /run/systemd/userdb/io.systemd.DynamicUser
    unix  2      [ ACC ]     STREAM     LISTENING     26241    /usr/local/cloudmonitor/local_data/argus.sock
    unix  2      [ ACC ]     SEQPACKET  LISTENING     13386    /run/udev/control
    unix  2      [ ACC ]     STREAM     LISTENING     13371    /run/systemd/fsck.progress
    unix  2      [ ACC ]     STREAM     LISTENING     13381    /run/systemd/journal/stdout
    unix  2      [ ACC ]     STREAM     LISTENING     98918    /run/user/1001/systemd/private
    unix  2      [ ACC ]     STREAM     LISTENING     98923    /run/user/1001/bus
    unix  2      [ ACC ]     STREAM     LISTENING     98924    /run/user/1001/gnupg/S.dirmngr
    unix  2      [ ACC ]     STREAM     LISTENING     98925    /run/user/1001/gnupg/S.gpg-agent.browser
    unix  2      [ ACC ]     STREAM     LISTENING     98926    /run/user/1001/gnupg/S.gpg-agent.extra
    unix  2      [ ACC ]     STREAM     LISTENING     98927    /run/user/1001/gnupg/S.gpg-agent.ssh
    unix  2      [ ACC ]     STREAM     LISTENING     98928    /run/user/1001/gnupg/S.gpg-agent
    unix  2      [ ACC ]     STREAM     LISTENING     11226912 /run/systemd/journal/io.systemd.journal
    unix  2      [ ACC ]     STREAM     LISTENING     98929    /run/user/1001/pk-debconf-socket
    unix  2      [ ACC ]     STREAM     LISTENING     11216897 /run/containerd/containerd.sock.ttrpc
    unix  2      [ ACC ]     STREAM     LISTENING     11227920 /tmp/dotnet-diagnostic-1223391-511743523-socket
    unix  2      [ ACC ]     STREAM     LISTENING     11216902 /run/containerd/containerd.sock
    unix  2      [ ACC ]     STREAM     LISTENING     11241197 /var/run/docker/metrics.sock
    unix  2      [ ACC ]     STREAM     LISTENING     11243004 /var/run/docker/libnetwork/3fdc8a1ceef3.sock
    unix  2      [ ACC ]     STREAM     LISTENING     26685    /tmp/.s.PGSQL.42063
    unix  2      [ ACC ]     STREAM     LISTENING     11253192 /var/run/mysqld/mysqlx.sock
    unix  2      [ ACC ]     STREAM     LISTENING     11253194 /var/run/mysqld/mysqld.sock
    unix  2      [ ACC ]     STREAM     LISTENING     6848300  /tmp/aliyun_assist_service.sock
    unix  2      [ ACC ]     STREAM     LISTENING     26240    /tmp/argus.sock
    unix  2      [ ACC ]     STREAM     LISTENING     11247111 /var/run/openvswitch/db.sock
    unix  2      [ ACC ]     STREAM     LISTENING     11247112 /var/run/openvswitch/ovsdb-server.1228681.ctl
    unix  2      [ ACC ]     STREAM     LISTENING     11226308 /run/systemd/private
    unix  2      [ ACC ]     STREAM     LISTENING     18883    /run/dbus/system_bus_socket
    unix  2      [ ACC ]     STREAM     LISTENING     11247265 /var/run/openvswitch/ovs-vswitchd.1228731.ctl
    unix  2      [ ACC ]     STREAM     LISTENING     18885    /run/docker.sock

Question 1c: Choose one service from the output and describe what it does.

ssh, 远程链接

Q: Why is this the case? What DNS server are requests currently being sent to if @localhost is not specified in the command? A: dig www.baidu.com @localhost 指定了在本地的 DNS 服务器查询 www.baidu.com 相关的记录，但是这个时候本地的 DNS 服务器是处于关闭状态的。

Question 2a: What is the systemctl command to show whether bind9 is running or not?

systemctl status
Question 2b: Why does the dig command (dig ocf.berkeley.edu) work if @localhost is not present at the end (if bind9 is not started) but times out when @localhost is added?

A: dig www.baidu.com @localhost 指定了在本地的 DNS 服务器查询 www.baidu.com 相关的记录，但是这个时候本地的 DNS 服务器是处于关闭状态的。

Question 2c: What additional entries did you add to your DNS server config (the db.example.com file)?

test1 IN CNAME test
Question 2d: What commands did you use to make requests to the local DNS server for your additional entries?

dig

nginx (engine x) 文档

Beginners guide

How start, stop and reload
explains the structure of the configruation file
how to set up nginx to serve out static content
how to configure nginx as a proxy server
how to connect it with a FastCGI application

nginx 的配置文件由两种 directive 构成

simple directive 由名字和参数构成，中间由空格分开，结尾有分号
block directive 构成与 simple directive 类似，但是以一对 {} 结尾，没有分号。在括号内部可以定义其他的 directive

最外层的 directive 叫作 main directive, 比如 event http

如何设置反向代理？

在 nginx.conf 的 http context 下，加入 server 的配置语句即可。server 的写法可参考 sites-enable/myblog.trace1729.top

如何设置 SSL 证书？

首先，我们需要去阿里云控制台为我们的二级域名注册一个ssl证书 ssl证书注册平台。(只需要填写二级域名和联系方式即可，其余默认设置)

审核通过后，下载 ssl 证书并上传到服务器 (/etc/nginx/cert/)。(.key 和 .pem 文件)

在 nginx.conf 添加如下配置

server {
    server_name cloud.trace1729.top;
    rewrite ^(.*)$  https://$host$1 permanent; # 重定向到 https
}

server {
    listen 443 ssl;
    server_name cloud.trace1729.top; # 填写注册的域名
    ssl_certificate cert/cloud.trace1729.top.pem; # 证书名称
    ssl_certificate_key cert/cloud.trace1729.top.key; # 证书密钥
    ssl_session_timeout 5m;
    ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE:ECDH:AES:HIGH:!NULL:!aNULL:!MD5:!ADH:!RC4;
    ssl_protocols TLSv1.1 TLSv1.2 TLSv1.3;
    ssl_prefer_server_ciphers on;

    location / {
    proxy_pass http://localhost:5244;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    }

}

haproxy 配置负载均衡

刷新页面多次，有什么规律吗？按照 1, 2, 3, 4, 5 的顺序改变
负载均衡的算法是什么 round-robin

你加的配置是什么?

global
    maxconn 50000
    log /dev/log local0
    user haproxy
    group haproxy
    stats socket /run/haproxy/admin.sock user haproxy group haproxy mode 660 level admin
    cpu-map auto:1/1-4 0-3
    ssl-default-bind-ciphers ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256
    ssl-default-bind-options ssl-min-ver TLSv1.2 no-tls-tickets



defaults
    timeout connect 10s
    timeout client 30s
    timeout server 30s
    log global
    mode http
    option httplog
    maxconn 3000


listen stats
  bind    0.0.0.0:7001
  mode    http
  stats   enable
  stats   hide-version
  stats   uri /stats

frontend web.trace1729.top
    bind 0.0.0.0:7000
    default_backend web_servers


backend web_servers
    balance roundrobin
    cookie SERVERUSED insert indirect nocache
    default-server check maxconn 20
    server server1 0.0.0.0:8082 cookie server1
    server server2 0.0.0.0:8081 cookie server2
    server server3 0.0.0.0:8082 cookie server3
    server server4 0.0.0.0:8083 cookie server4
    server server5 0.0.0.0:8084 cookie server5

不知为何，这里的 ip 地址一定要写成 0.0.0.0 才能成功。我很好奇 0.0.0.0, localhost, 服务器公网地址, 127.0.0.1 这些地址的区别。

总结一下配置要点首先 frontend 接受用户的请求，让后将请求转发给 backend 的服务器。 backend 更具声明的调度算法选择服务器。再把服务器的返回结果发给 frontend

Total change, green
red
503 service unavaliable

network 进阶版 (包含 nginx)

nginx (engine x) 文档

颜色主题调整

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