Move NVIDIA MIG configuration to pure systemd with templating, and colon seperating GPU indexs instead of spaces

Signed-off-by: root <root@warewulf>

overlays/mig/rootfs/etc/systemd/system/nvidia-mig.service.ww

@@ -1,13 +0,0 @@
-[Unit]
-DefaultDependencies=no
-Description=Configure NVIDIA MIG (Multi-Instance GPU) partitions at boot time
-Before=nvidia-persistenced.service nvidia-dcgm.service dcgm_exporter.service
-
-[Service]
-Type=oneshot
-RemainAfterExit=yes
-ExecStart=/usr/local/sbin/_config_mig "{{ .Tags.gpuMigType | default "2,2" }}"
-ExecStop=sh -c 'nvidia-smi mig -dci ; nvidia-smi mig -dgi ; nvidia-smi -mig 0'
-
-[Install]
-WantedBy=multi-user.target

overlays/mig/rootfs/etc/systemd/system/ww-nvidia-mig.service.ww

@@ -0,0 +1,32 @@
+[Unit]
+DefaultDependencies=no
+Description=Configure NVIDIA MIG (Multi-Instance GPU) partitions via Warewulf
+Before=nvidia-persistenced.service nvidia-dcgm.service dcgm_exporter.service nvsm.service nvsm-core.service
+ConditionPathExists=/usr/bin/nvidia-smi
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStartPre=-/usr/bin/nvidia-smi -pm 1
+ExecStartPre=/usr/bin/nvidia-smi -mig 1
+{{- $rawMigProfiles := default "2,2" .Tags.gpuMigProfiles -}}
+{{- $migProfiles := splitList ":" $rawMigProfiles -}}
+{{- if gt (len $migProfiles) 1 -}}
+{{- range $gpuIndex, $migProfile := $migProfiles -}}
+  {{- if ne $migProfile "" }}
+ExecStart=/usr/bin/nvidia-smi mig -cgi {{$migProfile}} -i {{$gpuIndex}} -C
+  {{- end -}}
+{{- end -}}
+{{- else }}
+ExecStart=/usr/bin/nvidia-smi mig -cgi {{$rawMigProfiles}} -C
+{{- end }}
+ExecStartPost=-/usr/bin/nvidia-smi -L
+ExecStartPost=-/usr/bin/sh /usr/local/sbin/mig2gres
+ExecStop=-/usr/bin/nvidia-smi mig -dci
+ExecStop=-/usr/bin/nvidia-smi mig -dgi
+ExecStop=/usr/bin/nvidia-smi -mig 0
+TimeoutStartSec=300
+TimeoutStopSec=300
+
+[Install]
+WantedBy=multi-user.target

overlays/mig/rootfs/usr/local/sbin/_config_mig

@@ -1,37 +0,0 @@
-#!/usr/bin/bash
-set -euo pipefail
-
-# This script configures NVIDIA MIG (Multi-Instance GPU) partitions based on the provided
-# gpuMigType string argument. It supports both a single configuration for all GPUs or
-# individual configurations per GPU.
-# Example inputs:
-#   "14,14,14,15"               # single config for all GPUs
-#   "14,14,14,15 7,7,7,8"  # per-GPU configs for GPU0 and GPU1
-
-# See https://docs.nvidia.com/datacenter/tesla/mig-user-guide/supported-mig-profiles.html for details on supported MIG profiles
-
-# Get the gpuMigType string from the first argument
-MIG_STRING="${1}"
-if [[ -z "$MIG_STRING" ]]; then
-  echo "Usage: $0 <gpuMigType string>" >&2
-  exit 1
-fi
-
-# Check if nvidia-smi command exists
-if ! command -v nvidia-smi &> /dev/null; then
-  echo "Error: nvidia-smi command not found" >&2
-  exit 1
-fi
-
-# enable MIG mode
-nvidia-smi -mig 1
-
-# per-GPU space-separated list (one token per GPU), otherwise single-string common case
-if [[ "$MIG_STRING" == *" "* ]]; then
-  read -a PER_GPU_MIG_CONFIGS <<< "$MIG_STRING"
-  for gpu_index in "${!PER_GPU_MIG_CONFIGS[@]}"; do
-    nvidia-smi mig -cgi "${PER_GPU_MIG_CONFIGS[$gpu_index]}" -i "$gpu_index" -C
-  done
-else
-  nvidia-smi mig -cgi "$MIG_STRING" -C
-fi

overlays/mig/rootfs/usr/local/sbin/mig2gres

@@ -14,6 +14,21 @@ if ! command -v nvidia-smi &> /dev/null; then
   exit 1
 fi
 
+if ! command -v grep &> /dev/null; then
+  echo "Error: grep command not found" >&2
+  exit 1
+fi
+
+if ! command -v awk &> /dev/null; then
+  echo "Error: awk command not found" >&2
+  exit 1
+fi
+
+if ! command -v hostname &> /dev/null; then
+  echo "Error: hostname command not found" >&2
+  exit 1
+fi
+
 hostname=$(hostname -s)
 
 nvidia-smi mig -lgi | grep -E '^\|' | grep -v '===' | grep -v 'GPU.*Name' | while read line; do
@@ -25,6 +40,7 @@ nvidia-smi mig -lgi | grep -E '^\|' | grep -v '===' | grep -v 'GPU.*Name' | whil
 
   pattern="gpu${gpu}/gi${gi}/access"
   minor=$(grep "^${pattern} " /proc/driver/nvidia-caps/mig-minors | awk '{print $2}')
+  device_file="/dev/nvidia-caps/nvidia-cap${minor}"
 
-  echo "NodeName=${hostname} Name=gpu Type=${name} File=/dev/nvidia-caps/nvidia-cap${minor}"
+  echo "NodeName=${hostname} Name=gpu Type=${name} File=${device_file}"
 done