Foam-Extend CPL socket

This repository assembles a Docker image which has what's needed to run coupled Foam-Extend 5.0 (nextRelease branch) - LAMMPS (Back from this commit in the stable branch) through the CPL-library.

Everything is compiled on Ubuntu 20.04 LTS with Gcc-9 and MPICH2. The image is basically used to develop the Foam-Extend socket for CPL, so you'll have to compile it separately.

Important notes about the Docker image

• The image is MPI-ready and you can use it on a Docker Swarm (or docker-machine) to spawn a cluster of containers.
• The default user is named openfoam with UID 1001 (Take a look at the DockerFiles/01-fe4-mpich-cpl.Dockerfile for more info)
• /cpl-library is where the source code of the CPL library lives
• ~/foam/foam-extend-5.0/ holds the patched Foam-Extend installation
• ~/lammps holds the patched LAMMPS installation

How to use the Docker image

WHATEVER you do on the container, do NOT install openmpi libs! For example, installing ParaView from apt repos will installing those.

1. Install Docker if you don't have it yet: bash <(curl -s https://get.docker.com/)
2. Create a temporary container to play around with the library.
   • Create a temporary folder (you need to create this folder with the user running docker), for example: rm -rf /tmp/data && mkdir /tmp/data
   • Basically: docker run --rm -v /tmp/data:/home/openfoam/data -u $(id -u) -it foamscience/fe4-mpich-cpl-lammps:latest bash
3. You can then clone this repo there and compile with make after sourcing the SOURCEME.sh file

examples/LAMMPS-OPENFOAM from this repo is an attempt to adapt /cpl-library/examples/LAMMPS-OPENFOAM (the original example) to work with the example solver (icoFoam).

The docker image is designed to develop the FoamExtend-LAMMPS socket, typically you'd want to create a permanent cpl container, which has access to your hosts's display:

docker run -u $(id -u) --name cpl --net host -e "DISPLAY" \
    -v /tmp/.X11-unix:/tmp/.X11-unix -v /tmp/data:/home/openfoam/data \
    -it foamscience/fe4-mpich-cpl-lammps:latest bash

On your host, run xauth list, you'll something like this:

MACHINE_NAME/unix:  ...  xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Get into the container, and run this command to give permission to the container so we can attach to the display from there:

# :1 here is the display; can be different for you, run this on the host: echo $DISPLAY 
# Replace MACHINE_NAME and the hash with values from the host
touch /home/openfoam/.Xauthority
xauth add :1  MACHINE_NAME/unix  xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Now if you install ParaView and run it, you should see it pop up on your display.

All changes to any other components (CPL library itself, FE4 source code or LAMMPS's code) should be applied with Git patches; It eases Docker image builds

Installation of the Foam-Extend socket

Please skim through the Docker files for installation instructions on Ubuntu 20.04 LTS (you can ignore the SSH-related commands in there).

I don't want to run things in Docker containers

Unfortunately, we need to override some code in the Pstreams part of the foam library. If you do this on your regular installation, you'll probably break it.

You can always dedicate a Foam-Extend installation to CPL-related tasks. You'll just have to apply the patches present in DockerFiles directory.

License

CPL_APP_OpenFOAM is released under the GNU GPL v3 license. Details are found in the file LICENSE that is included with the release.