CVMFS Server Setup (using Ansible)

Set up CVMFS repositories on a Stratum-0 machine, Stratum-1 (with reverse proxy) machines, forward caching proxy machines, and client machines.

The setup is based on the following documentation:

1. Official docs
2. CVMFS tutorial

Table of Contents:

• CVMFS Server Setup (using Ansible)
  • Initial Steps
    • Installation
    • Setup
  • Usage
  • Testing
    • Installation / Setup
    • Test execution

Initial Steps

Installation

Install this collection with

ansible-galaxy collection install git+https://github.com/max-fatouros/cvmfs-ansible-setup.git

Setup

1. Copy the hosts.yml file. Replace the hosts under the stratum-0, stratum-1, proxy, client, and cvmfs groups with the ones you want to use. If you would like to not use stratum-1s and/or proxies, leave the values of their host: key blank, but do not remove the stratum-1: or proxies: keys entirely. The format of this file is described in How to build your inventory. This file is also where the parameters for the setup are configured.

2. Create a copy of this ansible.cfg file.

3. With both the hosts.yml and ansible.cfg files in your working directory. Test that things are working with the command

   ansible-playbook cvmfs.setup.ping

4. Many of the ansible commands require sudo privileges on the remote machines. If you would like to disable the sudo password on the remote machines so that the playbooks in this collection can be run without a password, first run the following command, enter the sudo password for the machine which will have its sudo password removed, then press enter.

   read -s PASS

   After this, run

   ansible-playbook -l <host> -e "ansible_sudo_pass=$PASS" cvmfs.setup.remove_sudo-pass

   where <hosts> is the hostname (specified in hosts.yaml) of the machine whose sudo password we are removing.

Usage

1. Run

   ansible-playbook cvmfs.setup.all

   this is equivalent to running

   ansible-playbook cvmfs.setup.stratum_0
   ansible-playbook cvmfs.setup.stratum_1s
   ansible-playbook cvmfs.setup.proxies
   ansible-playbook cvmfs.setup.clients

   after running cvmfs.setup.all, any of the individual playbooks above can be re-run if needed. However, they all rely on cvmfs.setup.stratum_0 having been run once in order for the stratum-0 public keys to be copied over properly.

2. To ensure that the environment was set up correctly, you could try propagating a test file through all the machines. i.e. from

   stratum-0 -> stratum-1 -> proxy -> client

   By following these instructions, we can do this with the following commands

   1. On the Stratum-0

      Set an environment variable to the name of your repository.

      MY_REPO_NAME=<repo.org.tld>

      Then, run these commands¹

      cvmfs_server transaction ${MY_REPO_NAME}
      echo '#!/bin/bash' > /cvmfs/${MY_REPO_NAME}/hello.sh
      echo 'echo hello' >> /cvmfs/${MY_REPO_NAME}/hello.sh
      chmod a+x /cvmfs/${MY_REPO_NAME}/hello.sh
      cvmfs_server publish ${MY_REPO_NAME}

   2. On a Stratum-1

      Synchronize the file with²

      cvmfs_server snapshot repo.org.tld>

      again, replacing <repo.org.tld> with your cvmfs-repository name.

   3. On one of the Client machines

      Test that you can access the file with the command

      /cvmfs/<repo.org.tld>/hello.sh

      You can also run the following test commands on the client^{3 4}.

      cvmfs_config chksetup  # should return OK
      cvmfs_config stat -v <repo.org.tld>

      The output of the stat command should contain a line with the following

      Connection: http://<STRATUM1_IP>/cvmfs/repo.organization.tld through proxy http://<PROXY_IP>:3128 (online)

Testing

This repository uses the Ansible Molecule framework for testing.

Installation / Setup

1. Install pip, ansible, and podman. On Debian, they can all be installed with apt.

   sudo apt install -y pip podman ansible

   Otherwise, follow these instructions to install podman and molecule

   • podman: https://podman.io/docs/installation
   • molecule: https://ansible.readthedocs.io/projects/molecule/installation/

2. Create a python environment that you can use from root.

   python3 -m venv cvmfs
   sudo su
   . cvmfs/bin/activate
   pip install ansible molecule molecule-podman

3. While still acting as root, and in this directory, run

   ansible-galaxy collection install . --force

Test execution

1. Move into the extensions directory

   cd extensions/

2. Then, still as root, run

   molecule test

   to keep the test environment around after the tests are complete, you can instead run

   molecule destroy && molecule test --destroy=never

Footnotes

1. https://cvmfs-contrib.github.io/cvmfs-tutorial-2021/02_stratum0_client/#216-adding-files-to-the-repository ↩

2. https://cvmfs-contrib.github.io/cvmfs-tutorial-2021/03_stratum1_proxies/#316-manually-synchronize-the-stratum-1 ↩

3. https://cvmfs-contrib.github.io/cvmfs-tutorial-2021/02_stratum0_client/#223-mounting-the-repositories ↩

4. https://cvmfs-contrib.github.io/cvmfs-tutorial-2021/03_stratum1_proxies/#333-test-the-new-configuration ↩