Ansible Ignore Errors: Complete Guide to Error Handling

Ansible is a powerful automation tool, but dealing with errors efficiently is crucial for maintaining smooth deployments and configurations. Whether you want to ignore certain errors, define custom failure conditions, or control how unreachable hosts are handled, Ansible provides multiple mechanisms to fine-tune error handling.

In this guide, we’ll explore different ways to handle errors in Ansible, including ignore_errors, failed_when, ignore_unreachable, any_errors_fatal, and command-line options.

1. Ignoring Errors in a Task with ignore_errors

The simplest way to ignore errors in Ansible is by using ignore_errors: yes. When this directive is added to a task, Ansible will continue executing subsequent tasks even if the current task fails.

Example: Ignoring Errors in a Task

- name: Example playbook using ignore_errors
  hosts: all
  tasks:
    - name: Run a command that might fail but ignore errors
      command: /bin/false
      ignore_errors: yes

    - name: Next task that will run regardless of the previous error
      debug:
        msg: "This task runs even though the previous one failed."

Key Takeaway: The failed task will still be marked as failed in the output, but it won’t interrupt the playbook execution.

2. Customizing Failure Conditions with failed_when

By default, Ansible considers a nonzero exit status as a failure. However, you can define custom conditions for marking a task as failed using failed_when.

Example 1: Preventing a Task from Failing

- name: Run a command but never mark it as failed
  command: /bin/false
  register: result
  failed_when: false

This ensures that the task is always marked as successful, even if the command fails.

Example 2: Failing Only on Specific Conditions

- name: Run a command and fail only on specific error text
  command: some_command
  register: result
  failed_when: "'CRITICAL ERROR' in result.stderr"

This marks the task as failed only if the output contains “CRITICAL ERROR”, giving you more granular control.

3. Ignoring Unreachable Hosts with ignore_unreachable

By default, Ansible stops execution if a host is unreachable. If you want to continue execution despite unreachable hosts, use ignore_unreachable.

Example:

- name: Ping hosts, ignoring unreachable errors
  hosts: all
  tasks:
    - name: Ping the hosts
      ping:
      ignore_unreachable: yes

Key Takeaway: This is useful when working with unreliable networks or dynamic inventories where some hosts may not always be accessible.

4. Making All Errors Fatal with any_errors_fatal

If you want to stop execution on all hosts when any host encounters an error, use any_errors_fatal.

Example:

- name: Play where any error is fatal for all hosts
  hosts: all
  any_errors_fatal: true
  tasks:
    - name: This command will abort the run on all hosts if it fails
      command: /bin/false

Useful in scenarios where consistency across hosts is critical.

5. Controlling Failure Percentage with Command-Line Options

While most error handling is done inside playbooks, you can also adjust failure handling at runtime.

Example: Allowing a Certain Percentage of Failures

ansible-playbook playbook.yml --max-fail-percentage=100

This allows failures on up to 100% of hosts without aborting the playbook.

Ansible Error-Handling Techniques

Final Thoughts

Error handling in Ansible is highly flexible, allowing you to control how failures are treated based on your specific use case. Whether you need to ignore minor errors, fail only under certain conditions, or stop execution across all hosts, these techniques will help you build robust playbooks.

By leveraging ignore_errors, failed_when, ignore_unreachable, any_errors_fatal, and command-line options, you can ensure smooth automation workflows without unexpected disruptions.

Would you like more Ansible tips? Let us know in the comments!