Running a shell command when a file is added to FTP on Linux Ubuntu

Question

I've recently set up a continuous integration pipeline to deploy a .NET Core application to my Linux machine living on the cloud.

My CI pipeline publishes my application, (specifically a .NET web application), zips it and then uploads by ftp.

Now, I've developed the following shell script which I will run as a service.

• This script is able to detect as soon as a file has been uploaded to my FTP folder (/home/MyName/ftp/files) by tailing the vbftp log.

• The script then stops the service running the actual web application, taking the site temporarily offline.

• The existing site is then backed up.

• We then unzip the newly uploaded file to the location where the web app lives.(/var/www/ MyProject).

• The newly uploaded file is deleted and the service restarted.

Below are the entire contents of the shell script

#!/bin/sh

tail -F /var/log/vsftpd.log | while read line; do
  if echo "$line" | grep -q 'OK UPLOAD:'; then
    filename=$(echo "$line" | cut -d, -f2)
    if [ "$ filename" == "MyProject" ]; then
     # Stop site service 
     service MyProject stop 
     # Make backup of existing files 
     sudo zip -r /var/backups/site/$(date +%F)_MyProject /var/www/MyProject 
     # unzip the newly received files 
     # (-o to overwrite only the files which have changed) 
     sudo unzip -o /home/MyName/ftp/files/MyProject.zip -d /var/www/MyProject
     # Remove uploaded zip  
     sudo rm /home/MyName/ftp/files/MyProject.zip 
     #Restart service 
     service MyProject start 
  fi
done

I'm somewhat new to Linux and shell and would love some feedback on the script I've thus far produced above.

Answer 1

[ x == y ] is not strictly-conforming POSIX sh. Use [ x = y ] instead.

Instead of using /home/MyName, you may consider using the environment variable ${HOME}.

I think you made a typo in "$ filename". Use "$filename" instead.

Good job on the commenting and indentation.