README-Docker

This README will address using a Docker container to build and run the Basis
version of Uedge. The Basis Uedge version is deprecated and is provided for 
legacy applications only and provided/supported only for local Program 
developers use. New users should use the Python Uedge module. For the remainder
 of this readme the name Uedge will only refer to the Basis version.

Basis is a high-level programming language. It's similar to Python in that it 
allows user developed applications to be run interactively. It was developed at
LLNL, and as was already indicated, is deprecated and no long supported. 

Docker is a virtualization platform for running applications inside containers.
It doesn't require the user create a full virtual machine so is lighter weight.
To get started you need to install Docker from https://www.docker.com. You may 
use the free install option to run the Docker container image we've created for
Uedge. Once you have Docker installed you should verify that it works by running
the hello-world container with "docker run -it --rm hello-world". 

The Uedge container contains the full build environment required to build and 
run some simple tests. The Uedge container is fusionbillm/basisuedge. There are
many ways it may be run and you should refer to the Docker documentation for any
thing not covered here. What follows is the expected uses of this container with
runstrings and actions described:

docker run -it --rm fusionbillm/basisuedge
      This will pull the latest master branch of Uedge, build, and run the
      some simple tests. Returns to host with 0=success or 1=failure.
docker run -it --rm fusionbillm/basisuedge checkout develop
      This passes the argument after the container name to git after the pull.
      In this case a "git pull" followed by a "git checkout develop". Then
      the usual build and tests are run. Returns to host with 0=success or
      1=failure.
docker run -it --rm --entrypoint /bin/bash fusionbillm/basisuedge
      This just runs the container and you should receive a bash shell prompt.
      The ~/UEDGE directory is a git clone with the master branch checked out.
      A "git pull" should be done there to update the clone. There is a shell
      script there, ~/basisuedge.sh, you can run or just examine. It is what
      executes the build and test actions. Running it will leave you at the
      bash shell prompt inside the container.


Graphics
========

Uedge is compiled to use the X11 protocol to produce graphics from the NCAR 
graphics library. Since Docker is not a full VM, or running a Desktop, the 
graphics are output to the host display. The protocol is X11 regardless of the 
host, the trick is to tunnel the protocol and authenticate with the display X11
server. The command syntax is depends on the host type. 

Mac:
docker run -it --rm -e DISPLAY=host.docker.internal:0 --entrypoint /bin/bash fusionbillm/basisuedge

Linux:
docker run -it --rm -e DISPLAY=$DISPLAY --volume="$HOME/.Xauthority:/home/user/.Xauthority:rw" -v /tmp/.X11-unix:/tmp/.X11-unix --network=host --entrypoint /bin/bash fusionbillm/basisuedge

Windows:
This needs to be determined. It's assumed that an X11 environment would need to
be run in the Windows host.