Ubuntu使用备忘

新机配置

1. 使能root用户会话登录

• 设置root账户密码sudo passwd root
• 允许会话登录时手动输入账户密码

root@hy:/home/work/xml# cat /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf
[Seat:*]
greeter-show-manual-login=true
user-session=ubuntu
all-guest=false

• 放开登录权限

root@hy:/home/work/xml# cat /etc/pam.d/gdm-autologin 
#%PAM-1.0
auth    requisite       pam_nologin.so
#auth   required        pam_succeed_if.so user != root quiet_success
root@hy:/home/work/xml# cat /etc/pam.d/gdm-password 
#%PAM-1.0
auth    requisite       pam_nologin.so
#auth   required        pam_succeed_if.so user != root quiet_success

• 禁掉shell报错

root@hy:/home/work/xml# cat /root/.profile 
# ~/.profile: executed by Bourne-compatible login shells.

if [ "$BASH" ]; then
  if [ -f ~/.bashrc ]; then
    . ~/.bashrc
  fi
fi

tty -s && mesg n || true

• 重启 reboot

2. 主机利用iptables NAT功能供虚机上网

• 网络拓扑

主机物理网卡：enp2s0，配置网络代理上分配的ip，作为nat对外出口。IP:192.168.31.214
主机ovs桥：vswitch0，桥接所有虚机网卡关联到主机的tap设备vnet0 vnet1。IP:192.168.0.1
root@hy:/home/work/xml# ovs-vsctl show
8ba97384-2c99-4ae7-95e6-f6991d85565e
    Bridge "vswitch0"
        Port "vnet1"
            Interface "vnet1"
        Port "vnet0"
            Interface "vnet0"
        Port "vswitch0"
            Interface "vswitch0"
                type: internal
    ovs_version: "2.10.0"
虚机网卡：客户端。IP:192.168.0.2/3

• 主机iptables配置

1）生成iptables 规则，保存到特定目录，本人保存到/etc/iptables.roles
root@hy:/home/work/xml# cat /etc/iptables.roles 
# Generated by iptables-save v1.6.1 on Sat Nov 10 19:30:57 2018
*mangle
:PREROUTING ACCEPT [5925:2996030]
:INPUT ACCEPT [5925:2996030]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [5979:842671]
:POSTROUTING ACCEPT [6088:850803]
-A POSTROUTING -o virbr0 -p udp -m udp --dport 68 -j CHECKSUM --checksum-fill
COMMIT
# Completed on Sat Nov 10 19:30:57 2018
# Generated by iptables-save v1.6.1 on Sat Nov 10 19:30:57 2018
*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [4:279]
:POSTROUTING ACCEPT [3:206]
-A POSTROUTING -o enp2s0 -j MASQUERADE
COMMIT
# Completed on Sat Nov 10 19:30:57 2018
# Generated by iptables-save v1.6.1 on Sat Nov 10 19:30:57 2018
*filter
:INPUT ACCEPT [15:1143]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [20:1471]
-A INPUT -i virbr0 -p udp -m udp --dport 53 -j ACCEPT
-A INPUT -i virbr0 -p tcp -m tcp --dport 53 -j ACCEPT
-A INPUT -i virbr0 -p udp -m udp --dport 67 -j ACCEPT
-A INPUT -i virbr0 -p tcp -m tcp --dport 67 -j ACCEPT
-A FORWARD -d 192.168.122.0/24 -o virbr0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -s 192.168.122.0/24 -i virbr0 -j ACCEPT
-A FORWARD -i virbr0 -o virbr0 -j ACCEPT
-A FORWARD -o virbr0 -j REJECT --reject-with icmp-port-unreachable
-A FORWARD -i virbr0 -j REJECT --reject-with icmp-port-unreachable
-A FORWARD -s 192.168.0.0/24 -i vswitch0 -o enp2s0 -m conntrack --ctstate NEW -j ACCEPT	
-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A OUTPUT -o virbr0 -p udp -m udp --dport 68 -j ACCEPT
COMMIT
# Completed on Sat Nov 10 19:30:57 2018
2）将iptable配置文件持久化，下次开机自启动，自动应用iptables规则进行NAT转发
root@hy:/home/work/xml# cat /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

auto vswitch0
iface vswitch0 inet static
address 192.168.0.1
netmask 255.255.255.0

pre-up iptables-restore < /etc/iptables.roles	// 开机时自动应用iptable规则

• 客户机配置

1）centos
a 添加路由默认指向主机vswitch0的ip 192.168.0.1
b 指定dns服务器ip地址
c service network restart

CentOS虚机网络配置截图

2）ubuntu
a 添加路由默认指向主机vswitch0的ip 192.168.0.1
b /etc/systemd/resolved.conf指定dns服务器ip地址
c systemctl restart systemd-resolved

Ubuntu虚机网络配置截图

3. 允许ssh root用户登录

apt-get install openssh-client
apt-get install openssh-server
root@hy:/home/work/xml# cat  /etc/ssh/sshd_config  |grep Root
PermitRootLogin yes
重启使生效
service ssh restart
测试
ssh 127.0.0.1

4. 配置搜狗输入法

• 安装fcitx输入法框架，搜狗输入法需要此框架
  
• 设置fcitx框架
  
• 重启
• 安装sougou包

dpkg -i sogoupinyin_2.2.0.0108_amd64.deb

• 添加input method
  
• 重启

5. ubuntu开启自动补全

cat /etc/bash.bashrc 
# enable bash completion in interactive shells
if ! shopt -oq posix; then
  if [ -f /usr/share/bash-completion/bash_completion ]; then
    . /usr/share/bash-completion/bash_completion
  elif [ -f /etc/bash_completion ]; then
    . /etc/bash_completion
  fi
fi

日常命令

1. 弹出光驱eject r
2. 光驱制作mkisofs -o $iso $path
3. 免密

a ssh-keygen	
b ssh-copy-id ip

4. 代码编译

a apt-get source 
b apt-get build-dep linux	// 安装编译内核需要的包
c dpkg-buildpackage 		// 源码目录运行