Accessing Remote Machines Passwordless

If you are tired of entering password everytime you ssh into your remote machine, you may want to create public-provate key pair and store your public key into your remote machine and the private key into your local machine. You can create such key pair by running the following command from your local machine -

ssh-keygen

This will create two files in your .ssh directory on your $HOME folder - one with the name id_rsa which is your private key and the other with id_ras.pub which is it’s corresponding public key

Place the contents of the public key in the $HOME/.ssh/authorized_keys of the remote machine.

Now, you should be able to connect your remote machine using -

ssh user@[ip address of the remote machine]

If you want to run a few commands after you passwordlessly connect to your remote machine, your shell script should follow the following format:

ssh user@[ip address of the remote machine] "
    mkdir ~/test;
    ls ~;
"

Note: The permissions of the files in .ssh folder for the keys and authorized_keys files, their ownership should be similar to the figure below:

And the permission of the .ssh folder itself should be 700

One helpful tip I want to live you with before ending this article is the use of config file in the ~/.ssh folder. If you are ssh-ing many different hosts and if you want to save time typing the entire name of the host you’re ssh-ing into or just don’t want to go through the hassle of remembering long names, you can add these host names into your ~/.ssh/config file in the following format:

Host api-server-node
    HostName 192.168.0.24
    User ds

Host emr-master-prod
    HostName emr-prod.example.com
    User ed

Host emr-master-stage
    HostName emr-stage.example.com
    User ed
    Port 8088

• Miscellaneous