Python Special Methods with examples

Ansible Modules

ansible webservers -m service -a "name=httpd state=started"
ansible webservers -m ping
ansible webservers -m command -a "/sbin/reboot -t now"

Use Case(Taken From Ansible official page)

Let’s use Ansible’s command line tool to reboot all web servers in Atlanta, 10 at a time. First, let’s set up SSH-agent so it can remember our credentials:


$ ssh-agent bash
$ ssh-add ~/.ssh/id_rsa




If you don’t want to use ssh-agent and want to instead SSH with a password instead of keys, you can with --ask-pass (-k), but it’s much better to just use ssh-agent.

Now to run the command on all servers in a group, in this case, atlanta, in 10 parallel forks:


$ ansible atlanta -a "/sbin/reboot" -f 10




/usr/bin/ansible will default to running from your user account. If you do not like this behavior, pass in “-u username”. If you want to run commands as a different user, it looks like this:


$ ansible atlanta -a "/usr/bin/foo" -u username




Often you’ll not want to just do things from your user account. If you want to run commands through privilege escalation:


$ ansible atlanta -a "/usr/bin/foo" -u username --become [--ask-become-pass]




Use --ask-become-pass (-K) if you are not using a passwordless privilege escalation method (sudo/su/pfexec/doas/etc). This will interactively prompt you for the password to use. Use of a passwordless setup makes things easier to automate, but it’s not required.

It is also possible to become a user other than root using --become-user:


$ ansible atlanta -a "/usr/bin/foo" -u username --become-user otheruser [--ask-become-pass]