Add 'debian-setup.sh'

debian-setup.sh

@@ -0,0 +1,104 @@
+#!/bin/bash
+
+### configuration ###
+admin_user="newnius"
+
+
+#####################
+
+# check environment
+if [ "$EUID" -ne 0 ]; then
+  echo "[ERROR] Please run as root"
+  exit 1
+fi
+
+if ! hash apt 2>/dev/null; then
+  echo "[ERROR] Only debian is supported"
+  exit 1
+fi
+
+
+# install security updates
+apt update
+
+#uncomment as it may prompt update grub window
+#apt upgrade -y
+
+# install necessary tools
+echo "[INFO] Installing necessary tools"
+apt install -y curl vim git sudo ca-certificates apt-transport-https haveged
+
+# install ssh service
+if ! hash sshd 2>/dev/null; then
+  echo "[INFO] Installing ssh service"
+  apt install -y openssh-server openssh-client
+fi
+
+# Add admin user
+echo "[INFO] Creating admin user"
+ssh_pass=$(head /dev/urandom | tr -dc A-Za-z0-9 | head -c 32)
+
+useradd $admin_user -m -s /bin/bash
+echo $admin_user:$ssh_pass | chpasswd
+
+
+# Add to sudoers
+sed -i "/$admin_user/d" /etc/sudoers
+sed -i "/User privilege specification/a $admin_user\tALL=(ALL:ALL) ALL" /etc/sudoers
+
+
+# update root password to random and forget it
+echo "[INFO] Updating root password to random"
+pass=$(head /dev/urandom | tr -dc A-Za-z0-9 | head -c 32)
+echo root:$pass | chpasswd
+
+
+# ssh, update port, decline root ligin
+echo "[INFO] Updating ssh port"
+ssh_port=$((RANDOM%65535+10000))
+sed -i '/Port /d' /etc/ssh/sshd_config
+echo "Port $ssh_port" >> /etc/ssh/sshd_config
+
+sed -i '/^PermitRootLogin/d' /etc/ssh/sshd_config
+echo "PermitRootLogin no" >> /etc/ssh/sshd_config
+
+systemctl restart ssh
+
+# install ntpdate
+echo "[INFO] Configuring time sync service"
+apt install -y ntp ntpdate ntpstat
+
+systemctl stop ntp
+ntpdate pool.ntp.org
+systemctl start ntp
+
+
+# enable bbr, requires 4.9.0 or higher
+if [ "$(uname -r)" = "`echo -e "$(uname -r)\n4.9.0" | sort -V | head -n1`" ]; then
+  echo "[WARN] bbr is not supported on $(uname -r), skip"
+else
+  echo "[INFO] Enabling bbr"
+  sed -i '/net.core.default_qdisc/d' /etc/sysctl.conf
+  echo "net.core.default_qdisc=fq" >> /etc/sysctl.conf
+
+  sed -i '/net.ipv4.tcp_congestion_control/d' /etc/sysctl.conf
+  echo "net.ipv4.tcp_congestion_control=bbr" >> /etc/sysctl.conf
+
+  sysctl -p
+fi
+
+# Disable ipv6
+#sed -i '/net.ipv6.conf.all.disable_ipv6/d' /etc/sysctl.conf
+#echo "net.ipv6.conf.all.disable_ipv6 = 1" >> /etc/sysctl.conf
+#sysctl -p
+
+
+# output
+echo "[INFO] Setup finished"
+
+res="SSH user:\t$admin_user\n \
+SSH port:\t$ssh_port\n \
+SSH password:\t$ssh_pass\n"
+
+echo -e $res | expand --tabs=16
+