Let's imagine you have a script to set up your servers from scratch. In this case, let's call it
setup.sh and for now, it will just be a BASH script that updates a debian/ubuntu server and installs git.
Create the Setup Script
Lets create the script on our Ansible server because it needs to be local.
#!/bin/bash sudo apt update sudo apt-get dist-upgrade -y sudo apt-get install git -y
For this tutorial I have put it in
Update The Hosts File
If your starting out, then you need to create a group in your hosts file that we will run the setup script on. For this tutorial, my group is
Create the Playbook
Now we need to create the ansible playbook that will transfer that script to the remote server(s) and execute it. For this tutorial, I am calling it
- hosts: my-servers sudo: true tasks: - script: /home/stuart/scripts/setup.sh
Now run the following command to execute your script. You may or may not need to swap out the
ansible-playbook setup.yml --user=$USER
Taking It Further
If you want to ensure that your script only ever gets executed once, then you can simply tweak your playbook to be like this:
- hosts: my-servers sudo: true tasks: - script: /home/stuart/scripts/setup.sh --creates /home/stuart/installed-git.txt
You will see that we added
--creates which specifies the location of a file to check and if it exists, our script will not be executed. It does not implicitly create a blank file at that location, or pipe all the output to that location. Hence we need to update our local script to create that file so that subsequent calls will not be executed.
#!/bin/bash sudo apt update sudo apt-get dist-upgrade -y sudo apt-get install git -y # Create our file to check for in future echo "installed git!" >> /home/stuart/installed-git.txt
If we created an uninstall script, we would want that to also only executed once, and only if we have already executed the installation script. Thus we would want to check if the
installed-git.txt file exists, and only run if it doesn't. Luckily the
--removes option provides this functionality.
For this, our uninstall.yml playbook would be like so:
- hosts: my-servers sudo: true tasks: - script: /home/stuart/scripts/uninstall-git.sh --removes /home/stuart/installed-git.txt
Our local uninstall-git.sh script would be like so:
#!/bin/bash sudo apt-get remove git -y # Remove our file rm /home/stuart/installed-git.txt
Just like the
--creates option, it does not implicitly remove the file for you, it only make ansible execute the script the file already exists. Your script has to remove the file.