Configuring SSH & Hostname on Virtual Box VM

ssh_on_vbox_mv.sh

#!/bin/bash
# **************** CONFIGURATION FOR LOGGING INTO VM FROM HOST VIA SSH ******************
#
#         Download and execute this script on your VM, not your host machine
#
# Pre-req:  
# - Ensure you have openssh-server installed on the VM.
# - Go to File-> Host Network Manager -> Create.  DO NOT enable `DHCP Server`.
#
# In your VM's settings, go to Network tab, add a 2nd network adapter and do the following:
#   - set `Attached to` as `Host-only adapter`
#   - set `Name` to the profile you created in Network Manager (for example, vboxnet0)
#   - set `Promisuous Mode` to `Allow VMs`
# On network Adapter 1, set up port forwarding:
#     Name    Protocol   Host IP    Host Port   Guest IP   Guest Port                                            
#     ----  ----------    --------   ---------   --------   ----------
#     ssh       TCP                   3022                      22
#
# To SSH into the VM via port #, ssh -vvvv <username>@localhost -p 3022.
#  
# ***************************************************************************************
set -o nounset                        # unset variables are errors

SCRIPTVERSION="2019.01.25-Debian"
SCRIPTNAME="ssh_on_vbox_mv.sh"
SCRIPTFULLNAME="$0"

NEWHOSTNAME="$HOSTNAME-02"    
NEWIP='192.168.56.101/24'  

echoerror() { printf "\033[1;31m * ERROR\033[0m: %s\\n" "$@" 1>&2; }

usage() {
  cat << EOT
    Usage :  ${SCRIPTNAME} [options] 

    Options:
      -h  Display this message
      -v  Display script version
      -n  hostname desired for the VM.  Default will be current name, $HOSTNAME-02
      -i  Static IP address assigned.  Default is 192.168.56.101.
EOT
}   # ----------  end of function usage  ----------

while getopts ':hvn:i:' opt
do
  case "${opt}" in

    h )  usage; exit 0                                  ;;
    v )  echo "$0 -- Version $SCRIPTVERSION"; exit 0  ;;    
    n )  NEWHOSTNAME=$OPTARG                            ;;   
    i )  NEWIP=$OPTARG                                  ;;

    \?)  echo
          echoerror "Option does not exist : $OPTARG"
          usage
          exit 1
        ;;

  esac    # --- end of case ---
done
shift $((OPTIND-1))      

# What you'll need to do to get your VMs to see each other if you have Netplan.
sudo bash -c "rm /etc/netplan/custom-vbox-init.yaml"
sudo bash -c "echo 'network:
  ethernets:
      enp0s3:
          addresses: []
          dhcp4: true
          optional: true
      enp0s8:
          addresses: [$NEWIP/24]
          dhcp4: no
          dhcp6: no
          nameservers:
            addresses: [8.8.8.8, 8.8.4.4]
  version: 2' >> /etc/netplan/custom-vbox-init.yaml"
  
sudo bash -c "netplan apply custom-vbox-init.yaml"
  
sudo bash -c "rm /etc/hostname"
sudo bash -c "echo '$NEWHOSTNAME' >> /etc/hostname"
sudo bash -c "echo '127.0.0.1  $NEWHOSTNAME' >> /etc/hosts"
sudo bash -c "ufw allow ssh  && ufw enable"

echo "$SCRIPTFULLNAME ($SCRIPTVERSION) complete.  Rebooting server in 5 seconds."
echo "If host name did not change after reboot, verify 'preserve_hostname' is set to 'true' in /etc/cloud/cloud.cfg."

sleep 5s
sudo bash -c "reboot now"