Revert "Move configuration code out of wwctl"

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

@@ -1,10 +1,117 @@
 package hosts
 
 import (
-	"github.com/hpcng/warewulf/internal/pkg/configure"
+	"bytes"
+	"os"
+	"path"
+	"text/template"
+
+	"github.com/hpcng/warewulf/internal/pkg/buildconfig"
+	"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"
 )
 
-func CobraRunE(cmd *cobra.Command, args []string) error {
-	return configure.Configure("hosts", setShow)
+type TemplateStruct struct {
+	PrevHostFile string
+	Ipaddr       string
+	Fqdn         string
+	AllNodes     []node.NodeInfo
+}
+
+func CobraRunE(cmd *cobra.Command, args []string) error {
+	return Configure(SetShow)
+}
+
+func Configure(show bool) error {
+	var replace TemplateStruct
+
+	if !util.IsFile(path.Join(buildconfig.SYSCONFDIR(), "warewulf/hosts.tmpl")) {
+		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(path.Join(buildconfig.SYSCONFDIR(), "warewulf/hosts.tmpl"))
+	if err != nil {
+		wwlog.Printf(wwlog.ERROR, "Could not parse hosts template: %s\n", err)
+		os.Exit(1)
+	}
+
+	replace.PrevHostFile = ""
+	w, err := os.Open("/etc/hosts")
+	if err != nil {
+		wwlog.Printf(wwlog.WARN, "%s\n", err)
+	} else {
+		// if /etc/hosts.ww does not exist, backup /etc/hosts to /etc/hosts.wwbackup
+		if !util.IsFile("/etc/hosts.wwbackup") {
+			err = util.CopyFile("/etc/hosts", "/etc/hosts.wwbackup")
+			if err != nil {
+				wwlog.Printf(wwlog.ERROR, "%s\n", err)
+			}
+		}
+
+		// read all lines before the # warewulf comment and put into PrevHostFile template variable
+		lines, _ := util.ReadFile("/etc/hosts")
+		if lines != nil {
+			var buffer bytes.Buffer
+			for _, line := range lines {
+				//wwlog.Printf(wwlog.INFO, "Reading line: %s\n", line)
+				if util.ValidString(line, "^#.*maintained by warewulf") {
+					break
+				}
+				buffer.WriteString(line)
+				buffer.WriteString("\n")
+			}
+			replace.PrevHostFile = buffer.String()
+		}
+	}
+
+	//wwlog.Printf(wwlog.INFO, "PrevHostFile is %s\n", replace.PrevHostFile)
+
+	w.Close()
+
+	nodes, _ := n.FindAllNodes()
+
+	replace.AllNodes = nodes
+	replace.Ipaddr = controller.Ipaddr
+	replace.Fqdn = controller.Fqdn
+
+	if !SetShow {
+		// only open "/etc/hosts" when intended to write, as 'os.O_TRUNC' will empty the file otherwise.
+		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()
+
+		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
 }

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

@@ -4,18 +4,18 @@ import "github.com/spf13/cobra"
 
 var (
 	baseCmd = &cobra.Command{
-		DisableFlagsInUseLine: true,
-		Use:                   "hosts [OPTIONS]",
-		Short:                 "Update the /etc/hosts file",
+                DisableFlagsInUseLine: true,
+		Use:   "hosts [OPTIONS]",
+		Short: "Update the /etc/hosts file",
 		Long: "Write out the /etc/hosts file based on the Warewulf template (hosts.tmpl) in the\n" +
 			"Warewulf configuration directory.",
 		RunE: CobraRunE,
 	}
-	setShow bool
+	SetShow bool
 )
 
 func init() {
-	baseCmd.PersistentFlags().BoolVarP(&setShow, "show", "s", false, "Show configuration (don't update)")
+	baseCmd.PersistentFlags().BoolVarP(&SetShow, "show", "s", false, "Show configuration (don't update)")
 }
 
 // GetRootCommand returns the root cobra.Command for the application.