Add support for GPU instances on AWS

[willprice]

Currently launching instances with GPUs on AWS does not provision the VMs with the necessary drivers capable of interacting with the GPUs. It would be good to have some documentation for people who wish to use CitC in this manner. I plan on working on this today and will hopefully submit some PRs with instructions on this.

[colinsauze]

For my first go at getting a GPU image build I added the following to compute_image_extra.sh, just got this built but nvidia-smi is complaining about drivers.

sudo dnf config-manager --add-repo https://developer.download.nvidia.com/compute/cuda/repos/rhel8/x86_64/cuda-rhel8.repo
sudo dnf clean all
sudo dnf -y module install nvidia-driver:latest-dkms
sudo dnf -y install cuda

[willprice]

As noted by @colinsauze, It is also necessary to increase the size of the image, this can be achieved by adding the following

    launch_block_device_mappings { 
           device_name = "/dev/sda1"
           volume_size =  40
    }

to the end of the source "amazon-ebs" "aws" section in /etc/citc/packer/all.pkr.hcl

[willprice]

It is also necessary to install kernel-devel before install the nvidia drivers to ensure that the dkms module can be built, without that it will fail.

[willprice]

Docs are being updated at https://github.com/willprice/docs/blob/aws-nvidia-instructions/source/running.rst#aws-gpu-nodes

[willprice]

Once clusterinthecloud/docs#17 is merged, this can be closed.