How to reboot CentOS 7 with Ansible?

Question

I\'m trying to reboot server running CentOS 7 on VirtualBox. I use this task:

- name: Restart server
  command: /sbin/reboot
  async: 0
  poll:          


        

Answer 1

At reboot time all ssh connections are closed. That's why the Ansible task fails. The ignore_errors: true or failed_when: false additions are no longer working as of Ansible 1.9.x because handling of ssh connections has changed and a closed connection now is a fatal error which can not be caught during play.

The only way I figured out how to do it is to run a local shell task which then starts a separate ssh connection, which then may fail.

- name: Rebooting
  delegate_to: localhost
  shell: ssh -S "none" {{ inventory_hostname }} sudo /usr/sbin/reboot"
  failed_when: false
  changed_when: true

Answer 2

if you're using Ansible version >=2.7, you can use reboot module as described here

The synopsis of the reboot module itself:

Reboot a machine, wait for it to go down, come back up, and respond to commands.

In a simple way, you can define a simple task like this:

    - name: reboot server
      reboot:

But you can add some params like test_command to test if your server is ready to take further tasks

    - name: reboot server
      reboot:
        test_command: whoami

Hope this helps!

Answer 3

Ansible is developing quickly and the older answers were not working for me.

I found two issues:

• The recommended way of rebooting may kill the SSH connection before Ansible finishes the task.

It is better to run: nohup bash -c "sleep 2s && shutdown -r now" &

This will launch a shell with the sleep && shutdown, but will not wait for the shell to end due to the last &. The sleep will give some time for the Ansible task to end before the reboot and the nohup will guarantee that bash doesn't get killed when the task ends.

• The wait_for module is not reliably waiting for the SSH service.

It detects the port open, probably open by systemd, but when the next task is run, SSH is still not ready.

If you're using Ansible 2.3+, wait_for_connection works reliably.

The best 'reboot and wait' in my experience (I am using Ansible 2.4) is the following:

- name: Reboot the machine
  shell: nohup bash -c "sleep 2s && shutdown -r now" &

- name: Wait for machine to come back
  wait_for_connection:
    timeout: 240
    delay: 20

I've got the nohup command from: https://github.com/keithchambers/microservices-playground/blob/master/playbooks/upgrade-packages.yml

I edited this message to:

• add krad's portability suggestion, using shutdown -r now instead of reboot
• add a delay. It is needed to avoid Ansible to execute the next step if the reboot is slow
• increase the timeout, 120s was too little for some slow BIOS.

Answer 4

Following solution works for me perfect:

- name: Restart machine
  shell: "sleep 5 && sudo shutdown -r now"
  async: 1
  poll: 0

- name: wait for ssh again available.
  wait_for_connection:
    connect_timeout: 20
    sleep: 5
    delay: 5
    timeout: 300

Sleep is required because ansible requires few second's to wrap up connection. Excelent post about this problem was written here: https://www.jeffgeerling.com/blog/2018/reboot-and-wait-reboot-complete-ansible-playbook

Answer 5

After the reboot task, you should have a local_action task that waits for the remote host to finish rebooting, otherwise, the ssh connection will be terminated and so is the playbook.

- name: Reboot server
  command: /sbin/reboot

- name: Wait for the server to finish rebooting
  sudo: no
  local_action: wait_for host="{{ inventory_hostname }}" search_regex=OpenSSH port=22 timeout=300

I also wrote a blog post about achieving a similar solution: https://oguya.github.io/linux/2015/02/22/ansible-reboot-servers/