Support dracut booting with GRUB

Signed-off-by: Jonathon Anderson <janderson@ciq.com>

etc/grub/grub.cfg.ww

@@ -6,13 +6,16 @@ echo "Warewulf Controller: {{.Ipaddr}}"
 echo
 sleep 1
 smbios --type1 --get-string 8 --set assetkey
+
 uri="(http,{{.Ipaddr}}:{{.Port}})/provision/${net_default_mac}?assetkey=${assetkey}"
 kernel="${uri}&stage=kernel"
 container="${uri}&stage=container&compress=gz"
 system="${uri}&stage=system&compress=gz"
 runtime="${uri}&stage=runtime&compress=gz"
-set default=ww4
+
+set default={{ or .Tags.GrubMenuEntry "ww4" }}
 set timeout=5
+
 menuentry "Network boot node: {{.Id}}" --id ww4 {
     {{if .KernelOverride }}
     echo "Kernel:                {{.KernelOverride}}"
@@ -34,17 +37,54 @@ menuentry "Network boot node: {{.Id}}" --id ww4 {
         reboot
     fi
 }
+
+menuentry "Network boot node with dracut: {{.Id}}" --id dracut {
+    initramfs="${uri}&stage=initramfs"
+
+    uri="http://{{.Ipaddr}}:{{.Port}}/provision/${net_default_mac}?assetkey=${assetkey}"
+    container="${uri}&stage=container&compress=gz"
+    system="${uri}&stage=system&compress=gz"
+    runtime="${uri}&stage=runtime&compress=gz"
+
+    {{if .KernelOverride }}
+    echo "Kernel:                {{.KernelOverride}}"
+    {{else}}
+    echo "Kernel:                {{.ContainerName}} (container default)"
+    {{end}}
+    echo "KernelArgs:            {{.KernelArgs}}"
+
+    net_args="rd.neednet=1 {{range $devname, $netdev := .NetDevs}}{{if and $netdev.Hwaddr $netdev.Device}} ifname={{$netdev.Device}}:{{$netdev.Hwaddr}} {{end}}{{end}}"
+    wwinit_args="root=wwinit wwinit.container=${container} wwinit.system=${system} wwinit.runtime=${runtime} init=/init"
+    linux $kernel wwid=${net_default_mac} {{.KernelArgs}} $net_args $wwinit_args
+
+    if [ x$? = x0 ] ; then
+        echo "Loading Container:     {{.ContainerName}}"
+        initrd $initramfs
+        boot
+    else
+        echo "MESSAGE: This node seems to be unconfigured. Please have your system administrator add a"
+        echo "         configuration for this node with HW address: ${net_default_mac}"
+        echo ""
+        echo "Rebooting in 1 minute..."
+        sleep 60
+        reboot
+    fi
+}
+
 menuentry "Chainload specific configfile" {
     conf="(http,{{.Ipaddr}}:{{.Port}})/efiboot/grub.cfg"
     configfile $conf
 }
+
 menuentry "UEFI Firmware Settings" --id "uefi-firmware" {
     fwsetup
 }
+
 menuentry "System restart" {
     echo "System rebooting..."
     reboot
 }
+
 menuentry "System shutdown" {
     echo "System shutting down..."
     halt