任务一：将之前练习过的命令做出一个shell脚本一键运行（三台同理）

1.创建脚本文件

1.1用vim直接创建并编辑

vim shell.sh

1.2编写脚本内容

#!/bin/bash
set -e

# 配置参数
NETWORK_CARD="ens33"
GATEWAY="192.168.88.2"
DNS1="8.8.8.8"
BASE_IP_PREFIX="192.168.88.10"
TOTAL_NODES=3
HADOOP_PASS="123456"

# 检查root权限
[ "$(id -u)" -ne 0 ] && echo "Please run with sudo" && exit 1

# 检查参数
[ -z "$1" ] && echo "Usage: $0 <node number 1-3>" && exit 1

NODE_NUM=$1
HOSTNAME="node${NODE_NUM}"
IP_ADDR="${BASE_IP_PREFIX}${NODE_NUM}"

# 验证节点编号范围
[ "$NODE_NUM" -lt 1 ] || [ "$NODE_NUM" -gt "$TOTAL_NODES" ] && echo "Number out of range" && exit 1

echo "======================================"
echo "Start configuring $HOSTNAME ($IP_ADDR)"
echo "======================================"

# 设置主机名
echo "1. Setting hostname to $HOSTNAME..."
hostnamectl set-hostname "$HOSTNAME"
echo "127.0.0.1 $HOSTNAME localhost" >>/etc/hosts

# 配置网络
echo "2. Configuring network interface $NETWORK_CARD..."
DEV=$NETWORK_CARD
nmcli con delete "$DEV" 2>/dev/null || true
nmcli con add type ethernet ifname "$DEV" con-name "$DEV" ip4 "$IP_ADDR/24" gw4 "$GATEWAY" ipv4.dns "$DNS1" ipv4.method manual
nmcli con up "$DEV"

# 关闭防火墙和SELinux
echo "3. Disabling firewall and SELinux..."
systemctl disable --now firewalld
sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config

# 创建hadoop用户
echo "4. Creating hadoop user..."
id hadoop &>/dev/null || (useradd hadoop && echo "$HADOOP_PASS" | passwd --stdin hadoop)

# 配置SSH密钥
echo "5. Configuring SSH keys..."
[ ! -f /root/.ssh/id_rsa ] && ssh-keygen -t rsa -P "" -f /root/.ssh/id_rsa
cat /root/.ssh/id_rsa.pub >> /root/.ssh/authorized_keys
chmod 600 /root/.ssh/authorized_keys

echo "======================================"
echo "$HOSTNAME configuration completed!"
echo "IP Address: $IP_ADDR"
echo "Hostname: $HOSTNAME"
echo "Please reboot the system to apply all changes."
echo "======================================"

1.3保存脚本

1.4赋予脚本执行权限

chmod +x shell.sh

1.5运行

sudo ./shell.sh 1/2/3

1.6结果输出

1.7重启

sudo reboot

任务二：建多台VM

详见0924

任务三：在任务2的多台VM上跟任务1一样操作，然后测试免密登录

详见0917