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Ansible Level 01 – Day 03: Configure Default SSH User for Ansible

This document explains how to modify the default Ansible configuration so that all connections to remote systems automatically use a specific SSH user. Instead of repeatedly specifying the user in inventories or command‑line flags, the configuration is defined once in the global Ansible configuration file.

Objective

Configure Ansible to automatically use the following SSH user for all remote connections:

  • Default SSH User: kirsty
  • Configuration File: /etc/ansible/ansible.cfg
  • Environment: Jump Host

The modification must be applied to the existing system configuration file rather than creating a new local configuration.

Understanding the Role of ansible.cfg

Ansible behaviour is controlled through a configuration file named ansible.cfg. This file defines default values for various runtime parameters such as:

  • Default inventory location
  • SSH connection settings
  • Module search paths
  • Logging behaviour

By defining a default remote user in this configuration, Ansible automatically uses that account whenever it connects to remote hosts.

Step 1: Identify the Active Configuration File

Verify which configuration file Ansible is currently using.

ansible --version

Example output includes a line similar to:

config file = /etc/ansible/ansible.cfg

This confirms that the system-wide configuration file is located at /etc/ansible/ansible.cfg.

Step 2: Edit the Global Configuration

Because the configuration file resides inside /etc, administrative privileges are required to modify it.

sudo vi /etc/ansible/ansible.cfg

Locate the [defaults] section near the top of the file.

Find the remote_user parameter. By default it usually appears commented out.

Example of the default configuration:

#remote_user = root

Update it so that Ansible uses kirsty as the default user.

[defaults]

remote_user = kirsty

Save and exit the file.

Step 3: Verify the Configuration

Confirm that Ansible recognizes the updated configuration.

ansible-config dump | grep REMOTE_USER

Expected output:

DEFAULT_REMOTE_USER(/etc/ansible/ansible.cfg) = kirsty

This indicates that Ansible will now automatically attempt to connect using the kirsty user unless another value overrides it.

How This Affects Ansible Execution

After the configuration change, any Ansible command such as:

ansible all -m ping

or

ansible-playbook playbook.yml

will implicitly use the SSH user kirsty for remote connections.

This eliminates the need to include the following parameters repeatedly:

-u kirsty

or defining the user inside every inventory entry.

Configuration Precedence in Ansible

Ansible determines which configuration settings to apply by checking several possible configuration locations in a fixed order. The first file found is used.

Priority order:

  1. ANSIBLE_CONFIG environment variable
  2. ./ansible.cfg in the current working directory
  3. ~/.ansible.cfg in the user home directory
  4. /etc/ansible/ansible.cfg system‑wide configuration

Because this task requires modifying /etc/ansible/ansible.cfg, the configuration applies globally for the system unless overridden by higher‑priority configuration files.

Key Outcome

The Ansible configuration has been updated so that all remote connections default to the SSH user kirsty. This simplifies playbook execution and removes the need to repeatedly define the SSH user in inventories or command-line options.