Ansible reboot Linux machine or server with playbooks

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Ubuntu Linux 16.04 / 18.04 / 20.04 LTS CentOS Linux 7/8 Debian Linux 9.x RHEL 7.x/8.x SUSE 12.x/15.x FreeBSD OpenBSD

Prerequisite

I need to reboot the VM or bare metal Linux machine/server using Ansible and wait for it to come back, but it does not work with playbook as descried here. How to reboot Linux server with Ansible? How do I reboot and wait for reboot to complete in Ansible playbook for multiple Linux servers?You can reboot a Linux or Unix based machine, wait for it to go down (say for kernel update), come back up, and respond to commands. You can use either command or shell module to reboot the Linux server when kernel updated. However, now we have a reboot module to reboot a machine using Ansible.I tested this module with:

Please note that you must have Ansible version 2.7 or above to work with the reboot module:

$ ansible --version



$ sudo apt update ## Debian or Ubuntu box ##

$ sudo yum update ## RHEL/CentOS 7 ##

Ansible reboot Linux machine or server with playbooks

If not using Ansible version 2.7, try to update it using the dnf command/ yum command apt-get command as per your Linux distro version:

The syntax is pretty simple to do reboot:

- name: Reboot the machine with all defaults using Ansible reboot: - name: Reboot the machine with all defaults using Ansible reboot:

Here is a sample hosts file displayed using the cat command:

[ all:vars ] k_ver = "linux-image-4.15.0-36-generic" ansible_user = ' { { my_c_user } } ' ansible_become = yes ansible_become_method = sudo ansible_become_pass = ' { { my_c_sudo_pass } } ' [ legacy ] do-de.public [ cluster ] ln.cbz01 ln.cbz02 ln.cbz04 ln.forum [ lxd ] ln.cbz01 ln.cbz02 ln.cbz04 do-de.public [ vpn:vars ] ansible_python_interpreter = '/usr/bin/env python3' [ vpn ] do-blr-vpn [ backup ] gcvm.backup [ nodes:children ] vpn backup cluster legacy [ isrestart:children ] backup cluster vpn [all:vars] k_ver="linux-image-4.15.0-36-generic" ansible_user='{{ my_c_user }}' ansible_become=yes ansible_become_method=sudo ansible_become_pass='{{ my_c_sudo_pass }}' [legacy] do-de.public [cluster] ln.cbz01 ln.cbz02 ln.cbz04 ln.forum [lxd] ln.cbz01 ln.cbz02 ln.cbz04 do-de.public [vpn:vars] ansible_python_interpreter='/usr/bin/env python3' [vpn] do-blr-vpn [backup] gcvm.backup [nodes:children] vpn backup cluster legacy [isrestart:children] backup cluster vpn

Here is my reboot.yml:

--- - hosts: isrestart become: true become_user: root tasks: - name: Rebooting the cloud server/bare metal box reboot: --- - hosts: isrestart become: true become_user: root tasks: - name: Rebooting the cloud server/bare metal box reboot:

How to use Ansible reboot module playbook to reboot the box

Now all you have to do is run playbook (see how to set and use sudo password for Ansible Vault)

$ ansible-playbook -i hosts --ask-vault-pass --extra-vars '@cluster.data.yml' reboot.yml



How to reboot a machine and set time out value

By default Ansible reboot module waits 600 seconds. You can increase value using the following syntax:

- name: Reboot a Linux machine reboot: reboot_timeout: 1800 - name: Reboot a Linux machine reboot: reboot_timeout: 1800

How to set command to run on the rebooted host and expect success from to determine the machine is ready for further tasks

By default whoami command used by ansbile. You can change it as follows:

- name: Reboot a Linux machine reboot: test_command: uptime - name: Reboot a Linux machine reboot: test_command: uptime

OR

- name: Reboot a Linux machine reboot: test_command: ping -c 4 192.168.2.254 - name: Reboot a Linux machine reboot: test_command: ping -c 4 192.168.2.254

How to set pre and post reboot delay

One can force Ansible to wait after the reboot was successful and the connection was re-established in seconds as follows:

- name: Unconditionally reboot the machine with all defaults reboot: post_reboot_delay: 180 - name: Unconditionally reboot the machine with all defaults reboot: post_reboot_delay: 180

The above is useful if you want wait for additional networking/storage or server vpn to kick in despite your connection already working. You can also set time for shutdown to wait before requesting reboot:

- name: Unconditionally reboot the machine with all defaults reboot: pre_reboot_delay: 180 - name: Unconditionally reboot the machine with all defaults reboot: pre_reboot_delay: 180

View reboot log history on the Linux server

Let us say I am doing a conditional reboot of my Ubuntu or Debian Linux box. For instance, my Ansible playbook:

- name: Check if a reboot is needed on AWS EC2 Ubuntu/Debian based servers register: reboot_required_file stat: path=/var/run/reboot-required get_md5=no - name: Reboot the box if kernel updated/installed on EC2 reboot: msg: "Reboot initiated by Ansible for kernel updates" connect_timeout: 5 reboot_timeout: 300 pre_reboot_delay: 0 post_reboot_delay: 30 test_command: uptime when: reboot_required_file.stat.exists - name: Check if a reboot is needed on AWS EC2 Ubuntu/Debian based servers register: reboot_required_file stat: path=/var/run/reboot-required get_md5=no - name: Reboot the box if kernel updated/installed on EC2 reboot: msg: "Reboot initiated by Ansible for kernel updates" connect_timeout: 5 reboot_timeout: 300 pre_reboot_delay: 0 post_reboot_delay: 30 test_command: uptime when: reboot_required_file.stat.exists

We can search for “Reboot initiated by Ansible for kernel updates” on our server to see when my box was rebooted using the grep command/zgrep command:

$ ssh vivek@server1.cyberciti.biz

$ sudo grep 'reboot' /var/log/auth.log

$ sudo zgrep 'Reboot initiated by Ansible for kernel updates' /var/log/auth.log*

$ sudo zgrep 'reboot' /var/log/auth.log*

Sample outputs:

auth.log:Jun 9 11:06:57 ls-debian-10 systemd-logind[488]: System is rebooting (Reboot initiated by Ansible for kernel updates). auth.log.2.gz:May 27 04:55:54 ip-172-26-14-129 sudo: admin : TTY=pts/0 ; PWD=/home/admin ; USER=root ; COMMAND=/sbin/reboot

Another option is to run the last command:

$ sudo last -x "reboot"

Reboot history:

reboot system boot 4.19.0-9-amd64 Wed Jun 10 03:51 still running reboot system boot 4.19.0-9-amd64 Tue Jun 9 11:07 - 03:51 (16:43) reboot system boot 4.19.0-9-amd64 Wed May 27 04:56 - 11:06 (13+06:10) reboot system boot 4.9.0-12-amd64 Wed May 27 04:15 - 04:55 (00:40) reboot system boot 4.9.0-8-amd64 Wed May 27 04:09 - 04:14 (00:05) reboot system boot 4.9.0-8-amd64 Wed May 27 04:08 - 04:09 (00:01) wtmp begins Wed May 27 04:08:01 2020

See “How To Find Out Last System Linux Reboot Time and Date Command” for more information

Conclusion

You just learned how to reboot Linux/Unix box and wait for reboot to complete in Ansible playbook. For more info see this page here.



2 of 2 in the Ansible Reboot a Machine/Server Tutorial series. Keep reading the rest of the series: Ansible reboot a Debian/Ubuntu Linux for kernel update and wait for it Ansible reboot Linux machine or server with playbooks This entry isofin theseries. Keep reading the rest of the series: