Tutorial
How To Use Loops in Ansible Playbooks
Ansible is a modern configuration management tool that doesn’t require the use of an agent software on remote nodes, using only SSH and Python to communicate and execute commands on managed servers. This series will walk you through the main Ansible features that you can use to write playbooks for server automation. At the end, we’ll see a practical example of how to create a playbook to automate setting up a remote Nginx web server and deploy a static HTML website to it.
When automating server setup, sometimes you’ll need to repeat the execution of the same task using different values. For instance, you may need to change permissions of multiple files, or create multiple users. To avoid repeating the task several times in your playbook file, it’s better to use loops instead.
In programming, a loop allows you to repeat instructions, typically until a certain condition is met. Ansible offers different looping methods, with the loop keyword being the most recommended option for longer term compatibility.
The following example creates three different files on the /tmp location. It uses the file module within a task that implements a loop using three different values.
Create a new file called playbook-06.yml in your ansible-practice directory:
- nano ~/ansible-practice/playbook-06.yml
Then add the following lines to the new playbook file:
---
- hosts: all
tasks:
- name: creates users files
file:
path: /tmp/ansible-{{ item }}
state: touch
loop:
- sammy
- erika
- brian
Save and close the file when you’re done.
Then, run ansible-playbook with the same connection arguments from the previous examples. Again, we’re using an inventory file named inventory and a user named sammy, but you should change these values accordingly:
- ansible-playbook -i inventory playbook-06.yml -u sammy
You’ll get output like this, showing each individual item value that was used within the loop:
Output...
TASK [creates users files] ******************************************************************************
changed: [203.0.113.10] => (item=sammy)
changed: [203.0.113.10] => (item=erika)
changed: [203.0.113.10] => (item=brian)
...
For more detailed information on how to use loops when writing Ansible playbooks, please refer to the official documentation.
