Update mig2gpu.sh to work with MIG on Cgroups on YARN

[tgravescs]

part of NVIDIA/spark-rapids#5261. There is a description in the issue how this fits in.

This adds an option to the mig2gpu.sh to publish the minor device number of the mig device as the gi access device number.

This will be used with other scripts to allow MIG to work when YARN is configured with gpu scheduling and CGROUPs. Not updating docs here as more is required and the use of this will be part of other scripts.

[viadea]

Did some quick test and it works fine to me:

Then let’s generate the output and compare:
nvidia-smi -q -x | ENABLE_MIG_GPUS_FOR_CGROUPS=1 ./mig2gpu.sh > /tmp/new.txt
nvidia-smi -q -x | ENABLE_MIG_GPUS_FOR_CGROUPS=1 ./mig2gpu.sh.old > /tmp/old.txt
Compare the new and old output:
# diff /tmp/new.txt /tmp/old.txt
9c9
< 		<minor_number>30</minor_number>
---
> 		<minor_number>0</minor_number>
35c35
< 		<minor_number>39</minor_number>
---
> 		<minor_number>0</minor_number>
61c61
< 		<minor_number>48</minor_number>
---
> 		<minor_number>0</minor_number>

[gerashegalov]

I was striving to use only bash-intrinsic operators. We could use regex matching of the input lines instead of cat, grep & cut. https://github.com/NVIDIA/spark-rapids-examples/blob/branch-22.04/examples/MIG-Support/yarn-unpatched/scripts/mig2gpu.sh#L30

[tgravescs]

thanks @gerashegalov I'll followup with this and see if I can use regex