refresh_ftp_users.sh

#!/bin/bash
# example : refresh_ftp_users.sh -t ftp
# This script is used to refresh the ftp users
# it reads the users in the "ftpusers group"
# and creates the users in the ftpusers file
# read ftp type variable form the command line with -t or --type
# if no variable is passed then set it to "ftp"

# set USERS variable from the ftpusers group
# if type equals ftps then FTP_USERFILE is /etc/vsftpd-ftps.userlist else /etc/vsftpd-ftp.userlist
FTP_USERFILE=/etc/vsftpd-ftp.userlist
if [ "$1" = "-t" ] || [ "$1" = "--type" ]; then
    if [ "$2" = "ftps" ]; then
        FTP_USERFILE=/etc/vsftpd-ftps.userlist
    fi
fi
# # if type equals ftps then SERVICE_NAME is vsftpd-ftps.service else vsftpd-ftps.service
SERVICE_NAME=vsftpd.service
if [ "$1" = "-t" ] || [ "$1" = "--type" ]; then
    if [ "$2" = "ftps" ]; then
        SERVICE_NAME=vsftpd-ftps.service
    fi
fi

# # if type equals ftps then GROUP_NAME is ftpsusers else ftpusers
GROUP_NAME=ftpusers
if [ "$1" = "-t" ] || [ "$1" = "--type" ]; then
    if [ "$2" = "ftps" ]; then
        GROUP_NAME=ftpsusers
    fi
fi
NEED_TO_RESTART=0
USERS=$(cat /etc/group | grep $GROUP_NAME | cut -d: -f4)
# split USERS by comma
USERS=($(echo $USERS | tr "," "\n"))

# loop through the users
for USER in ${USERS[@]}; do
    echo "Checking user $USER"
    # if user doesn't exist in the userlist file add it
    # read $USER $FTP_USERFILE file into an array
    USERS_IN_FILE=($(cat $FTP_USERFILE))
    # if user doesn't exist in the USERS_IN_FILE
    if [[ ! " ${USERS_IN_FILE[@]} " =~ " ${USER} " ]]; then
        echo "Adding user $USER"
        echo $USER >>$FTP_USERFILE
        echo "User $USER added to $FTP_USERFILE"
        mkdir -p /home/$USER/ftp
        chown nobody:nogroup /home/$USER/ftp
        chmod a-w /home/$USER/ftp
        mkdir -p /home/$USER/ftp/files
        chown $USER:$GROUP_NAME /home/$USER/ftp/files
        NEED_TO_RESTART=1
    fi
done
# check if vsftpd connection are open
# if no then restart the service
# if yes wait 2 minutes and check again
echo "Checking if vsftpd connections are open"
CONNECTIONS=$(lsof -i TCP -P -n | grep vsftpd | grep ESTABLISHED | wc -l)
if [ $NEED_TO_RESTART -eq 1 ]; then
while [ $CONNECTIONS -gt 0 ]; do
    echo "Waiting 2 minutes for vsftpd connections to close"
    sleep 120
    CONNECTIONS=$(lsof -i TCP -P -n | grep vsftpd | grep ESTABLISHED | wc -l)
done
systemctl restart $SERVICE_NAME
fi

echo "Done"