In some situations it might be necessary to build LAMMPS on a system without internet. The scripts in this folder allow you to preload external dependencies for both the documentation build for building with CMake into a folder and then use that folder on an offline system.

It does so by

1.) Downloading necessary pip packages 2.) Cloning git repositories 3.) Downloading tarballs

As of April 2021, all of these downloads make up around 600MB. By default, it will download everything into $HOME/.cache/lammps, but this can be changed with the LAMMPS_CACHING_DIR environment variable.

Once the caches have been initialized, they can be used for building LAMMPS documentation or compiling using CMake on an offline system.

The use_caches.sh must be sourced into the current shell to initialize the offline build environment. Note that it must use the same LAMMPS_CACHING_DIR. This script does the following:

1.) Sets up environment variables that modify the behavior of both pip and git 2.) Starts a simple local HTTP server to host files for CMake

Afterwards, it will print out instruction on how to modify the CMake command line to make sure it uses the local HTTP server.

To undo the environment changes and shutdown the HTTP server, run the deactivate_caches command.

Examples

For all of the examples below, you first need to create the cache (which requires internet).

./tools/offline/init_caches.sh

Afterwards, you can disconnect or copy the contents of the LAMMPS_CACHING_DIR folder to an offline system.

Documentation

# if LAMMPS_CACHING_DIR is different from default, make sure to set it first
# export LAMMPS_CACHING_DIR=path/to/folder
source tools/offline/use_caches.sh
cd doc/
make html

deactivate_caches

CMake Build

# if LAMMPS_CACHING_DIR is different from default, make sure to set it first
# export LAMMPS_CACHING_DIR=path/to/folder
source tools/offline/use_caches.sh

mkdir build
cd build
cmake -D LAMMPS_DOWNLOADS_URL=${HTTP_CACHE_URL} -C ${LAMMPS_HTTP_CACHE_CONFIG} -C ../cmake/presets/most.cmake ../cmake
make -j 8

deactivate_caches