Ansible User Existence check fails during prepare.yml run for NODE installation - DX NetOps

Products

• Network Observability

Issue/Introduction

The prepare.yml playbook fails during the "Ansible User Existence" check when installing the Network Observability Deployment Engine (NODE). The error occurs even if the user exists and has sudo privileges.

Symptoms:

• The installation halts at the prepare.yml run.
• The following error is visible in the console output: Ansible User Existence (deployer) : ❌ FAILED
• User verification fails on specific nodes (e.g., ####.####.####.####).

Environment

• DX NetOps 25.4 (CaaS)
• Network Observability Deployment Engine (NODE)
• Rocky Linux 8/9

Cause

The installation pre-flight check uses sshpass to validate the user, which requires password-based authentication. Many modern Linux distributions, including Rocky Linux, have PasswordAuthentication no set by default in the SSH configuration, causing the Ansible check to fail despite valid SSH keys.

Resolution

Follow these steps to enable password authentication for the installation process:

1. Log in to each target node as a user with sudo privileges.
2. Open the SSH daemon configuration file: sudo vi /etc/ssh/sshd_config
3. Locate the PasswordAuthentication directive and change it to yes: PasswordAuthentication yes
4. Save the file and restart the SSH service: sudo systemctl restart sshd
5. Rerun the prepare.yml playbook from the deployment host.
6. Once the installation is complete, you may revert the PasswordAuthentication setting to no if required by your security policy.