Merge pull request #467 from mslacken/single-Overlay

enable overlay rendering

internal/app/wwctl/overlay/chmod/root.go

@@ -1,6 +1,7 @@
 package chmod
 
 import (
+	"github.com/hpcng/warewulf/internal/pkg/overlay"
 	"github.com/spf13/cobra"
 )
 
@@ -13,6 +14,13 @@ var (
 		Example:               "wwctl overlay chmod default /etc/hostname.ww 0660",
 		RunE:                  CobraRunE,
 		Args:                  cobra.ExactArgs(3),
+		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+			if len(args) != 0 {
+				return nil, cobra.ShellCompDirectiveNoFileComp
+			}
+			list, _ := overlay.FindOverlays()
+			return list, cobra.ShellCompDirectiveNoFileComp
+		},
 	}
 )
 

internal/app/wwctl/overlay/chown/root.go

@@ -1,6 +1,9 @@
 package chown
 
-import "github.com/spf13/cobra"
+import (
+	"github.com/hpcng/warewulf/internal/pkg/overlay"
+	"github.com/spf13/cobra"
+)
 
 var (
 	baseCmd = &cobra.Command{
@@ -10,6 +13,13 @@ var (
 		Long:                  "This command changes the ownership of a FILE within the system or runtime OVERLAY_NAME\nto the user specified by UID. Optionally, it will also change group ownership to GID.",
 		RunE:                  CobraRunE,
 		Args:                  cobra.RangeArgs(3, 4),
+		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+			if len(args) != 0 {
+				return nil, cobra.ShellCompDirectiveNoFileComp
+			}
+			list, _ := overlay.FindOverlays()
+			return list, cobra.ShellCompDirectiveNoFileComp
+		},
 	}
 )
 

internal/app/wwctl/overlay/delete/root.go

@@ -1,6 +1,7 @@
 package delete
 
 import (
+	"github.com/hpcng/warewulf/internal/pkg/overlay"
 	"github.com/spf13/cobra"
 )
 
@@ -13,6 +14,13 @@ var (
 		RunE:                  CobraRunE,
 		Args:                  cobra.RangeArgs(1, 2),
 		Aliases:               []string{"rm", "del"},
+		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+			if len(args) != 0 {
+				return nil, cobra.ShellCompDirectiveNoFileComp
+			}
+			list, _ := overlay.FindOverlays()
+			return list, cobra.ShellCompDirectiveNoFileComp
+		},
 	}
 	Force   bool
 	Parents bool

internal/app/wwctl/overlay/edit/root.go

@@ -1,6 +1,7 @@
 package edit
 
 import (
+	"github.com/hpcng/warewulf/internal/pkg/overlay"
 	"github.com/spf13/cobra"
 )
 
@@ -12,6 +13,13 @@ var (
 		Long:                  "This command will open the FILE for editing or create a new file within the\nOVERLAY_NAME. Note: files created with a '.ww' suffix will always be\nparsed as Warewulf template files, and the suffix will be removed automatically.",
 		RunE:                  CobraRunE,
 		Args:                  cobra.ExactArgs(2),
+		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+			if len(args) != 0 {
+				return nil, cobra.ShellCompDirectiveNoFileComp
+			}
+			list, _ := overlay.FindOverlays()
+			return list, cobra.ShellCompDirectiveNoFileComp
+		},
 	}
 	ListFiles  bool
 	CreateDirs bool

internal/app/wwctl/overlay/imprt/root.go

@@ -1,6 +1,9 @@
 package imprt
 
-import "github.com/spf13/cobra"
+import (
+	"github.com/hpcng/warewulf/internal/pkg/overlay"
+	"github.com/spf13/cobra"
+)
 
 var (
 	baseCmd = &cobra.Command{
@@ -11,6 +14,13 @@ var (
 		RunE:                  CobraRunE,
 		Args:                  cobra.RangeArgs(2, 3),
 		Aliases:               []string{"cp"},
+		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+			if len(args) != 0 {
+				return nil, cobra.ShellCompDirectiveNoFileComp
+			}
+			list, _ := overlay.FindOverlays()
+			return list, cobra.ShellCompDirectiveNoFileComp
+		},
 	}
 	PermMode        int32
 	NoOverlayUpdate bool

internal/app/wwctl/overlay/list/root.go

@@ -1,6 +1,7 @@
 package list
 
 import (
+	"github.com/hpcng/warewulf/internal/pkg/overlay"
 	"github.com/spf13/cobra"
 )
 
@@ -14,6 +15,13 @@ var (
 		Args:                  cobra.MinimumNArgs(0),
 		Aliases:               []string{"ls"},
 		ValidArgs:             []string{"system", "runtime"},
+		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+			if len(args) != 0 {
+				return nil, cobra.ShellCompDirectiveNoFileComp
+			}
+			list, _ := overlay.FindOverlays()
+			return list, cobra.ShellCompDirectiveNoFileComp
+		},
 	}
 	ListContents bool
 	ListLong     bool

internal/app/wwctl/overlay/root.go

@@ -17,9 +17,9 @@ import (
 var (
 	baseCmd = &cobra.Command{
 		DisableFlagsInUseLine: true,
-		Use:   "overlay COMMAND [OPTIONS]",
+		Use:                   "overlay COMMAND [OPTIONS]",
-		Short: "Warewulf Overlay Management",
+		Short:                 "Warewulf Overlay Management",
-		Long:  "Management interface for Warewulf overlays",
+		Long:                  "Management interface for Warewulf overlays",
 	}
 )
 
@@ -34,6 +34,7 @@ func init() {
 	baseCmd.AddCommand(imprt.GetCommand())
 	baseCmd.AddCommand(chmod.GetCommand())
 	baseCmd.AddCommand(chown.GetCommand())
+
 }
 
 // GetRootCommand returns the root cobra.Command for the application.

internal/app/wwctl/overlay/show/main.go

@@ -1,11 +1,17 @@
 package show
 
 import (
+	"bufio"
+	"bytes"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"path"
+	"path/filepath"
+	"regexp"
+	"strings"
 
+	"github.com/hpcng/warewulf/internal/pkg/node"
 	"github.com/hpcng/warewulf/internal/pkg/overlay"
 	"github.com/hpcng/warewulf/internal/pkg/util"
 	"github.com/hpcng/warewulf/internal/pkg/wwlog"
@@ -17,7 +23,6 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 
 	overlayName := args[0]
 	fileName := args[1]
-
 	overlaySourceDir = overlay.OverlaySourceDir(overlayName)
 
 	if !util.IsDir(overlaySourceDir) {
@@ -32,13 +37,77 @@ func CobraRunE(cmd *cobra.Command, args []string) error {
 		os.Exit(1)
 	}
 
-	f, err := ioutil.ReadFile(overlayFile)
+	if NodeName == "" {
-	if err != nil {
+		f, err := ioutil.ReadFile(overlayFile)
-		wwlog.Printf(wwlog.ERROR, "Could not read file: %s\n", err)
+		if err != nil {
-		os.Exit(1)
+			wwlog.Printf(wwlog.ERROR, "Could not read file: %s\n", err)
+			os.Exit(1)
+		}
+
+		fmt.Print(string(f))
+	} else {
+		var host node.NodeInfo
+		nodeDB, err := node.New()
+		if err != nil {
+			wwlog.Printf(wwlog.ERROR, "Could not open node configuration: %s\n", err)
+			os.Exit(1)
+		}
+		nodes, err := nodeDB.FindAllNodes()
+		if err != nil {
+			wwlog.Printf(wwlog.ERROR, "Could not get node list: %s\n", err)
+			os.Exit(1)
+		}
+		node := node.FilterByName(nodes, []string{NodeName})
+		if len(node) != 1 {
+			wwlog.Printf(wwlog.ERROR, "%v does not identify a single node\n", NodeName)
+			os.Exit(1)
+		}
+		host = node[0]
+
+		if !util.IsFile(args[0]) {
+			wwlog.Printf(wwlog.ERROR, "%s is not a file\n", args[0])
+		}
+		tstruct := overlay.InitStruct(host)
+		tstruct.BuildSource = args[0]
+		buffer, backupFile, writeFile, err := overlay.RenderTemplateFile(overlayFile, tstruct)
+		if err != nil {
+			return err
+		}
+		if filepath.Ext(args[0]) != ".ww" {
+			wwlog.Printf(wwlog.WARN, "%s has not the '.ww' so wont be rendered if in overlay\n", args[0])
+		}
+		var outBuffer bytes.Buffer
+		// search for magic file name comment
+		bufferScanner := bufio.NewScanner(bytes.NewReader(buffer.Bytes()))
+		bufferScanner.Split(overlay.ScanLines)
+		reg := regexp.MustCompile(`.*{{\s*/\*\s*file\s*["'](.*)["']\s*\*/\s*}}.*`)
+		foundFileComment := false
+		destFileName := strings.TrimSuffix(args[0], ".ww")
+		for bufferScanner.Scan() {
+			line := bufferScanner.Text()
+			filenameFromTemplate := reg.FindAllStringSubmatch(line, -1)
+			if len(filenameFromTemplate) != 0 {
+				wwlog.Printf(wwlog.DEBUG, "Found multifile comment, new filename %s\n", filenameFromTemplate[0][1])
+				if foundFileComment {
+					if !Quiet {
+						wwlog.Printf(wwlog.INFO, "backupFile: %v\nwriteFile: %v\n", backupFile, writeFile)
+						wwlog.Printf(wwlog.INFO, "Filename: %s\n\n", destFileName)
+					}
+					wwlog.Printf(wwlog.INFO, "%s", outBuffer.String())
+					outBuffer.Reset()
+				}
+				destFileName = filenameFromTemplate[0][1]
+				foundFileComment = true
+			} else {
+				_, _ = outBuffer.WriteString(line)
+			}
+		}
+		if !Quiet {
+			wwlog.Printf(wwlog.INFO, "backupFile: %v\nwriteFile: %v\n", backupFile, writeFile)
+			wwlog.Printf(wwlog.INFO, "Filename: %s\n\n", destFileName)
+		}
+		wwlog.Printf(wwlog.INFO, "%s", outBuffer.String())
+
 	}
-
-	fmt.Print(string(f))
-
 	return nil
 }

internal/app/wwctl/overlay/show/root.go

@@ -1,6 +1,10 @@
 package show
 
 import (
+	"log"
+
+	"github.com/hpcng/warewulf/internal/pkg/node"
+	"github.com/hpcng/warewulf/internal/pkg/overlay"
 	"github.com/spf13/cobra"
 )
 
@@ -13,10 +17,32 @@ var (
 		RunE:                  CobraRunE,
 		Aliases:               []string{"cat"},
 		Args:                  cobra.ExactArgs(2),
+		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+			if len(args) != 0 {
+				return nil, cobra.ShellCompDirectiveNoFileComp
+			}
+			list, _ := overlay.FindOverlays()
+			return list, cobra.ShellCompDirectiveNoFileComp
+		},
 	}
+	NodeName string
+	Quiet    bool
 )
 
 func init() {
+	baseCmd.PersistentFlags().StringVarP(&NodeName, "render", "r", "", "node used for the variables in the template")
+	if err := baseCmd.RegisterFlagCompletionFunc("render", func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+		nodeDB, _ := node.New()
+		nodes, _ := nodeDB.FindAllNodes()
+		var node_names []string
+		for _, node := range nodes {
+			node_names = append(node_names, node.Id.Get())
+		}
+		return node_names, cobra.ShellCompDirectiveNoFileComp
+	}); err != nil {
+		log.Println(err)
+	}
+	baseCmd.PersistentFlags().BoolVarP(&Quiet, "quiet", "q", false, "do not print information if multiple, backup files are written")
 }
 
 // GetRootCommand returns the root cobra.Command for the application.

internal/pkg/overlay/datastructure.go

@@ -1,8 +1,14 @@
 package overlay
 
 import (
+	"net"
+	"os"
+	"strconv"
+	"time"
+
 	"github.com/hpcng/warewulf/internal/pkg/node"
 	"github.com/hpcng/warewulf/internal/pkg/warewulfconf"
+	"github.com/hpcng/warewulf/internal/pkg/wwlog"
 )
 
 /*
@@ -38,3 +44,105 @@ type TemplateStruct struct {
 	Nfs            warewulfconf.NfsConf
 	Warewulf       warewulfconf.WarewulfConf
 }
+
+/*
+Initialize an TemplateStruct with the given node.NodeInfo
+*/
+func InitStruct(nodeInfo node.NodeInfo) TemplateStruct {
+	var tstruct TemplateStruct
+	controller, err := warewulfconf.New()
+	if err != nil {
+		wwlog.Printf(wwlog.ERROR, "%s\n", err)
+		os.Exit(1)
+	}
+	nodeDB, err := node.New()
+	if err != nil {
+		wwlog.Printf(wwlog.ERROR, "%s\n", err)
+		os.Exit(1)
+	}
+	allNodes, err := nodeDB.FindAllNodes()
+	if err != nil {
+		wwlog.Printf(wwlog.ERROR, "%s\n", err)
+		os.Exit(1)
+	}
+
+	tstruct.Kernel = new(node.KernelConf)
+	tstruct.Ipmi = new(node.IpmiConf)
+	tstruct.Id = nodeInfo.Id.Get()
+	tstruct.Hostname = nodeInfo.Id.Get()
+	tstruct.Id = nodeInfo.Id.Get()
+	tstruct.Hostname = nodeInfo.Id.Get()
+	tstruct.ClusterName = nodeInfo.ClusterName.Get()
+	tstruct.Container = nodeInfo.ContainerName.Get()
+	tstruct.Kernel.Version = nodeInfo.Kernel.Override.Get()
+	tstruct.Kernel.Override = nodeInfo.Kernel.Override.Get()
+	tstruct.Kernel.Args = nodeInfo.Kernel.Args.Get()
+	tstruct.Init = nodeInfo.Init.Get()
+	tstruct.Root = nodeInfo.Root.Get()
+	tstruct.Ipmi.Ipaddr = nodeInfo.Ipmi.Ipaddr.Get()
+	tstruct.Ipmi.Netmask = nodeInfo.Ipmi.Netmask.Get()
+	tstruct.Ipmi.Port = nodeInfo.Ipmi.Port.Get()
+	tstruct.Ipmi.Gateway = nodeInfo.Ipmi.Gateway.Get()
+	tstruct.Ipmi.UserName = nodeInfo.Ipmi.UserName.Get()
+	tstruct.Ipmi.Password = nodeInfo.Ipmi.Password.Get()
+	tstruct.Ipmi.Interface = nodeInfo.Ipmi.Interface.Get()
+	tstruct.Ipmi.Write = nodeInfo.Ipmi.Write.Get()
+	tstruct.RuntimeOverlay = nodeInfo.RuntimeOverlay.Print()
+	tstruct.SystemOverlay = nodeInfo.SystemOverlay.Print()
+	tstruct.NetDevs = make(map[string]*node.NetDevs)
+	tstruct.Keys = make(map[string]string)
+	tstruct.Tags = make(map[string]string)
+	for devname, netdev := range nodeInfo.NetDevs {
+		var nd node.NetDevs
+		tstruct.NetDevs[devname] = &nd
+		tstruct.NetDevs[devname].Device = netdev.Device.Get()
+		tstruct.NetDevs[devname].Hwaddr = netdev.Hwaddr.Get()
+		tstruct.NetDevs[devname].Ipaddr = netdev.Ipaddr.Get()
+		tstruct.NetDevs[devname].Netmask = netdev.Netmask.Get()
+		tstruct.NetDevs[devname].Gateway = netdev.Gateway.Get()
+		tstruct.NetDevs[devname].Type = netdev.Type.Get()
+		tstruct.NetDevs[devname].OnBoot = netdev.OnBoot.Get()
+		tstruct.NetDevs[devname].Primary = netdev.Primary.Get()
+		mask := net.IPMask(net.ParseIP(netdev.Netmask.Get()).To4())
+		ipaddr := net.ParseIP(netdev.Ipaddr.Get()).To4()
+		netaddr := net.IPNet{IP: ipaddr, Mask: mask}
+		netPrefix, _ := net.IPMask(net.ParseIP(netdev.Netmask.Get()).To4()).Size()
+		tstruct.NetDevs[devname].Prefix = strconv.Itoa(netPrefix)
+		tstruct.NetDevs[devname].IpCIDR = netaddr.String()
+		tstruct.NetDevs[devname].Ipaddr6 = netdev.Ipaddr6.Get()
+		tstruct.NetDevs[devname].Tags = make(map[string]string)
+		for key, value := range netdev.Tags {
+			tstruct.NetDevs[devname].Tags[key] = value.Get()
+		}
+	}
+	// Backwards compatibility for templates using "Keys"
+	for keyname, key := range nodeInfo.Tags {
+		tstruct.Keys[keyname] = key.Get()
+	}
+	for keyname, key := range nodeInfo.Tags {
+		tstruct.Tags[keyname] = key.Get()
+	}
+	tstruct.AllNodes = allNodes
+	tstruct.Nfs = *controller.Nfs
+	tstruct.Dhcp = *controller.Dhcp
+	tstruct.Warewulf = *controller.Warewulf
+	tstruct.Ipaddr = controller.Ipaddr
+	tstruct.Ipaddr6 = controller.Ipaddr6
+	tstruct.Netmask = controller.Netmask
+	tstruct.Network = controller.Network
+	netaddrStruct := net.IPNet{IP: net.ParseIP(controller.Network), Mask: net.IPMask(net.ParseIP(controller.Netmask))}
+	tstruct.NetworkCIDR = netaddrStruct.String()
+	if controller.Ipaddr6 != "" {
+		tstruct.Ipv6 = true
+	} else {
+		tstruct.Ipv6 = false
+	}
+	hostname, _ := os.Hostname()
+	tstruct.BuildHost = hostname
+	dt := time.Now()
+	tstruct.BuildTime = dt.Format("01-02-2006 15:04:05 MST")
+	tstruct.BuildTimeUnix = strconv.FormatInt(dt.Unix(), 10)
+
+	return tstruct
+
+}

internal/pkg/overlay/overlay.go

@@ -6,19 +6,15 @@ import (
 	"fmt"
 	"io/fs"
 	"io/ioutil"
-	"net"
 	"os"
 	"path"
 	"path/filepath"
 	"regexp"
-	"strconv"
 	"strings"
 	"text/template"
-	"time"
 
 	"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/pkg/errors"
 )
@@ -199,106 +195,17 @@ func BuildOverlayIndir(nodeInfo node.NodeInfo, overlayNames []string, outputDir
 	if !util.IsDir(outputDir) {
 		return errors.Errorf("output must a be a directory: %s", outputDir)
 	}
-	controller, err := warewulfconf.New()
-	if err != nil {
-		wwlog.ErrorExc(err, "")
-		os.Exit(1)
-	}
-	nodeDB, err := node.New()
-	if err != nil {
-		wwlog.ErrorExc(err, "")
-		os.Exit(1)
-	}
-	allNodes, err := nodeDB.FindAllNodes()
-	if err != nil {
-		wwlog.ErrorExc(err, "")
-		os.Exit(1)
-	}
 
 	if !util.ValidString(strings.Join(overlayNames, ""), "^[a-zA-Z0-9-._:]+$") {
 		return errors.Errorf("overlay names contains illegal characters: %v", overlayNames)
 	}
-	wwlog.Verbose("Processing node/overlay: %s/%s", nodeInfo.Id.Get(), strings.Join(overlayNames, "-"))
+
-	var tstruct TemplateStruct
+	wwlog.Printf(wwlog.VERBOSE, "Processing node/overlay: %s/%s\n", nodeInfo.Id.Get(), strings.Join(overlayNames, "-"))
-	tstruct.Kernel = new(node.KernelConf)
-	tstruct.Ipmi = new(node.IpmiConf)
-	tstruct.Id = nodeInfo.Id.Get()
-	tstruct.Hostname = nodeInfo.Id.Get()
-	tstruct.ClusterName = nodeInfo.ClusterName.Get()
-	tstruct.Container = nodeInfo.ContainerName.Get()
-	tstruct.Kernel.Version = nodeInfo.Kernel.Override.Get()
-	tstruct.Kernel.Override = nodeInfo.Kernel.Override.Get()
-	tstruct.Kernel.Args = nodeInfo.Kernel.Args.Get()
-	tstruct.Init = nodeInfo.Init.Get()
-	tstruct.Root = nodeInfo.Root.Get()
-	tstruct.Ipmi.Ipaddr = nodeInfo.Ipmi.Ipaddr.Get()
-	tstruct.Ipmi.Netmask = nodeInfo.Ipmi.Netmask.Get()
-	tstruct.Ipmi.Port = nodeInfo.Ipmi.Port.Get()
-	tstruct.Ipmi.Gateway = nodeInfo.Ipmi.Gateway.Get()
-	tstruct.Ipmi.UserName = nodeInfo.Ipmi.UserName.Get()
-	tstruct.Ipmi.Password = nodeInfo.Ipmi.Password.Get()
-	tstruct.Ipmi.Interface = nodeInfo.Ipmi.Interface.Get()
-	tstruct.Ipmi.Write = nodeInfo.Ipmi.Write.Get()
-	tstruct.RuntimeOverlay = nodeInfo.RuntimeOverlay.Print()
-	tstruct.SystemOverlay = nodeInfo.SystemOverlay.Print()
-	tstruct.NetDevs = make(map[string]*node.NetDevs)
-	tstruct.Keys = make(map[string]string)
-	tstruct.Tags = make(map[string]string)
-	for devname, netdev := range nodeInfo.NetDevs {
-		var nd node.NetDevs
-		tstruct.NetDevs[devname] = &nd
-		tstruct.NetDevs[devname].Device = netdev.Device.Get()
-		tstruct.NetDevs[devname].Hwaddr = netdev.Hwaddr.Get()
-		tstruct.NetDevs[devname].Ipaddr = netdev.Ipaddr.Get()
-		tstruct.NetDevs[devname].Netmask = netdev.Netmask.Get()
-		tstruct.NetDevs[devname].Gateway = netdev.Gateway.Get()
-		tstruct.NetDevs[devname].Type = netdev.Type.Get()
-		tstruct.NetDevs[devname].OnBoot = netdev.OnBoot.Get()
-		tstruct.NetDevs[devname].Primary = netdev.Primary.Get()
-		mask := net.IPMask(net.ParseIP(netdev.Netmask.Get()).To4())
-		ipaddr := net.ParseIP(netdev.Ipaddr.Get()).To4()
-		netaddr := net.IPNet{IP: ipaddr, Mask: mask}
-		netPrefix, _ := net.IPMask(net.ParseIP(netdev.Netmask.Get()).To4()).Size()
-		tstruct.NetDevs[devname].Prefix = strconv.Itoa(netPrefix)
-		tstruct.NetDevs[devname].IpCIDR = netaddr.String()
-		tstruct.NetDevs[devname].Ipaddr6 = netdev.Ipaddr6.Get()
-		tstruct.NetDevs[devname].Tags = make(map[string]string)
-		for key, value := range netdev.Tags {
-			tstruct.NetDevs[devname].Tags[key] = value.Get()
-		}
-	}
-	// Backwards compatibility for templates using "Keys"
-	for keyname, key := range nodeInfo.Tags {
-		tstruct.Keys[keyname] = key.Get()
-	}
-	for keyname, key := range nodeInfo.Tags {
-		tstruct.Tags[keyname] = key.Get()
-	}
-	tstruct.AllNodes = allNodes
-	tstruct.Nfs = *controller.Nfs
-	tstruct.Dhcp = *controller.Dhcp
-	tstruct.Warewulf = *controller.Warewulf
-	tstruct.Ipaddr = controller.Ipaddr
-	tstruct.Ipaddr6 = controller.Ipaddr6
-	tstruct.Netmask = controller.Netmask
-	tstruct.Network = controller.Network
-	netaddrStruct := net.IPNet{IP: net.ParseIP(controller.Network), Mask: net.IPMask(net.ParseIP(controller.Netmask))}
-	tstruct.NetworkCIDR = netaddrStruct.String()
-	if controller.Ipaddr6 != "" {
-		tstruct.Ipv6 = true
-	} else {
-		tstruct.Ipv6 = false
-	}
-	hostname, _ := os.Hostname()
-	tstruct.BuildHost = hostname
-	dt := time.Now()
-	tstruct.BuildTime = dt.Format("01-02-2006 15:04:05 MST")
-	tstruct.BuildTimeUnix = strconv.FormatInt(dt.Unix(), 10)
 	for _, overlayName := range overlayNames {
 		wwlog.Verbose("Building overlay %s for node %s in %s", overlayName, nodeInfo.Id.Get(), outputDir)
 		overlaySourceDir := OverlaySourceDir(overlayName)
-		wwlog.Debug("Starting to build overlay %s\nChanging directory to OverlayDir: %s", overlayName, overlaySourceDir)
+		wwlog.Printf(wwlog.DEBUG, "Starting to build overlay %s\nChanging directory to OverlayDir: %s\n", overlayName, overlaySourceDir)
-		err = os.Chdir(overlaySourceDir)
+		err := os.Chdir(overlaySourceDir)
 		if err != nil {
 			return errors.Wrap(err, "could not change directory to overlay dir")
 		}
@@ -330,48 +237,21 @@ func BuildOverlayIndir(nodeInfo node.NodeInfo, overlayNames []string, outputDir
 				wwlog.Debug("Created directory in overlay: %s", location)
 
 			} else if filepath.Ext(location) == ".ww" {
+				tstruct := InitStruct(nodeInfo)
 				tstruct.BuildSource = path.Join(overlaySourceDir, location)
 				wwlog.Verbose("Evaluating overlay template file: %s", location)
 				destFile := strings.TrimSuffix(location, ".ww")
-				backupFile := true
+
-				writeFile := true
+				buffer, backupFile, writeFile, err := RenderTemplateFile(location, tstruct)
-				tmpl, err := template.New(path.Base(location)).Option("missingkey=default").Funcs(template.FuncMap{
-					// TODO: Fix for missingkey=zero
-					"Include":      templateFileInclude,
-					"IncludeFrom":  templateContainerFileInclude,
-					"IncludeBlock": templateFileBlock,
-					"inc":          func(i int) int { return i + 1 },
-					"dec":          func(i int) int { return i - 1 },
-					"file":         func(str string) string { return fmt.Sprintf("{{ /* file \"%s\" */ }}", str) },
-					"abort": func() string {
-						wwlog.Debug("abort file called in %s", location)
-						writeFile = false
-						return ""
-					},
-					"nobackup": func() string {
-						wwlog.Debug("not backup for %s", location)
-						backupFile = false
-						return ""
-					},
-					"split": func(s string, d string) []string {
-						return strings.Split(s, d)
-					},
-					// }).ParseGlob(path.Join(OverlayDir, destFile+".ww*"))
-				}).ParseGlob(location)
 				if err != nil {
-					return errors.Wrap(err, "could not parse template "+location)
+					return errors.Wrap(err, fmt.Sprintf("Failed to render template %s", location))
-				}
-				var buffer bytes.Buffer
-				err = tmpl.Execute(&buffer, tstruct)
-				if err != nil {
-					return errors.Wrap(err, "could not execute template")
 				}
 				if writeFile {
 					destFileName := destFile
 					var fileBuffer bytes.Buffer
 					// search for magic file name comment
 					fileScanner := bufio.NewScanner(bytes.NewReader(buffer.Bytes()))
-					fileScanner.Split(scanLines)
+					fileScanner.Split(ScanLines)
 					reg := regexp.MustCompile(`.*{{\s*/\*\s*file\s*["'](.*)["']\s*\*/\s*}}.*`)
 					foundFileComment := false
 					for fileScanner.Scan() {
@@ -475,8 +355,55 @@ func carefulWriteBuffer(destFile string, buffer bytes.Buffer, backupFile bool, p
 	return err
 }
 
+/*
+Parses the template with the given filename, variables must be in data. Returns the
+parsed template as bytes.Buffer, and the bool variables for backupFile and writeFile.
+If something goes wrong an error is returned.
+*/
+func RenderTemplateFile(fileName string, data TemplateStruct) (
+	buffer bytes.Buffer,
+	backupFile bool,
+	writeFile bool,
+	err error) {
+	backupFile = true
+	writeFile = true
+	tmpl, err := template.New(path.Base(fileName)).Option("missingkey=default").Funcs(template.FuncMap{
+		// TODO: Fix for missingkey=zero
+		"Include":      templateFileInclude,
+		"IncludeFrom":  templateContainerFileInclude,
+		"IncludeBlock": templateFileBlock,
+		"inc":          func(i int) int { return i + 1 },
+		"dec":          func(i int) int { return i - 1 },
+		"file":         func(str string) string { return fmt.Sprintf("{{ /* file \"%s\" */ }}", str) },
+		"abort": func() string {
+			wwlog.Printf(wwlog.DEBUG, "abort file called in %s\n", fileName)
+			writeFile = false
+			return ""
+		},
+		"nobackup": func() string {
+			wwlog.Printf(wwlog.DEBUG, "not backup for %s\n", fileName)
+			backupFile = false
+			return ""
+		},
+		"split": func(s string, d string) []string {
+			return strings.Split(s, d)
+		},
+		// }).ParseGlob(path.Join(OverlayDir, destFile+".ww*"))
+	}).ParseGlob(fileName)
+	if err != nil {
+		err = errors.Wrap(err, "could not parse template "+fileName)
+		return
+	}
+	err = tmpl.Execute(&buffer, data)
+	if err != nil {
+		err = errors.Wrap(err, "could not execute template")
+		return
+	}
+	return
+}
+
 // Simple version of ScanLines, but include the line break
-func scanLines(data []byte, atEOF bool) (advance int, token []byte, err error) {
+func ScanLines(data []byte, atEOF bool) (advance int, token []byte, err error) {
 	if atEOF && len(data) == 0 {
 		return 0, nil, nil
 	}