Ansible reboot Module: Restart Hosts and Wait for Recovery (Complete Guide)

Ansible reboot Module: Restart Hosts and Wait for Recovery (Complete Guide)

The ansible.builtin.reboot module reboot a machine and wait for it to come back. This guide covers all common use cases with practical playbook examples.

See also: Ansible sysctl Module: Manage Kernel Parameters (Complete Guide)

Basic Reboot

- name: Reboot the server
  ansible.builtin.reboot:
# Ansible automatically waits for the host to come back

Reboot with Custom Timeout

- name: Reboot with extended timeout
  ansible.builtin.reboot:
    reboot_timeout: 600    # Wait up to 10 minutes
    connect_timeout: 30    # Connection attempt timeout
    pre_reboot_delay: 5    # Wait 5 seconds before reboot
    post_reboot_delay: 30  # Wait 30 seconds after reboot before checking
    msg: "Reboot initiated by Ansible for kernel update"

See also: Ansible hostname Module: Set System Hostname on Linux (Guide)

Conditional Reboot (Kernel Update)

- name: Update kernel
  ansible.builtin.apt:
    name: linux-generic
    state: latest
    update_cache: true
  register: kernel_update
- name: Reboot if kernel was updated
  ansible.builtin.reboot:
    msg: "Kernel updated, rebooting"
  when: kernel_update.changed

Reboot and Verify Service

- name: Reboot server
  ansible.builtin.reboot:
- name: Wait for application to be ready
  ansible.builtin.uri:
    url: "http://localhost:8080/health"
    status_code: 200
  retries: 30
  delay: 5
  register: health
  until: health.status == 200

See also: Ansible on Bottlerocket: Reboot-aware Patching Workflow Complete Guide

Check if Reboot is Required

# Debian/Ubuntu
- name: Check if reboot required
  ansible.builtin.stat:
    path: /var/run/reboot-required
  register: reboot_required
- name: Reboot if required
  ansible.builtin.reboot:
  when: reboot_required.stat.exists
# RHEL/CentOS
- name: Check if reboot needed (RHEL)
  ansible.builtin.command: needs-restarting -r
  register: needs_restart
  changed_when: false
  failed_when: false
- name: Reboot if needed
  ansible.builtin.reboot:
  when: needs_restart.rc == 1

FAQ

How do I reboot a server with Ansible?

Use ansible.builtin.reboot. It reboots the host and automatically waits for SSH to become available again before continuing with the next task.

How long does Ansible wait after a reboot?

By default, Ansible waits up to 600 seconds (10 minutes) for the host to come back. Adjust with reboot_timeout. Use post_reboot_delay to add extra wait time after SSH reconnects.

How do I check if a reboot is required in Ansible?

On Debian/Ubuntu, check if /var/run/reboot-required exists with ansible.builtin.stat. On RHEL, run needs-restarting -r and check the return code.

Conclusion

The ansible.builtin.reboot module is a versatile tool for reboot a machine and wait for it to come back. Use the examples above as starting points and adapt them to your infrastructure needs.

Related Articles

• Ansible service Module: Manage Services • Ansible wait_for Module