This repository contains the mirsg.xnat
Ansible Collection. This collection can be used for deploying
XNAT in a dual-server setup.
Ansible is a free automation tool that can be used to configure servers without the need to install any agents or management servers.
You can run the Ansible playbooks on any machine that has the necessary dependencies installed. Ansible will use SSH to connect to the remote servers and perform the installation. Once deployed, the same playbooks can be used to modify or update the installation.
-
The
install_xnat
playbook deploys a dual server XNAT setup. One server -
will run the XNAT web server, and the other will run the backend PostgreSQL database server.
-
Optionally, a third server can be used to run the Container Service.
-
The roles and playbooks in this repository are developed for and tested on servers running Centos 7. Other OS versions may require modifications to the playbooks, roles, and variables.
Before using this collection and its playbooks, you must install the necessary Ansible collections and roles.
You can install this collection using the ansible-galaxy
command-line tool:
ansible-galaxy collection install https://github.com/UCL-MIRSG/ansible-collection-xnat.git
You can also include it in a requirements.yml
file and install it via
ansible-galaxy collection install -r requirements.yml
using the format:
collections:
- name: mirsg.xnat
source: https://github.com/UCL-MIRSG/ansible-collection-xnat.git
type: git
version: main
We use Ansible Molecule and its Docker plugin to test this collection and its roles and playbooks.
If you would like to run the tests locally you will need to:
- clone this repository
- install Ansible Molecule and other test requirements
- run the tests using Molecule
To test a collection, Molecule requires that it is in the path
ansible_collections/<namespace>/<collection name>
. This means when you clone this repository you
must ensure it is in the path ansible_collections/mirsg/xnat
. The simplest way to do this is:
git clone git@github.com:UCL-MIRSG/ansible-collection-xnat.git ansible_collections/mirsg/xnat
Before running the tests you'll need to install Molecule, the Docker plugin, and the Python Docker
Engine API using pip
:
python -m pip install molecule 'molecule-plugins[docker]' docker
Molecue 6.0 requires that the test configuration is not in the top-level directory of the
collection. To support running the tests with Molecule 6, the Molecule configuration is in
ansible_collections/mirsg/xnat/tests
. To run the tests you must be in this directory:
cd ansible_collections/mirsg/xnat
This collection is tested using two different Molecule scenarios - one for CentOS 7 and one for Rocky 9.
To run the tests on CentOS 7:
molecule test -s centos7
This command will:
- install the required Ansible roles and collections
- create CentOS 7 containers for the web and database servers
- run the
playbooks/install_xnat.yml
playbook to deploy XNAT on these containers - run
playbooks/install_xnat.yml
to check it is idempotent - destroy the CentOS 7 containers
To run the tests on Rocky 9:
molecule test -s rocky9
If the XNAT deployment fails at any stage during the test, the containers are immediately destroyed.
This is due to the pre-defined sequence of actions the Molecule take when the molecule test
command is invoked.
If you would like to be able to access the containers or the XNAT web interface, you should instead
use the molecule converge
command. To deploy XNAT on CentOS 7:
molecule converge -s centos7
This will install necessary Ansible roles and collections, create the containers, and run the
playbooks/install_xnat.yml
playbook. If the deployment fails, the containers are not destroyed.
Once the command has finished running, you can access the containers using their names defined in the scenario. To access the web container:
docker exec -it xnat_web /bin/bash
And to access the database container:
docker exec -it xnat_db /bin/bash
Once XNAT has been deployed on the containers, the XNAT web interface will be exposed on port 8080
of your localhost. To view the XNAT web interface go to http://localhost:8080/
in your web
browser.
If you use the molecule converge
command, you must remember to destroy the instances yourself:
molecule destroy -s centos7
When a PR that modifies any playbook or role is opened, the changes are tested by deploying XNAT using GitHub Actions. The integration tests will deploy XNAT on both CentOS 7 and Rocky 9.
The simplest way to deploy a test instance of XNAT is to use Ansible Molecule. Follow the above steps to install Molecule and deploy the test setup.
See the architecture notes for a description of the components and services that are configured for the XNAT deployment.
- The playbook will not remove existing IP ranges from the firewalls. If you remove an IP range from the configuration you also need to manually remove it on the servers.
This repo has pre-commit
hooks enabled, for instructions see https://github.com/UCL-MIRSG/.github/tree/main/precommit.
This collection is licensed and distributed under the BSD 3-Clause License.
This role was created by the Medical Imaging Research Software Group at UCL.