Add option for wwclient port number

With this change, you can specify a port number for wwclient.
If

  wwclient:
    port: NUMBER

is specified in warewulf.conf, wwclient will bind to the specified local
port NUMBER. If no port is specified, wwclient will use any available
port, or port 987 if secure is true.

Port 987 is in the default port range used by the Linux NFS client
(665-1023, see linux/include/linux/sunrpc/xprtsock.h). Changing
the port can avoid failures when port 987 is already in use.

Signed-off-by: Tobias Poschwatta <poschwatta@zib.de>

internal/app/wwclient/root.go

@@ -98,7 +98,10 @@ func CobraRunE(cmd *cobra.Command, args []string) (err error) {
 	}
 
 	localTCPAddr := net.TCPAddr{}
-	if conf.Warewulf.Secure {
+	if conf.WWClient != nil && conf.WWClient.Port > 0 {
+		localTCPAddr.Port = int(conf.WWClient.Port)
+		wwlog.Info("Running from configured port %d", conf.WWClient.Port)
+	} else if conf.Warewulf.Secure {
 		// Setup local port to something privileged (<1024)
 		localTCPAddr.Port = 987
 		wwlog.Info("Running from trusted port")

internal/pkg/config/root.go

@@ -41,6 +41,7 @@ type RootConf struct {
 	SSH             *SSHConf      `yaml:"ssh,omitempty"`
 	MountsContainer []*MountEntry `yaml:"container mounts" default:"[{\"source\": \"/etc/resolv.conf\", \"dest\": \"/etc/resolv.conf\"}]"`
 	Paths           *BuildConfig  `yaml:"paths"`
+	WWClient        *WWClientConf `yaml:"wwclient"`
 
 	warewulfconf string
 }

internal/pkg/config/wwclient.go

@@ -0,0 +1,5 @@
+package config
+
+type WWClientConf struct {
+	Port uint16 `yaml:"port" default:"0"`
+}