kema-dev / Born2beRoot

42 | Virtual Machine setup and basic SysAdmin exercice

Born2beRoot

Born2beRoot is a 42 project aiming to create a virtual machine using Virtual Box.

Full subject is available here

Below is the list of required steps to set up the VM

• Download Debian 10 iso here
• Open VirtualBox
• Click "New"
• Set a name
• Select "Linux" type
• Select version "Debian (64-bit)"
• Select "Create a fixed size VDI" with ~5 Go size
• Start the VM you just created
• When prompted, select the iso you just downloaded
• Select time zone / language / keymap...
• Choose appropriate hostname <your_42_login>42
• Choose an appropriate root password, for example "Ceciestunbon42"
• Chose a login for your new user, for example <your_42_login>
• Choose an appropriate user password, for example "Ceciestunbon42"
• Select LVM encryption with separated /home folder
• Choose an appropriate disk passphrase, for example "Ceciestunbon42"
• Choose not to use http proxy
• Select softwares SSH and standard system utilities
• Install GRUB to /dev/sda
• Log in to your VM as root

Below is the list of commands used to configure the VM

• apt install sudo

• adduser root sudo

• adduser <your_42_login> sudo

• addgroup user42

• adduser <your_42_login> user42

• touch /var/log/sudo/sudolog

• apt install vim

• vim /etc/sudoers.d/sudoconf

• Type this in

    Defaults passwd_tries=3
    Defaults badpass_message="!NO! Try <password hint>"
    Defaults logfile="/var/log/sudo/sudolog"
    Defaults requiretty
    Defaults secure_path="/sur/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:/snap/bin"

• apt install ufw

• ufw enable

• ufw allow 4242

• vim /etc/login.defs

• Type this in

  :se nu
  go to line 160
  PASS_MAX_DAYS 30
  PASS_MIN_DAYS 2
  PASS_WARN_AGE 7

• apt install libpam-pwquality

• vim /etc/pam.d/common-password

• Type this in

  :se nu
  goto line 25 and add at the end of the line
  minlen=10 ucredit=-1 dcredit=-1 maxrepeat=3 reject_username difok=7 enforce_for_root

• vim /etc/ssh/sshd_config

• Type this in

  :se nu
  go to line 13 and uncomment it
  Port 4242
  go to line 32
  PermitRootLogin no

• vim /home/<your_42_login>/monitoring.sh

• Type this in

  #!/bin/bash
  echo -n "Architecture: "
  uname -a | grep Linux
  echo -n "CPU physical: "
  cat/proc/cpuinfo | grep "cpu cores" | sed 's/cpu cores : //'
  echo -n "vCPU: "
  cat /proc/cpuinfo | grep siblings | sed 's/siblings   : //'
  echo -n "Memory Usage: "
  free | grep Mem | awk '{print $3 / 1000}' | tr '\n ' ' ' && echo -n "MB / " && free | grep Mem | awk '{print $2 / 1000}' | tr '\n' ' ' && echo -n "MB (" && free | grep Mem | awk '{print $3/$2 * 100.0}' | tr '\n ' ' ' && echo "%)"
  echo -n "Disk Usage: "
  df -hBM | awk '{tot += $2} {use +=$3} END {print use "/" tot "MB {" use/tot*100 "%)"}'
  echo -n "CPU load: "
  vmstat -SM | awk 'NR ==3 {print 100-$15 "%"}'
  echo -n "Last boot: "
  last reboot | awk 'NR == 1 {print $5 " " $6 " " $7 " " $8}'
  echo -n "LVM usage: "
  if lsblk | grep lvm > /dev/null ; then
    echo "yes"
  else
    echo "no"
  fi
  echo -n "TCP connection(s): "
  cat /proc/net/tcp | wc -l | awk '{print $1-1}'
  echo -n "User log: "
  w | wc -l | awk '{print $1 - 2}'
  echo -n "Network: "
  ip addr | grep global | awk '{print $2}' | tr '\n' ' ' && echo -n "(" && ip addre | grep ether | awk '{print $2}' | tr '\n' ' ' && echo ")"
  echo -n "Sudo: "
  cat /var/log/sudo/sudolog | wc -l | tr '\n' ' ' && echo "commands"

• crontab -u root -e

• Type this in

  */10 * * * * sh /home/<your_42_login>/monitoring.sh | wall

• vim /etc/motd

• Type this in

  <your_welcome_message>

And you're done !