Use containers¶
Once containers are built it is time to use them to compile some code.
SingularityCE provides many ways to interact with containers. The idea is to use the development environment compiled within the container to build and run Rat C++ projects through it.
Important
These containers are have no “memory” and everything that was done in them that has not been saved to disk via a bind mount will NOT persist.
Results should be stored in a bound/mounted path via the -B
flag (e.g. in the /io directory following below examples),
or within the current working directory which should be
automatically mounted upon entering the container.
Interactive shell¶
The most straightforward way to interact with containers is via the interactive shell.
This approach is more suited for exploration, testing and development.
singularity shell -B $(pwd):/io <container>.sif
This will:
enter the shell container (should see the
Singularity>prompt),bind the current wordking directory to a
/iodirectory accessible from the container (-B $(pwd):/io).
Commands can be executed through this shell to access programs
within the container such as cmake, ninja, CUDA,
Rat libraries, and everything else that is installed in it.
Hint
The rat-containers/env.sh file defines a simple utility script to have a some colors for the prompt as well as some basic shell aliases that are nice to have when exploring.
Source it with source env.sh from the interactive shell.
Declarative commands¶
Commands can directly be passed to containers to be run in their environment.
This approach is more suited for running programs (e.g. on HPC).
singularity exec -B $(pwd):/io <container>.sif bash -c "echo /etc/os-release"
This will:
run the
echo /etc/os-releasefrom within the container (which should print some lore about the Linux distribution),bind the current wordking directory to a
/iodirectory accessible from the container (-B $(pwd):/io).
