Add BuildTimeUnix containing Unix time (seconds since epoch).

internal/pkg/overlay/datastructure.go

@@ -26,6 +26,7 @@ type TemplateStruct struct {
 	AllNodes       []node.NodeInfo
 	BuildHost      string
 	BuildTime      string
+	BuildTimeUnix  string
 	BuildSource    string
 	Ipaddr         string
 	Ipaddr6        string

internal/pkg/overlay/overlay.go

@@ -300,6 +300,7 @@ func BuildOverlayIndir(nodeInfo node.NodeInfo, overlayNames []string, outputDir
 	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.Printf(wwlog.VERBOSE, "Building overlay %s for node %s in %s\n", overlayName, nodeInfo.Id.Get(), outputDir)
 		overlaySourceDir := OverlaySourceDir(overlayName)