The Tomcat Cloud Images already include an SFTP server running (
/usr/lib/openssh/sftp-server) on port 22. You should be able to connect through FileZilla to your VM through SFTP. However, in order to use a FTP server, you need to install it and open the port 21. You can install using the commands below:
sudo apt-get upate && sudo apt-get install -y vsftpd
Once installed, you need to configure the server by editing the configuration file
Regarding the issue:
Connection closed without indication.
Did the error appeared after trying to fetch a file to your Tomcat server? If so, what directory where you trying to locate the file and what permissions does the directory have?