Add ability to reload config file for warewulfd on SIGHUP

internal/pkg/warewulfd/warewulfd.go

@@ -3,6 +3,9 @@ package warewulfd
 import (
 	"github.com/hpcng/warewulf/internal/pkg/wwlog"
 	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
 )
 
 // TODO: https://github.com/danderson/netboot/blob/master/pixiecore/dhcp.go
@@ -10,6 +13,23 @@ import (
 
 func RunServer() error {
 
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, syscall.SIGHUP)
+
+	go func() {
+		for _ = range c {
+			err := LoadNodeDB()
+			if err != nil {
+				wwlog.Printf(wwlog.WARN, "Could not load database: %s\n", err)
+			}
+		}
+	}()
+
+	err := LoadNodeDB()
+	if err != nil {
+		wwlog.Printf(wwlog.WARN, "Could not load database: %s\n", err)
+	}
+
 	wwlog.Printf(wwlog.DEBUG, "Registering handlers for the web service\n")
 
 	http.HandleFunc("/ipxe/", IpxeSend)
@@ -21,7 +41,11 @@ func RunServer() error {
 
 	wwlog.Printf(wwlog.VERBOSE, "Starting HTTPD REST service\n")
 
-	http.ListenAndServe(":9873", nil)
+	err = http.ListenAndServe(":9873", nil)
+	if err != nil {
+		wwlog.Printf(wwlog.ERROR, "Could not start listening service: %s\n", err)
+		os.Exit(1)
+	}
 
 	return nil
 }