module files : explicit load and mnemonic suffixes

[alalazo]

Modifications

• adds a new keyword load to the spec subsection in modules.yaml
• adds a new keyword suffixes to the spec subsection in modules.yaml
• generates module files with explicit module load
• unit tests for modules.py

Example : explicit load

A configuration file like :

modules:
  tcl:
    %gcc@4.8:
      load:
        - foo/bar
        - baz

will add the following lines to anything compiled with gcc@4.8:

if ![ is-loaded foo/bar ] {
    puts stderr "Autoloading foo/bar"
    module load foo/bar
}

if ![ is-loaded baz ] {
    puts stderr "Autoloading baz"
    module load baz
}

Dotkit will exhibit the same behavior.

Example : mnemonic suffixes

A configuration file like :

modules:
  tcl:
    hdf5:
      suffixes:
        +mpi: parallel

will append to any hdf5 module file the suffix parallel if +mpi in spec, producing a module file name like:

hdf5-1.10.0-gcc-6.1.0-parallel-vhxsri5po6nzynspknbjbo6uot6stcrv

@glennpj This should address the request for features made here, any feedback is welcome

[glennpj]

@alalazo Sorry for the delayed response. I have not had a chance to test yet but this looks good and addresses the use case I brought up. Are the suffixes meant to help with making the module names more friendly for humans?

Thanks.

[glennpj]

@alalazo One potential use case I see for suffixes would be to assign a name to a set of constraints/specs that are common across packages. For example, a package built with the combination of gcc/openmpi/openblas, with respective versions, could be assigned a suffix that would represent that set. That would allow the module names to be parsable by humans while maintaining the hash for guaranteed uniqueness and a check on the reproducibility of the build.

[glennpj]

@alalazo I tested this and it seems to work fine.

Thanks.

[alalazo]

@tgamblin If you have time to have a look, I think this is ready to be merged

[alalazo]

@glennpj Sorry for the late reply. For suffixes : your guess is 100% correct. I put that feature in because of the many requests I had internally for some mnemonic suffix to distinguish different variants of a package directly from the module file name.

[gartung]

@alalazo This is just what I was looking for. We have a package called ROOT that has a builtin C++ parser Cling (based on Clang) that calls gcc to determine where the system headers are located. With this option I can make gcc load when root is loaded.

[alalazo]

@gartung Glad I have been of help!

[robertdfrench]

@alalazo @tgamblin This would be very valuable for us, namely for distinguishing between the umpteen different petsc variations.

[alalazo]

@tgamblin @trws another one ready to be reviewed 😄

[tgamblin]

@alalazo We finally got #561 in, but it seems to conflict -- can you update and I'll review this?

[alalazo]

@tgamblin done

[alalazo]

@tgamblin The PR is ready to be reviewed

[tgamblin]

@alalazo: merged! sorry for the delay.