EasyBuild

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This is not a complete article: This is a draft, a work in progress that is intended to be published into an article, which may or may not be ready for inclusion in the main wiki. It should not necessarily be considered factual or authoritative.

EasyBuild is a tool for building, installing, and maintaining software on high-performance computing systems. We use it to build almost everything in our software repository, CVMFS.

EasyBuild and modules

One of the key features of EasyBuild is that it automatically generates environment modules which can be used to make a software package available in your session. In addition to defining standard Linux environment variables such as PATH, CPATH and LIBRARY_PATH, EasyBuild also defines some environment variables specific to EasyBuild, two of which may be particularly interesting to users:

• EBROOT<name>: Contains the full path to the location where the software <name> is installed.
• EBVERSION<name>: Contains the full version of the software <name> loaded by this module.

For example, the module python/3.10.2 on Narval defines:

• EBROOTPYTHON: /cvmfs/soft.computecanada.ca/easybuild/software/2020/avx2/Core/python/3.10.2
• EBVERSIONPYTHON: 3.10.2

You can see the environment variables defined by the python/3.10.2 module using:

[name@server ~]$ module show python/3.10.2 | grep EB

Installation recipes and logs

EasyBuild keeps a copy of the recipe used to install each software package, as well as a detailed log inside of the installation directory. This is accessible in the directory $EBROOT<name>/easybuild. For example, for the python/3.10.2 module, the installation directory contains, amongst other things:

• $EBROOTPYTHON/easybuild/Python-3.10.2.eb
• $EBROOTPYTHON/easybuild/easybuild-Python-3.10.2-*.log

Using EasyBuild in your own account

EasyBuild can be used to install software packages in your own account. However, in most cases, it is preferable to ask our Technical support to install the software centrally for you. This is because that will ensure that the software package is available on all of our clusters. It will also avoid using your quota, and it will avoid causing undue load on the parallel filesystems.

When to use or not use EasyBuild to install software in your home

There are a few use cases in which you may want to use EasyBuild to install software in your own space:

• if you need a custom or modified build
• if you need to install a nightly build, or a version of a software which does not have a release number
• if we are not allowed to install the package centrally for licensing reasons, such as some commercial software packages (VASP and Materials Studio in particular)

On the contrary, you should not install software packages in your own space for the following reasons:

• if you need a different release version
• if you need a software package built using a different compiler, MPI or CUDA implementation

When in doubt, please ask our Technical support for advice.

What is a recipe

Writing a recipe from scratch will not be discussed here; you can find more about this in the EasyBuild documentation. Modifying a recipe for your particular situation is easier, and it is easier still to find a suitable recipe and use it unmodified.

Recipes, also known as EasyConfig files are text files containing the information EasyBuild needs to build a particular piece of software in a particular environment. They are named following a convention:

• <name>-<version>-<toolchain name>-<toolchain version>.eb

where <name> is the name of the package, <version> is its version, <toolchain name> is the name of the toolchain and <toolchain version> is its version. More on toolchains later.

Finding a recipe

EasyBuild contains a lot of recipes which may or may not compile with the toolchains we have. The surest way to get a recipe that works is to start from one of the recipes which we have installed. These can be found either in the installation folder, as mentioned above, or in the /cvmfs/soft.computecanada.ca/easybuild/ebfiles_repo/$EBVERSIONGENTOO folder.

What is in a toolchain?

Toolchains are a combination of compiler, MPI implementation, CUDA version, and mathematical libraries, which are used to compile the software package. They usually hold a rather obscure name such as gofbc which, in this case, means it is a combination of GCC, OpenMPI, FlexiBlas and CUDA. You do not however need to remember this naming, since toolchains themselves have recipes, which are also available in the /cvmfs/soft.computecanada.ca/easybuild/ebfiles_repo/$EBVERSIONGENTOO directory. For example, the gofbc toolchain, version 2020.1.403.114 contains, as per /cvmfs/soft.computecanada.ca/easybuild/ebfiles_repo/$EBVERSIONGENTOO/gofbc/gofbc-2020.1.403.114.eb:

local_gccver = '9.3.0'

# specify subtoolchains as builddependencies
# this way they will be considered as subtoolchains but
# are not loaded in the modulefile or software compiled
# with this toolchain
builddependencies = [
    ('gccflexiblascuda', '2020.1.114'),
    ('gompic', version),
]

dependencies = [
    ('GCC', local_gccver),  # part of gcccuda
    ('CUDA', '11.4', '', ('GCC', local_gccver)),  # part of gcccuda
    ('OpenMPI', '4.0.3', '', ('gcccuda', '2020.1.114')),
    ('FlexiBLAS', '3.0.4'),
]

which means that it contains GCC version 9.3.0, OpenMPI 4.0.3, CUDA 11.4, and FlexiBLAS 3.0.4. The builddependencies part means that the gofbc toolchain is a superset of the gompic and the gccflexiblascuda toolchains. When a toolchain is a superset of other toolchains, it allows software packages built with the former to have dependencies on software packages built with the latter, i.e. software packages built with gofbc can depend on software packages built with gompic, but not the other way around.

Installing a software with EasyBuild

Once you have found a recipe matching your needs, copy its recipe from the /cvmfs/soft.computecanada.ca/easybuild/ebfiles_repo/$EBVERSIONGENTOO folder, and modify it as needed. Then, run

[name@server ~]$ eb <recipe.eb>

to install it. This will install the software inside of your home directory, in $HOME/.local/easybuild. After the installation is completed, exit your session and reconnect to the cluster, and it should be available to load as a module.

Reinstalling an existing version

If you are reinstalling the exact same version as one we have installed centrally, but with modified parameters, you may need to use

[name@server ~]$ eb <recipe.eb> --force

to install a local version in your home.

Installing in a different location

You may want to install the software package in a different location than your home directory, for example in a project directory. To do so, use the following:

[name@server ~]$ eb <recipe.eb> --installpath /path/to/your/project/easybuild

Then, to get these modules available in your sessions, run

[name@server ~]$ export RSNT_LOCAL_MODULEPATHS=/path/to/your/project/easybuild/modules

If you want to have this available by default in your sessions, you can add this command to your .bashrc file in your home.

Additional resources

• WestGrid webinar slides "Building software on Compute Canada clusters using EasyBuild"
• Our staff-facing documentation is available here.
• Many tutorials on EasyBuild are available

Message Passing Interface

GNU Compiler Collection, an open source compiler collection