在虚拟机中最小化安装CentOS之后，配置网络、关闭SELinux和防火墙、配置EPEL仓库、安装常用软件、下载dotfiles。 https://github.com/liyang85/scripts-during-mage-linux-training/blob/master/01_improving/set_env_after_centos_mini_install_by_liyang.sh

set_env_after_centos_minimal_installation.sh

#!/bin/bash
#
#===== ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== 
# Filename:		set_env_after_centos_mini_install_by_liyang.sh
# Description:
# Date:			2018-01-07
# Author:		Li Yang
# Website:		https://liyang85.com
#===== ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== 

[ `id -u` -ne 0 ] && echo "Only root can run this script." && exit 1

# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====
# Part 0: Global variables
# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====

# all others variables MUST be put in related function,
# so them can be local.
osVer=`sed -r 's/.* ([0-9]+)\..*/\1/' /etc/centos-release`
red=`tput setaf 1`
green=`tput setaf 2`
reset=`tput sgr0`
separator="\n===== ===== ===== ===== ===== =====\n"

# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====
# Part 1: Network & Firewall & SELinux
# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====

# make default network interface up
upIface() {
	ifCfgDir="/etc/sysconfig/network-scripts"
	firstIf=`find "${ifCfgDir}" -name "ifcfg-*" | awk -F'-' '{print $NF | "sort"}' | head -n1`
	firstIfPath="${ifCfgDir}/ifcfg-${firstIf}"

	# backup and modify the configuration of the first interface
	cp -n "${firstIfPath}"{,.bak}
	# do NOT use double quotes enclose a variable in here-doc,
	# or the quotes will be wrote to target file literally
	cat > "${firstIfPath}" <<-EOF
		DEVICE=${firstIf}
		NAME=${firstIf}
		BOOTPROTO=dhcp
		ONBOOT=yes
		DNS1=223.5.5.5
	EOF
	echo -e "\n${firstIfPath} created."

	# restart network
	if [[ "${osVer}" -eq 6 ]]; then
		service network restart &> /dev/null
	elif [[ "${osVer}" -eq 7 ]]; then
		systemctl restart network &> /dev/null
	fi

	# determine if can access internet
	if ping -c1W3 baidu.com &> /dev/null; then
		echo "${green}You can access internet.${reset}"
	else
		echo "${red}You can NOT access internet.${reset}"
	fi
}
upIface
echo -e "${separator}"

# disable NetworkManager in CentOS 6
if [[ "${osVer}" -eq 6 ]]; then
	# output needs to be preserved
	service NetworkManager stop
	chkconfig NetworkManager off
	echo -e "${separator}"
fi

# Disable SELinux
if [[ `getenforce` != "Disabled" ]]; then
	setenforce 0
	sed -i.bak -r '/^SELINUX=/c SELINUX=disabled' /etc/selinux/config
	echo "SELinux disabled."
fi
echo -e "${separator}"

# Disable firewalld/iptables
if [[ "${osVer}" -eq 6 ]]; then
	iptables -F && service iptables save
	service iptables stop > /dev/null
	chkconfig iptables off
	echo "iptables disabled."
elif [[ "${osVer}" -eq 7 ]]; then
	iptables -F
	systemctl stop firewalld
	systemctl disable firewalld &> /dev/null
	echo "Firewalld disabled."
fi
echo -e "${separator}"

# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====
# Part 2: Yum & EPEL
# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====

# ensure autofs service is running before creating repo file
#
# use autofs to automatic mount OS installation iso
upAutofs() {
	if rpm -q autofs > /dev/null; then
		:
	else
		yum install -y autofs
	fi

	# start autofs and make it runs on boot
	if [[ "${osVer}" -eq 6 ]]; then
		service autofs start
		chkconfig autofs on
	elif [[ "${osVer}" -eq 7 ]]; then
		systemctl start autofs \
			&& echo -e "\nAutofs started."
		systemctl enable autofs &> /dev/null
	fi
}
upAutofs
echo -e "${separator}"

makeRepos() {
	repoDir="/etc/yum.repos.d"
	repoBakDir="${repoDir}/repo_backups"

	# backup CentOS shipped repos
	mkdir "${repoBakDir}"
	find "${repoDir}" -maxdepth 1 -name "*.repo" \
		-exec mv {} "${repoBakDir}" \;
	echo "Original repo files backuped."

	# create the Base repo based on official iso
	tab=$'\t'
	cat > "${repoDir}/base.repo" <<-EOF
		[Base]
		name=Base repo based on official iso
		baseurl=file:///misc/cd
		${tab}https://mirrors.aliyun.com/centos/\$releasever/os/\$basearch
		failovermethod=priority
		gpgcheck=0
	EOF
	echo "base.repo created."

	# create EPEL repo
	cat > "${repoDir}/epel.repo" <<-EOF
		[EPEL]
		name=EPEL from Aliyun
		baseurl=https://mirrors.aliyun.com/epel/\$releasever/\$basearch
		gpgcheck=0
	EOF
	echo "epel.repo created."
}
makeRepos
echo -e "${separator}"

# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====
# Part 3: Must-have packages
# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====

yum clean all

yum groupinstall -y \
	"base" \
	"development tools" \
	"debugging tools" \
	"compatibility libraries" \
	"network file system client"

# open-vm-tools: 
# 	make VMs of VMware can set time automatically after suspending,
#	and many more.
# open-vm-tools-desktop: 
# 	make better user experience for DESKTOP users.
yum install -y \
	git \
	tree \
	vim-enhanced \
	open-vm-tools

echo -e "${separator}"

# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====
# Part 4: Must-have tools which are need to download or compilation
# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====

# below dir must be added in $PATH,
# and I done this step in ~/.path which from 
# https://github.com/liyang85/dotfiles
localBin="/usr/local/bin"
[ -d "${localBin}" ] || mkdir -p "${localBin}"

# pRename
installPrename() {
	# A rename tool which supports perl regex syntax,
	# so I called it pRename.
	# this tool is different with the CentOS shipped /usr/bin/rename.
	pRenamePath="${localBin}/prename"
	mkdir "${pRenamePath}"
	git clone https://github.com/ap/rename.git "${pRenamePath}"
	ln -s "${pRenamePath}/rename" "${localBin}/rename" \
		&& echo "pRename installed."
}
installPrename
echo -e "${separator}"

# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====
# Part 5: dotfiles under $HOME
# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====

cd
git clone https://github.com/liyang85/dotfiles.git
bash ${HOME}/dotfiles/bootstrap.sh
echo -e "${separator}"

# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====
# Part 6: settings for particular server or client
# ===== ===== ===== ===== ===== ===== ===== ===== ===== ===== =====

# sshd
modSshd() {
	sshdCfg="/etc/ssh/sshd_config"
	if [[ -f "${sshdCfg}.bak" ]]; then
		opt="-i"
	else
		opt="-i.bak"
	fi
	# Do NOT use `-n` here, or the result will remain modified lines!
	# If a line was commented, then append one;
	# If a line was not commented, then substitute it.
	# Sometimes, settings are different between CentOS 6 and 7.
	sed ${opt} -r \
		-e '/#UseDNS/a UseDNS no' \
		-e 's/(GSSAPIAuthentication )yes/\1no/' \
		${sshdCfg}
	echo "${sshdCfg} modified."
}
modSshd
echo -e "${separator}"

echo "${green}All operations finished, enjoy...${reset}"