Ansible Role: Lmod

An Ansible role that installs Lmod from source.

This role was written with convenient installation on HPC clusters in mind. This means that it is possible to install the actual Lmod software into a global, networked file system share on only a single host, while all other hosts install just the Lmod dependencies and the shell configuration files. Nevertheless, it is of course possible to install Lmod with this role on a single server.

Also, it is possible with this role to incrementally transition 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 update

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: The variable lmod_install should only be set to yes for the host that actually installs Lmod to the global, networked file system, all other hosts will only install the dependencies. This should be set in host_vars, see examples.

You can also specify the module file paths which will be taken over the default lmod_module_root_path:

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

This may be useful if you have legacy modules.

Site Package

You can modify the SitePackage.lua:

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

System Spider Cache

Location of the 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'

Whether to install the update system spider cache cron job:

lmod_spider_cache_cron: no
lmod_spider_cache_cron_minute: '0'

Change the paths to include when generating the system spider cache:

lmod_spider_cache_cron_modulepath:
  - '$MODULEPATH'

Note: It may be useful to append paths here other than the default MODULEPATH, especially for communities within your system that provide their own module directories. Suppose your default is /software/modules, which everyone gets, but you also have /software/community/group-{a,b,c}/modules, which can be included on demand. By adding these paths to the system spider cache, it will include those modules transparently, i.e. you would only be able to find them with module spider, if you had included that module directory in your MODULEPATH.

For HPC clusters: This is also needed only on a single host, following the same rules as lmod_install, see examples.

Shell Configuration

Names of the shell configuration files which will be written to /etc/profile.d:

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

Changing these is only required if they need to be source'd in a specific order, e.g. if another script requires the module or ml functions, they need to be source'd after the Lmod files.

Incremental Roll-Out

This module provides a way for incremental roll-out aka canary release. This may be important if you are migrating from another environment module system to Lmod.

Note: For more information about canary releases in general, see this blog post. The Lmod documentation this specific incremental roll-out is based on can be found here.

lmod_canary: no

This variable has three possible values:

1. no: do not use incremental roll-out, every user will init Lmod
2. 'opt-in': installs custom scripts that inits Lmod only if opt-in file exists
3. 'opt-in-skel': same as opt-in plus also installs automatically opt-in new users via skeleton in /etc/skel
4. 'opt-out': installs custom scripts that don't init Lmod if opt-out file exists

Note: You can switch from opt-in to opt-in-skel, from both opt-in variants to opt-out and from opt-out to no, the tasks provided by this role will handle these transitions automatically.

These are the file names for opt-in and opt-out that are looked for in the users home directory:

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

Note: If you are using the incremental roll-out, you simply need to let your users know that they need to touch ~/.lmod-yes for opt-in, touch ~/.lmod-no for opt-out and to remove these files if they want to fallback to the respective default behavior.

Administrative Messages

Optionally, you can define administrative messages for modules to be shown when they are loaded:

lmod_admin_messages:

  - pattern: gcc/2%.95
    message: >-
      This module is deprecated and will be removed from the system on Jan 1
      1999. 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 conditionally depends on geerlingguy.repo-epel for RedHat-based distributions to install runtime and build dependencies. Not all of these dependencies are included in default repositories.

Example Playbook

Add to requirements.yml:

---

# optional
# - src: geerlingguy.repo-epel

- src: idiv-biodiversity.lmod

...

Download:

$ ansible-galaxy install -r requirements.yml

For HPC clusters: As explained above, some variables need to be set only on the master/head host (whatever you call it). You should set these in the respective host_vars file, e.g. host_vars/head.yml:

---

lmod_install: yes
lmod_spider_cache_cron: yes

...

Top-Level Playbook

Write 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

This role was created in 2017 by Christian Krause aka wookietreiber at GitHub, HPC cluster systems administrator at the German Centre for Integrative Biodiversity Research (iDiv). Ubuntu Bionic support was added by Tom Schoonjans, Research Software Engineer for HPC and Cloud at the Rosalind Franklin Institute.