Added support for a DNSSEARCH netdev tag in network configuration overlays

- Closes: #1256

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

overlays/ifcfg/rootfs/etc/sysconfig/network-scripts/ifcfg.ww

@@ -39,8 +39,11 @@ IPV6_FAILURE_FATAL=no
 IPV6ADDR="{{ $netdev.Ipaddr6 }}"
 {{- end }}
 {{- range $tk, $tv := $netdev.Tags }}
-{{- if eq (substr 0 3 $tk) "DNS" }}
+{{- if regexMatch "^DNS[0-9]*$" $tk }}
 {{ $tk }}={{ $tv }}
 {{- end }}
 {{- end }}
+{{- if $netdev.Tags.DNSSEARCH }}
+DOMAIN="{{ join " " (without (regexSplit "[ ;]+" $netdev.Tags.DNSSEARCH -1) "") }}"
+{{- end }}
 {{- end }}