rsync is very popular synchronization tool used in Linux environment. Rsync communication is clear text by default. This makes rsync vulnerable man in the middle attacks. How can we make rsync secure with ssh . In this tutorial we will look different ways to make secure with ssh

Check Ssh Connection

The first thing we will do is checking the remote ssh service. We will of course use ssh command for this. In this example the user is root and server name is poftut2 .

$ ssh root@poftut2

Copy Single File From Local To Remote Via Ssh Tunnel

The first example is about copying local single local file to remote system via ssh. We will provide -e ssh parameter to enable ssh tunelling. We will copy file named mydata.dat into the server named poftut2 with user name ismail directory /home/ismail/

$ rsync -e ssh mydata.dat ismail@poftut2:/home/ismail/

Enable PasswordlessKey Based Ssh Authentication

In order to make things simpler and work as batch we should setup passwordless key based ssh authentication. This is done by copying and setting login public key to the remote systems. First we will create ssh kek.

$ ssh-keygen

This will create a private and related public key pair in ~/.ssh/ directory. Now we will setup key based authentication with the following command. The username will be ismail and remote system is poftut2

$ ssh-copy-id ismail@poftut2

Copy Single File From Remote To Local Via Ssh Tunnel

In this example we will copy remote file named asd.pub to the local directory /root/ . . is used to specify current working directory. The local file will be named asd.pub .

$ rsync -e ssh  ismail@poftut2:/root/asd.pub .

Synchronize From Local Folder To Remote Folder

Now we need more useful examples. One of the most used situation is synchronizing local folder to the remote folder. We will synchronize from local folder to remote folder via ssh tunnel.

$ rsync -e ssh /home/ismail/  ismail@poftut2:/bak

Synchronize From Remote Folder To Local Folder

This example is the reverse version of previous example. We will synchronize from remote system to the local system.

$ rsync -e ssh   ismail@poftut2:/bak /home/ismail/

Specify Different Ssh Port

Ssh uses TCP/22 as default port. But this may not the same for some times. We may need to specify the remote ssh port explicitly. We can use -e option with ssh command like below.

$ rsync -e "ssh 2222"   ismail@poftut2:/bak /home/ismail/