Ubuntu 系统初始化配置

系统配置

1. 删除自带的工具

   # 彻底删除 snap
   apt remove snapd --purge
   
   # 删除云功能和自动升级功能
   apt remove unattended-upgrades cloud-init
   
   # 清理相关依赖
   apt install -f && apt autoremove

2. 关闭防火墙

   systemctl disable --now ufw
   
   # 或者配置放行端口
   ufw allow 22/tcp
   ufw allow 80/tcp
   ufw allow 443/tcp

3. 配置时间同步

   # 配置NTP同步地址为`ntp.aliyun.com`
   sed -i "s@^#NTP=.*@NTP=ntp.aliyun.com@" /etc/systemd/timesyncd.conf
   
   # 设置时区以及重启服务
   timedatectl set-timezone Asia/Shanghai
   timedatectl set-ntp off
   timedatectl set-ntp on
   systemctl daemon-reload
   systemctl restart systemd-timesyncd

4. 优化 ssh 连接，提高连接速度

   sudo sed -i 's/^GSSAPIAuthentication yes$/GSSAPIAuthentication no/' /etc/ssh/sshd_config
   sudo sed -i 's/^#UseDNS yes/UseDNS no/' /etc/ssh/sshd_config
   sudo systemctl restart sshd.service

5. 更换软件源为清华源

   # 备份原文件, 在 Ubuntu 24.04 之前，Ubuntu 的软件源配置文件使用传统的 One-Line-Style，路径为 /etc/apt/sources.list；从 Ubuntu 24.04 开始，Ubuntu 的软件源配置文件变更为 DEB822 格式，路径为 /etc/apt/sources.list.d/ubuntu.sources
   cp /etc/apt/sources.list /etc/apt/sources.list.bak
   
   # 更改源文件配置
   cat > /etc/apt/sources.list <<EOF
   # 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
   deb https://mirrors4.tuna.tsinghua.edu.cn/ubuntu/ jammy main restricted universe multiverse
   # deb-src https://mirrors4.tuna.tsinghua.edu.cn/ubuntu/ jammy main restricted universe multiverse
   deb https://mirrors4.tuna.tsinghua.edu.cn/ubuntu/ jammy-updates main restricted universe multiverse
   # deb-src https://mirrors4.tuna.tsinghua.edu.cn/ubuntu/ jammy-updates main restricted universe multiverse
   deb https://mirrors4.tuna.tsinghua.edu.cn/ubuntu/ jammy-backports main restricted universe multiverse
   # deb-src https://mirrors4.tuna.tsinghua.edu.cn/ubuntu/ jammy-backports main restricted universe multiverse
   
   deb http://security.ubuntu.com/ubuntu/ jammy-security main restricted universe multiverse
   # deb-src http://security.ubuntu.com/ubuntu/ jammy-security main restricted universe multiverse
   
   # 预发布软件源，不建议启用
   # deb https://mirrors4.tuna.tsinghua.edu.cn/ubuntu/ jammy-proposed main restricted universe multiverse
   # # deb-src https://mirrors4.tuna.tsinghua.edu.cn/ubuntu/ jammy-proposed main restricted universe multiverse
   EOF
   
   # 更新系统
   apt clean
   apt update && apt upgrade -y

6. 安装常用软件包(可选)

   sudo apt-get install -y net-tools openssl network-manager lrzsz bash-completion curl unzip vim

7. 开启root账号(选配)

   # 1. 设置root账号密码
   sudo passwd root
   # 2. 开启ssh允许root账号使用密码登录
   sudo vim /etc/ssh/sshd_config
   # 将# PermitRootLogin prohibit-password行 改为 PermitRootLogin yes
   PermitRootLogin yes

8. 优化开机提示 A start job is running for Wait for Network to be Configured

   vi /lib/systemd/system/systemd-networkd-wait-online.service
   # 修改 ExecStart 配置
   ExecStart=/lib/systemd/systemd-networkd-wait-online --timeout=3

9. 优化服务响应超时时间

   vi /etc/systemd/system.conf
   # 修改
   DefaultTimeoutStartSec=10s
   DefaultTimeoutStopSec=10s

10. 优化shell登录的欢迎信息

    cd /etc/update-motd.d/
    chmod -x *
    
    # 仅显示系统状态信息
    chmod +x 00-header 50-landscape-sysinfo

11. 自定义配置文件

    cat > /etc/profile.d/custom_profile.sh << EOF
    HISTSIZE=10000
    HISTTIMEFORMAT="%F %T \$(whoami) "
    
    alias l='ls -AFhlt --color=auto'
    alias lh='l | head'
    alias ll='ls -l --color=auto'
    alias ls='ls --color=auto'
    alias vi=vim
    
    GREP_OPTIONS="--color=auto"
    alias grep='grep --color'
    alias egrep='egrep --color'
    alias fgrep='fgrep --color'
    EOF
    
    sed -i 's@^"syntax on@syntax on@' /etc/vim/vimrc

12. 修改 PS1

    [ -z "$(grep ^PS1 ~/.bashrc)" ] && echo "PS1='\${debian_chroot:+(\$debian_chroot)}\\[\\e[1;32m\\]\\u@\\h\\[\\033[00m\\]:\\[\\033[01;34m\\]\\w\\[\\033[00m\\]\\$ '" >> ~/.bashrc

13. 修改 history 显示

    [ -z "$(grep history-timestamp ~/.bashrc)" ] && echo "PROMPT_COMMAND='{ msg=\$(history 1 | { read x y; echo \$y; });user=\$(whoami); echo \$(date \"+%Y-%m-%d %H:%M:%S\"):\$user:\`pwd\`/:\$msg ---- \$(who am i); } >> /tmp/\`hostname\`.\`whoami\`.history-timestamp'" >> ~/.bashrc

14. 修改内核参数

    [ -z "$(grep 'fs.file-max' /etc/sysctl.conf)" ] && cat >> /etc/sysctl.conf << EOF
    fs.file-max = 1000000
    fs.inotify.max_user_instances = 8192
    net.ipv4.tcp_syncookies = 1
    net.ipv4.tcp_fin_timeout = 30
    net.ipv4.tcp_tw_reuse = 1
    net.ipv4.ip_local_port_range = 1024 65000
    net.ipv4.tcp_max_syn_backlog = 16384
    net.ipv4.tcp_max_tw_buckets = 6000
    net.ipv4.route.gc_timeout = 100
    net.ipv4.tcp_syn_retries = 1
    net.ipv4.tcp_synack_retries = 1
    net.core.somaxconn = 32768
    net.core.netdev_max_backlog = 32768
    net.ipv4.tcp_timestamps = 0
    net.ipv4.tcp_max_orphans = 32768
    EOF
    sysctl -p

15. 修改 limits 配置

    # 临时设置
    ulimit -SHn 65535
    
    # 永久设置
    sed -i '/^# End/i\* soft nofile    655350' /etc/security/limits.conf
    sed -i '/^# End/i\* hard nofile    131072' /etc/security/limits.conf
    sed -i '/^# End/i\* soft nproc    655350' /etc/security/limits.conf
    sed -i '/^# End/i\* hard nproc    655350' /etc/security/limits.conf
    sed -i '/^# End/i\* soft memlock   unlimited' /etc/security/limits.conf
    sed -i '/^# End/i\* hard memlock   unlimited' /etc/security/limits.conf

16. 修改控制台语言

    sed -i 's@^ACTIVE_CONSOLES.*@ACTIVE_CONSOLES="/dev/tty[1-2]"@' /etc/default/console-setup
    locale-gen en_US.UTF-8
    [ -d "/var/lib/locales/supported.d" ] && echo "en_US.UTF-8 UTF-8" > /var/lib/locales/supported.d/local
    cat > /etc/default/locale << EOF
    LANG=en_US.UTF-8
    LANGUAGE=en_US:en
    EOF