一、centos系统初始化

1.1 设置IP

####1、查看ip
[root@rancher ~]# ip addr

根据显示的网卡，我们需要修改ens33的网卡信息

#####2、修改网卡信息
[root@rancher ~]# vim /etc/sysconfig/network-scripts/ifcfg-ens33
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=ens33
UUID=00617e9f-0fd8-4bfc-8b97-5166b8b33fe7
DEVICE=ens33
ONBOOT=yes
IPADDR=192.168.8.21
GATEWAY=192.168.8.2
NETMASK=255.255.255.0
DNS1=223.5.5.5
DNS2=223.6.6.6
####3、重新network服务
[root@rancher ~]# systemctl restart network.service
[root@rancher ~]# systemctl status network.service

1.2 设置主机名

###1、查看当前hostname
[root@rancher ~]# hostname
rancher
###2、用命令修改
[root@rancher ~]# hostnamectl set-hostname recketmq
###3、设置hosts。根据上文的ip和hostname如下设置
[root@rancher ~]# vim /etc/hosts
192.168.8.21 rocketmq
###4、重启主机
[root@rancher ~]# reboot
###5、检查是否设置成功
[root@rocketmq ~]# hostname
rocketmq
[root@rocketmq ~]# 
[root@rocketmq ~]# ping rocketmq
PING rocketmq (192.168.8.21) 56(84) bytes of data.
64 bytes from rocketmq (192.168.8.21): icmp_seq=1 ttl=64 time=0.063 ms

1.3 关闭防火墙

####1、查看防火墙状态
[root@rocketmq ~]# systemctl status firewalld.service
####2、关闭防火墙
[root@rocketmq ~]# systemctl stop firewalld.service
####3、关闭防火墙开机自启动
[root@rocketmq ~]# systemctl disable firewalld.service
####4、查看防火墙状态
[root@rocketmq ~]# systemctl status firewalld.service

1.3.2 设置防火墙端口

http://www.fcors.com/%e6%8a%80%e6%9c%af%e4%b8%8e%e6%a1%86%e6%9e%b6/centos-firewalld-service%e9%98%b2%e7%81%ab%e5%a2%99/

1.4 关闭selinux

###1、查看状态
[root@rocketmq ~]# getenforce
Disabled
###2、设置禁用
[root@rocketmq ~]# vim /etc/sysconfig/selinux
selinux=disabled
####3、查看状态
[root@rocketmq ~]# getenforce

1.5 主机时间同步及安装常用工具

###1、切换到阿里云yum源
[root@rocketmq ~]# mkdir /etc/yum.repos.d/repo_bak && mv /etc/yum.repos.d/CentOS* /etc/yum.repos.d/repo_bak
[root@rocketmq ~]# curl -o /etc/yum.repos.d/CentOS-7-ali.repo http://mirrors.aliyun.com/repo/Centos-7.repo
[root@rocketmq ~]# yum clean cache
[root@rocketmq ~]# yum makecache
[root@rocketmq ~]# yum repolist
###2、安装常用的软件
[root@rocketmq ~]# yum install  vim iotop bc gcc gcc-c++ glibc glibc-devel pcre \
pcre-devel openssl  openssl-devel zip unzip zlib-devel  net-tools \
lrzsz tree ntpdate telnet lsof tcpdump wget libevent libevent-devel \
bc  systemd-devel bash-completion traceroute \
bridge-utils -y
###3、时钟同步
[root@rocketmq ~]# ntpdate ntp1.aliyun.com
 9 Aug 09:48:33 ntpdate[1734]: step time server 120.25.115.20 offset -86399.130435 sec

1.6 配置免密

1.6.1 新建root权限用户

[root@rocketmq ~]# adduser fox
[root@rocketmq ~]# passwd fox

1.6.2 授权

####1、编辑文件:/ 进行vim 搜索
[root@rocketmq ~]# sudo vim /etc/sudoers
#修改文件内容
## Allow root to run any commands anywhere 
root    ALL=(ALL)       ALL
fox  ALL=(ALL)       ALL #将新用户添加再这里
###2、保存，退出

1.6.3 修改配置文件

[root@rocketmq ~]# vim /etc/ssh/sshd_config
####1、禁止root登录
PermitRootLogin yes
#修改为
PermitRootLogin no
###2、禁止使用密码登录,注释掉下面这行，或者将yes改为no
#PasswordAuthentication yes 
PasswordAuthentication no
###3、在文件末尾新增
RSAAuthentication yes
PubkeyAuthentication yes

!!!不要关闭这个页面，新开一个ssh连接，使用新用户登录。!!!

####1、切换用户
[fox@rocketmq ~]$ su - fox
Password: 
Last login: Tue Aug  9 11:13:18 CST 2022 on pts/0
[fox@rocketmq ~]$ 

1.6.4 生成证书并配置

####生成证书
[fox@rocketmq ~]$ ssh-keygen -t rsa 
Generating public/private rsa key pair.
Enter file in which to save the key (/home/fox/.ssh/id_rsa): 
Created directory '/home/fox/.ssh'.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/fox/.ssh/id_rsa.
Your public key has been saved in /home/fox/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:bC3/tDUS9qbDwT+pvY9myq9L/rvEYKuDbY30XzDfBCI fox@rocketmq
The key's randomart image is:
+---[RSA 2048]----+
|                 |
|                 |
|          E . .  |
|       . . . . . |
|        S ..= o .|
|       . o.oo* =.|
|         +.==oB.+|
|        . =B=O*+ |
|         ...@%X*.|
+----[SHA256]-----+
[fox@rocketmq ~]$
###把id_rsa导出
[fox@rocketmq .ssh]$ ls
authorized_keys  id_rsa  id_rsa.pub

1.6.5 服务安装公钥

[fox@rocketmq ~]$ cd /home/fox/.ssh/
[fox@rocketmq .ssh]$ cat id_rsa.pub >> authorized_keys
[fox@rocketmq .ssh]$ chmod 600 authorized_keys
###只要700的时候，sshd才能读到 
[fox@rocketmq .ssh]$  chmod 700 ~/.ssh

1.6.6 重启SSH服务

[fox@rocketmq .ssh]$ service sshd restart

1.6.7使用Xshell登录验证

然后选择用户密钥登录