Enable Passwordless Authenication Between Linux Machine

Let’s consider linux machine as Host 1 and Host 2, we will enable passwordless authenication from host 1 to host 2

Host 1:

1. Create a new user for ansible administration & grant admin access to user

   useradd ansadmin
   
   passwd ansadmin

2. Add below lines to visudo

   visudo
   
   ansadmin ALL=(ALL) NOPASSWD: ALL

3. Using key-based authentication is advised. If you are still at learning stage use password based authentication:

   sed -ie 's/PasswordAuthentication no/PasswordAuthentication yes/' /etc/ssh/sshd_config

4. Restart sshd service

   service sshd restart

Host 2:

1. Create a new user for ansible administration & grant admin access to user

   useradd ansadmin
   
   passwd ansadmin

2. Add below lines to visudo

   visudo
   
   ansadmin ALL=(ALL) NOPASSWD: ALL

3. Using key-based authentication is advised. If you are still at learning stage use password based authentication:

   sed -ie 's/PasswordAuthentication no/PasswordAuthentication yes/' /etc/ssh/sshd_config

4. Restart sshd service

   service sshd restart

Host 1:

1. Login as a ansadmin user

   su - ansadmin

2. Generate SSH

   ssh-keygen

3. Copy keys onto Host 2

   ssh-copy-id <Host 1 IP address>