Compute Canada ansible-cvmfs-server role

This is an example release of the Compute Canada ansible-cvmfs-server role, which is maintained elsewhere. If you are interested in using this Ansible role please let us know!

Prepare the system

It can be useful to do echo "export PYTHONUNBUFFERED=1" >> ~/.bashrc in your session to ensure that Ansible output is streamed to stdout smoothly.

Set up ansible-pull

1. Enable EPEL repository

   EPEL is required to provide a recent version of Ansible and some JSON packages.

   • sudo dnf install epel-release

2. Install Ansible

   Ansible v2.5 or higher is required. To install from EPEL:

   • sudo dnf install ansible
   • It is useful to set force_color=True under [defaults] in /etc/ansible/ansible.cfg

3. Install git

   • sudo dnf install git

Set up inventory

1. Add the hostname of the new system to the Ansible inventory file hosts in git, with membership in the appropriate groups, and additional host or group vars as needed (which are documented here).

Run ansible-pull

1. Make sure you have logged in to the server using SSH agent forwarding (ssh -A) in order to access gitlab.
2. sudo will be used by Ansible to execute the role - so do not use sudo when invoking ansible-pull. However you may need to e.g. sudo -l at this point to avoid a password prompt if applicable.
3. It is good practice to use --check and --diff first to see which changes will be applied.

   ansible-pull -U git@github.com:ComputeCanada/ansible-cvmfs-server.git --checkout=example --full -i hosts --check --diff
   

   Note: this may fail due to missing files etc., if the play has not yet completed in non-check mode to actually make changes, which is expected.
4. Run without check mode to apply all changes.

   ansible-pull -U git@github.com:ComputeCanada/ansible-cvmfs-server.git --checkout=example --full -i hosts
   

5. If you want to limit the scope of changes to a subset of tasks, use -t to run specific tagged tasks. See main.yml for the list of tags that can be specified.

Pre-requisites

Some parts of the stratum server deployment are not automated and must be done manually in order for the Ansible play to complete successfully.

1. A modification to the iptables file will be required, as described by the output of the iptables task if needed.

Testing and development

To test the Ansible role, create a branch in Git (named test in this example), and pull from there:

ansible-pull -U git@github.com:ComputeCanada/ansible-cvmfs-server.git --checkout=test --full -i hosts