dnf -y upgrade
dnf -y install epel-release

dnf install -y bzip2 tree psmisc \
telnet wget rsync vim-enhanced \
net-tools bind-utils

timedatectl set-timezone Asia/Shanghai	
dnf install -y langpacks-en glibc-langpack-en
localectl set-locale LANG=en_US.UTF-8

cat >> /etc/environment <<EOF
LC_ALL=en_US.UTF-8
LANG=en_US.UTF-8
LC_CTYPE=UTF-8
EOF

cat >> /etc/profile.d/history.sh <<EOF
# Administrator specific aliases and functions for system security
export HISTSIZE=10000
export HISTFILESIZE=10000
export HISTTIMEFORMAT="%Y-%m-%d %H:%M:%S "
export TIME_STYLE=long-iso
EOF
source /etc/profile.d/history.sh

cp /etc/selinux/config{,.original}
sed -i "s/SELINUX=enforcing/SELINUX=disabled/" /etc/selinux/config
setenforce Permissive

cat >> /etc/sysctl.conf <<EOF

# Netkiller
net.ipv4.ip_local_port_range = 1025 65500
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_keepalive_time = 1800
net.core.netdev_max_backlog=3000
net.ipv4.tcp_max_syn_backlog = 1024
net.ipv4.tcp_max_tw_buckets = 4096
net.core.somaxconn = 1024

# TCP BBR
net.core.default_qdisc=fq
net.ipv4.tcp_congestion_control=bbr
EOF

sysctl -p

cat > /etc/security/limits.d/20-nofile.conf <<EOF

* soft nofile 65535
* hard nofile 65535

EOF

