eychain for SSH with Hostname Installation

Keychain is a manager for OpenSSH, ssh.com, Sun SSH and GnuPG agents. It acts as a front-end to the agents, allowing you to easily have one long-running agent process per system, rather than per login session. This dramatically reduces the number of times you need to enter your passphrase from once per new login session to once every time your local machine is rebooted.

Install Keychain

rpm -Uvh http://packages.psychotic.ninja/7/base/x86_64/RPMS/psychotic-release-1.0.0-1.el7.psychotic.noarch.rpm
yum --enablerepo=psychotic install keychain.

Add a new user 

adduser happy

Log on to your new user

su happy

CREATE SSH KEY

Kindly following this article Step2 to create your pair of the keys.
We are strongly recommended that using a praphase for you secret keys.

And now we use below command at your server for transfer key to the client machine.

ssh-copy-id -i ~/.ssh/id_rsa user@123.123.213.123
Then enter the password and you will see something like below:

Number of key(s) added: 1

Now try logging into the machine, with: “ssh ‘user@123.123.213.123’”
and check to make sure that only the key(s) you wanted were added.

With using the highlighted text of ssh on your server, you may need to enter paraphase every single time to remote access to your client.

Log off from the client machine and log in back to the root user.

Grant sudo permission for new user

vi /etc/sudoer
Add this under root
happy ALL=(ALL) ALL

Configure keychain for the new user

cd /home/happy/
vi .bash_profile
Insert these:
### START-Keychain ###
# Let  re-use ssh-agent and/or gpg-agent between logins
/usr/bin/keychain $HOME/.ssh/id_rsa
source $HOME/.keychain/$HOSTNAME-sh
### End-Keychain ###

Take effect for your configuration

source .bash_profile
*you will ask to key in your paraphase once*

We are done for the keychain. Next , we need to configure some setting to access the client machine with hostname.

configure to ssh hostname without port and ip needed.

vim /home/happy/.ssh/config

Host webclient
HostName 192.168.0.222
Port 22299
User happy

ssh to other server

ssh webclient

EXAMPLE:
[happy@monitor .ssh]$ ssh webclient
Last login: Wed Sep 6 16:14:15 2017 from 192.168.0.221
[happy@webclient ~]$