Deploy Example Ansible

This is an example of an automated deployment process. The key items are the following:

• Dockerfile - Builds an example image
• .gitlab-ci.yml - Contains the CI processes
• deploy.yml - The Ansible playbook. Used to tell ansible what to do
• inventory.ini - The Ansible inventory. Contains hostname(s) to run tasks on.
• modulefile.lua.jinja2 - The modulefile template. Ansible uses this to generate the module file
• host_vars/ - This directory contains the hostname variables. These variables are applied to each hostname when the playbook is run.

CI Process

The CI process is triggered whenever a new tag is created (- if: $CI_COMMIT_TAG). It could instead be whenever a new release is made, or any other desirable condition. You could even have the completion of another CI pipeline trigger this one.

Build

Build the Dockerfile and push to the registry. This requires the following CI variables set:

• DOCKER_HUB_USERNAME
• DOCKER_HUB_PASSWORD

This step is set up for DockerHub, but there is no reason it can't be another configured registry.

Deploy

This uses an SSH key to authenticate on Setonix. For information on SSH key set up for Gitlab, see the Docs. The user needs to have the public key in their .ssh directory on Setonix. For the sake of example, I have used my personal user here. For production, this should be a privileged user. The user also needs to be set for each host in their respective host_vars file.

The command run in the CI file invokes the ansible-playbook command. This runs the deploy.yml file with ansible. Each of the tasks outlined in the file are run procedureally:

• Makes the module and software directories on Setonix if they do not exist
• Loads the singularity module and pulls the image from the registry
• Creates a Lua modulefile with the new tag version (via the template file)