Set up passwordless authentication in Ansible between the control node and managed nodes (Linux and Windows)

🔹 Linux Managed Node (SSH Key Authentication)

Ansible uses SSH to communicate with Linux hosts. You can enable passwordless authentication using SSH keys.

 
✅ Step 1: Generate SSH Key on the Control Node
          Run the following command on your Ansible control node (Ubuntu):

    ssh-keygen -t rsa -b 4096

            Note: Press Enter for default options.
            This creates keys in ~/.ssh/id_rsa (private key) and ~/.ssh/id_rsa.pub (public key).

 
✅ Step 2: Copy SSH Key to the Managed Node

Use ssh-copy-id to copy the key to your Linux managed node (replace with your actual username and IP):

ssh-copy-id -i ~/.ssh/id_rsa.pub user@192.168.1.100 

           This will add the public key to the remote user's ~/.ssh/authorized_keys file.

 
If ssh-copy-id is not available, manually copy the key: 

cat ~/.ssh/id_rsa.pub | ssh user@192.168.1.100 "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"

✅ Step 3: Test SSH Login Without Password

On your Ansible control node, run:

ssh user@192.168.1.100

If you can log in without entering a password, SSH key authentication is working.

 
✅ Step 4: Configure Ansible Inventory

Edit your inventory file (inventory.ini):

[linux]

192.168.1.100

 ansible_user=user 

 ansible_ssh_private_key_file=~/.ssh/id_rsa

Now, test the Ansible connection:

ansible linux -m ping -i inventory.ini

If successful, it should return:

192.168.1.100 | SUCCESS => {

                        "ping": "pong"
                           }


🔹 Windows Managed Node (WinRM with Kerberos or CredSSP)

Since Windows does not use SSH, you need to set up WinRM with Kerberos or CredSSP for passwordless authentication.
✅ Step 1: Install Required Libraries on Ansible Control Node

Run the following:

pip install pywinrm kerberos requests-kerberos requests-credssp

✅ Step 2: Configure WinRM on the Windows Managed Node

Open PowerShell (as Administrator) on Windows and run:

winrm quickconfig -q

          winrm set winrm/config/service '@{AllowUnencrypted="true"}'

          winrm set winrm/config/service/auth '@{Basic="true"}'

For Kerberos authentication, set:

winrm set winrm/config/service/auth '@{Kerberos="true"}'

For CredSSP authentication, enable it:

Enable-WSManCredSSP -Role Server

✅ Step 3: Configure Ansible Inventory

Edit your inventory file (inventory.ini):

[windows]

          192.168.1.82

                    [windows:vars]
                    ansible_user=Administrator

                    ansible_password=YourPassword123!
                    ansible_connection=winrm
                    ansible_winrm_transport=credssp
                    ansible_winrm_server_cert_validation=ignore


✅ Step 4: Test Ansible Connection to Windows

Run:

ansible windows -m win_ping -i inventory.ini

 Expected Output:

192.168.1.82 | SUCCESS => {

            "ping": "pong"

            }