Ansible Role: Lmod

This Ansible role helps in installing Lmod from its source code.

It is designed for easy installation on HPC clusters. You can install the Lmod software on one server in a shared file system, while other servers only need to install the required dependencies and shell configuration files. However, you can also use this role to install Lmod on a single server.

This role also allows you to gradually switch from another module system to Lmod.

Table of Contents

• Requirements
• Role Variables
  • Base Variables
  • System Spider Cache
  • Shell Configuration
  • Incremental Roll-Out
  • Administrative Messages
• Dependencies
• Example Playbook
  • Top-Level Playbook
  • Role Dependency
• License
• Author Information

Requirements

• Ansible 2.4
• cron for regular system spider cache updates

Role Variables

Base Variables

lmod_version: '7.7.14'
lmod_install: no
lmod_prefix: '/opt/apps'
lmod_module_root_path: '{{ lmod_prefix }}/modulefiles'

For HPC clusters: Set lmod_install to yes only for the server that installs Lmod globally. Other servers should install only the dependencies. Set this in host_vars, see examples.

You can customize module file paths like this:

lmod_module_paths:
  - '/software/modulefiles/compiler'
  - '/software/modulefiles/libraries'
  - '/software/modulefiles/tools'

Site Package

Modify the SitePackage.lua:

lmod_site_package: path/to/my/templates/SitePackage.lua

System Spider Cache

Location for system spider cache files:

lmod_spider_cache_dir: '{{ lmod_module_root_path }}/.spider-cache'
lmod_spider_cache_stamp_file: '{{ lmod_module_root_path }}/.spider-cache.stamp'

Decide if you want to install the cron job to update the system spider cache:

lmod_spider_cache_cron: no
lmod_spider_cache_cron_minute: '0'

You can include additional paths when generating the system spider cache:

lmod_spider_cache_cron_modulepath:
  - '$MODULEPATH'

Note: It might be helpful to add other paths for specific communities that have their own module directories.

For HPC clusters: Only needed on one server, similar to lmod_install, see examples.

Shell Configuration

Set the names for shell configuration files to be saved in /etc/profile.d:

lmod_init_bash_file: 'z00-lmod.sh'
lmod_init_csh_file: 'z00-lmod.csh'

Change these only if necessary for specific file sourcing order.

Incremental Roll-Out

This role supports incremental roll-out or canary release for transitioning from another module system to Lmod.

lmod_canary: no

This variable can take three values:

1. no: Everyone uses Lmod.
2. 'opt-in': Lmod only initializes if an opt-in file exists.
3. 'opt-in-skel': Same as opt-in, but automatically applies to new users.
4. 'opt-out': Lmod doesn't initialize if an opt-out file exists.

Note: You can switch between these options, and the role will manage the transitions.

Expected file names for opt-in and opt-out:

lmod_canary_opt_in_file: '.lmod-yes'
lmod_canary_opt_out_file: '.lmod-no'

Note: Inform users to create these files to switch between options.

Administrative Messages

Optionally, you can show messages when certain modules are loaded:

lmod_admin_messages:
  - pattern: gcc/2%.95
    message: >-
      This module is deprecated and will be removed. Please switch to a newer compiler.
  - pattern: /opt/apps/modulefiles/Compiler/gcc/4.7.2/boost/1.55.0
    message: We are having issues.
  - pattern: boost/1%.[5-7].*
    message: We are having more issues.

Dependencies

This role may require geerlingguy.repo-epel for RedHat distributions to install dependencies.

Example Playbook

Add to requirements.yml:

---
# optional
# - src: geerlingguy.repo-epel
- src: idiv-biodiversity.lmod

Download with:

$ ansible-galaxy install -r requirements.yml

For HPC clusters: Some variables should be set for the main server in host_vars, e.g. host_vars/head.yml:

---
lmod_install: yes
lmod_spider_cache_cron: yes

Top-Level Playbook

Create a top-level playbook:

---
- name: head server
  hosts: head
  roles:
    - role: idiv-biodiversity.lmod
      tags:
        - lmod
        - modules
  vars:
    lmod_prefix: '/software'
    lmod_install: yes
    lmod_canary: 'opt-in'

Role Dependency

Define the role dependency in meta/main.yml:

---
dependencies:
  - role: idiv-biodiversity.lmod
    vars:
      lmod_prefix: '/software'
      lmod_canary: 'opt-in'
    tags:
      - lmod
      - modules

License

MIT

Author Information

Created in 2017 by Christian Krause, HPC cluster systems administrator at the German Centre for Integrative Biodiversity Research (iDiv). Additional support for Ubuntu was provided by [Tom Schoonjans][tschoonj].