create a new user with unique ssh key

createSSHUser.sh

function createSSHUser {
   #
   touch /root/trash 2> /dev/null
   if [  $? -ne  0  ]
   then
      echo "Must execute as root user . . . "
      echo "sudo ./createNewSSHUser.sh"
      exit 0;
   fi
   export A_NEW_USER=$1
   export NEW_USER_PWD=aptx4869
   export ADMIN=ywq
   export ADMIN_DIR=/home/${ADMIN}
   #
   echo New User is $A_NEW_USER identified by $NEW_USER_PWD
   #
   echo "Get ${A_NEW_USER} home directory .. . . . . . . . "
   export A_NEW_USER_HOME=$( grep "${A_NEW_USER}" /etc/passwd | awk -F: '{print $6}' )
   echo "New user's home directory is ${A_NEW_USER_HOME}"
   #
   if [ "XX${A_NEW_USER_HOME}" == "XX" ]; then
   #
   echo "Create a full privileges admin user ..........................."
   export PASS_HASH=$(perl -e 'print crypt($ARGV[0], "password")' "$NEW_USER_PWD")
   echo ${PASS_HASH}
   # addgroup sudo
   useradd -Ds /bin/bash
   useradd -m -p ${PASS_HASH} ${A_NEW_USER}
   #passwd -e ${A_NEW_USER}
   #
   A_NEW_USER_HOME=/home/${A_NEW_USER}
   else
   echo "The ${A_NEW_USER} user account is already configured in ${A_NEW_USER_HOME} . . . "
   fi
   #
   echo "................................................................"
   echo "Prepare for SSH tasks"
   echo "................................................................"
   #
   apt-get install -y openssh-server
   #
   export A_NEW_USER_SSH_DIR=${A_NEW_USER_HOME}/.ssh
   mkdir -p ${A_NEW_USER_SSH_DIR}
   chmod 700 ${A_NEW_USER_SSH_DIR}
   #
   pushd ${A_NEW_USER_SSH_DIR}
   #
     #
     echo "................................................................"
     echo "Generate SSH key pair for ${A_NEW_USER}"
     echo "................................................................"
     rm -f id_rsa*
     ssh-keygen -f id_rsa -t rsa -N '' -C "${A_NEW_USER}@${A_NEW_USER}.me"
     #
   #
   popd
   echo "................................................................"
   echo "Authorizing public key ......................................"
   echo "................................................................"
   cat ${A_NEW_USER_SSH_DIR}/id_rsa.pub > ${A_NEW_USER_SSH_DIR}/authorized_keys
   #
   echo "................................................................"
   echo "Assign correct ownership ......................................"
   echo "................................................................"
   chown -R ${A_NEW_USER}:${A_NEW_USER} /home/${A_NEW_USER}
   #
   #
   echo "................................................................"
   echo "Here is ${A_NEW_USER}'s private key"
   echo "................................................................"
   echo " "
   cat ${A_NEW_USER_SSH_DIR}/id_rsa
   echo "................................................................"
   echo "Backing up in ADMIN's dir"
   echo "................................................................"
   echo " "
   cp ${A_NEW_USER_SSH_DIR}/id_rsa ${ADMIN_DIR}/user_management/${A_NEW_USER}.id
   chown -R ${ADMIN}:${ADMIN} ${ADMIN_DIR}/user_management/${A_NEW_USER}.id
   echo " "
   echo " "
   echo " "
   echo Done creating new user ${A_NEW_USER}
   echo   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

   echo " "
   echo Please change password for new user ${A_NEW_USER}
   echo   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
   passwd  ${A_NEW_USER}
}