Packaging with Spack

Repository for the Spack exercise. The code is a slightly modified version of the code used in the CMake exercise.

The directory docker/ contains the recipe of the Docker image that has been prepared for the exercise. Build a Docker image from the recipe and start a container from this image.

My elaborations

I implemented all mandatory tasks and most optional tasks. In the following, the structure of my elaboration is explained, and information for reproducing the results is provided.

Building and launching the docker container

All of the following commands are to be executed from within the docker folder. I built the docker container with

sudo docker build -t spack-exercise .

and ran it with

sudo docker run -it --mount type=bind,src=..,dst=/mnt/host/ spack-exercise

What should be done from there on depends on whether only the mandatory tasks or also the optional tasks are considered.

Mandatory tasks

For reproducing the results of the mandatory tasks, proceed as follows:

spack create https://github.com/Simulation-Software-Engineering/spack-exercise/archive/refs/tags/v0.3.0.tar.gz
# Press 'c' and enter
# Escape Vim without any changes (type ':wq' and enter)
cd /home/spackbuilder/.spack/package_repos/fncqgg4/repos/spack_repo/builtin/packages/spack_exercise/
cp /mnt/host/mandatory-exercise/package.py .

# v0.1.0
spack install spack-exercise@0.1.0
spack load spack-exercise@0.1.0
spackexample
spack unload spack-exercise@0.1.0

# v0.2.0
spack install spack-exercise@0.2.0
spack load spack-exercise@0.2.0
spackexample
spack unload spack-exercise@0.2.0

# v0.3.0
spack install spack-exercise@0.3.0
spack load spack-exercise@0.3.0
spackexample /mnt/host/yamlParser/config.yml

This part is fully compliant with the exercise template and assumes the unaltered C++ code and CMakeLists.txt provided there.

Optional tasks

I completed the following optional tasks:

1. Add the main branch of the GitHub repository as version to the Spack recipe.
2. Make the current dependencies (Boost, yaml-cpp) optional by defining suitable options in the CMakeLists.txt which are also picked up in the C++ code. Then add corresponding variants in the Spack recipe which allow to turn on/off these features.

The corresponding package.py is located at the folder optional-exercise. The first optional task is straightforward. I implemented the second task such that the user can modify two separate variants, namely boost and yamlcpp. By default, both are true. Notice that the releases are not available in forks of the exercise repository, but the package.py assumes they are, since that would be the case in a realistic workflow.

Notice that the ability to specify whether the functionality relying on boost and yaml-cpp should be built or not requires changes to the source code and the CMakeLists.txt. The required changes were applied in the C++ code and CMakeLists.txt contained within this branch. To reproduce the results without troubles, please mind executing

spack create https://github.com/MarcelGraf0710/spack-exercise

instead of the link to the tar.gz belonging to the exercise template.

To reproduce the results of the optional tasks with boost and yamlcpp disabled, proceed as follows:

# Create package.py stub from my fork

spack create https://github.com/MarcelGraf0710/spack-exercise
# Escape Vim without any changes (type ':wq' and enter)
cd /home/spackbuilder/.spack/package_repos/fncqgg4/repos/spack_repo/builtin/packages/spack_exercise/
cp /mnt/host/optional-exercise/package.py .

# Install spack-exercise/main with boost and yaml-cpp disabled
spack install spack-exercise -boost -yamlcpp
spack load spack-exercise
spackexample /mnt/host/yamlParser/config.yml

The boost and yamlcpp variants do not depend on each other, so you may test arbitrary combinations of those.