add CIDR format to warewulf.conf parse

CHANGELOG.md

@@ -47,6 +47,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 - Block unprivileged requests for arbitrary overlays in secure mode. #1215
 - Fix installation docs to use github.com/warewulf instead of github.com/hpcng. #1219
+- Fix the issue that warewulf.conf parse does not support CIDR format. #1130
 
 ### Security
 

internal/pkg/config/root.go

@@ -101,6 +101,19 @@ func (conf *RootConf) Parse(data []byte) error {
 	if len(conf.TFTP.IpxeBinaries) == 0 {
 		conf.TFTP.IpxeBinaries = defIpxe
 	}
+
+	// check whether ip addr is CIDR type and configure related fields as required
+	if ip, network, err := net.ParseCIDR(conf.Ipaddr); err == nil {
+		conf.Ipaddr = ip.String()
+		if conf.Network == "" {
+			conf.Network = network.IP.String()
+		}
+		if conf.Netmask == "" {
+			mask := network.Mask
+			conf.Netmask = fmt.Sprintf("%d.%d.%d.%d", mask[0], mask[1], mask[2], mask[3])
+		}
+	}
+
 	return nil
 }