Merge pull request #35 from ISISComputingGroup/uv

add docs on uv

Author: Tom-Willemsen

doc/scripting/uv.md

@@ -0,0 +1,33 @@
+# `uv` and python environments
+
+`uv` is a Python package and project manager. See [`uv`'s docs](https://docs.astral.sh/uv/) for more information.
+
+We are currently considering whether we could use it to split up our python processes and use it for python version management on instrument machines. 
+
+## `uv` files
+
+- `c:\Instrument\apps\uv\` is the main installation folder for `uv` itself. 
+- `c:\Instrument\apps\uv\snakes` is the location of individually-versioned python interpreter executables. These are "bare" interpreters, that do not contain any dependencies such as `genie_python`.
+- `c:\Instrument\var\tmp\uvcache` is the location of `uv`'s pip download cache. This can safely be deleted and will be recreated as-needed.
+
+## Details of `uv` setup
+
+### IBEX install scripts
+
+`uv` is used for a few things here. 
+
+Firstly, installing the python executable itself onto an instrument machine.
+
+Secondly, setting up a temporary virtual environment, which gets deleted at the end of the script, for using the deploy scripts themselves.
+
+### Build jobs e.g. ConfigChecker
+
+`uv` is used for creating a virtual environment for jenkins-run python checks. 
+
+It can be used on Github actions CI, but isn't currently. 
+
+### Instrument processes
+
+In the future we may consider using `uv` to create and build virtual environments for each respective python process that runs on the NDX. This requires some decisions and subsequent work: 
+- `uv.lock` files - should we keep them in source, or at least on the build server, then build virtual environments on the NDXes with those specific versions?
+- python wheels need to be available for everything we use - the NDXes do not have compilers ie. Visual Studio installed.