Add ability to configure host file on the controller node

internal/app/wwctl/configure/hosts/main.go

@@ -1 +1,74 @@
 package hosts
+
+import (
+	"github.com/hpcng/warewulf/internal/pkg/node"
+	"github.com/hpcng/warewulf/internal/pkg/util"
+	"github.com/hpcng/warewulf/internal/pkg/warewulfconf"
+	"github.com/hpcng/warewulf/internal/pkg/wwlog"
+	"github.com/spf13/cobra"
+	"os"
+	"text/template"
+)
+
+type TemplateStruct struct {
+	Ipaddr   string
+	Fqdn     string
+	AllNodes []node.NodeInfo
+}
+
+func CobraRunE(cmd *cobra.Command, args []string) error {
+	var replace TemplateStruct
+
+	if util.IsFile("/etc/warewulf/hosts.tmpl") == false {
+		wwlog.Printf(wwlog.WARN, "Template not found, not updating host file\n")
+		return nil
+	}
+
+	controller, err := warewulfconf.New()
+	if err != nil {
+		wwlog.Printf(wwlog.ERROR, "%s\n", err)
+		os.Exit(1)
+	}
+
+	n, err := node.New()
+	if err != nil {
+		wwlog.Printf(wwlog.ERROR, "Could not open node configuration: %s\n", err)
+		os.Exit(1)
+	}
+
+	tmpl, err := template.ParseFiles("/etc/warewulf/hosts.tmpl")
+	if err != nil {
+		wwlog.Printf(wwlog.ERROR, "Could not parse hosts template: %s\n", err)
+		os.Exit(1)
+	}
+
+	w, err := os.OpenFile("/etc/hosts", os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
+	if err != nil {
+		wwlog.Printf(wwlog.ERROR, "%s\n", err)
+		os.Exit(1)
+	}
+	defer w.Close()
+
+	nodes, _ := n.FindAllNodes()
+
+	replace.AllNodes = nodes
+	replace.Ipaddr = controller.Ipaddr
+	replace.Fqdn = controller.Fqdn
+
+	if SetShow == false {
+		err = tmpl.Execute(w, replace)
+		if err != nil {
+			wwlog.Printf(wwlog.ERROR, "%s\n", err)
+			os.Exit(1)
+		}
+	} else {
+		err = tmpl.Execute(os.Stdout, replace)
+		if err != nil {
+			wwlog.Printf(wwlog.ERROR, "%s\n", err)
+			os.Exit(1)
+		}
+
+	}
+
+	return nil
+}