First pass at a rework of the overlay subsystem in Warewulf

internal/pkg/overlay/funcmap.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"github.com/hpcng/warewulf/internal/pkg/container"
+	"github.com/hpcng/warewulf/internal/pkg/util"
 	"github.com/hpcng/warewulf/internal/pkg/wwlog"
 )
 
@@ -19,15 +20,15 @@ func templateFileInclude(path string) string {
 }
 
 func templateContainerFileInclude(containername string, filepath string) string {
-	wwlog.Printf(wwlog.DEBUG, "Including VNFS file into template: %s: %s\n", containername, filepath)
+	wwlog.Printf(wwlog.VERBOSE, "Including file from Container into template: %s:%s\n", containername, filepath)
 
 	if containername == "" {
-		wwlog.Printf(wwlog.WARN, "VNFS not set for template import request: %s: %s\n", containername, filepath)
+		wwlog.Printf(wwlog.WARN, "Container is not defined for node: %s\n", filepath)
 		return ""
 	}
 
 	if !container.ValidSource(containername) {
-		wwlog.Printf(wwlog.WARN, "Template required VNFS does not exist: %s\n", containername)
+		wwlog.Printf(wwlog.WARN, "Template requires file(s) from non-existant container: %s:%s\n", containername, filepath)
 		return ""
 	}
 
@@ -35,10 +36,15 @@ func templateContainerFileInclude(containername string, filepath string) string
 
 	wwlog.Printf(wwlog.DEBUG, "Including file from container: %s:%s\n", containerDir, filepath)
 
+	if !util.IsFile(path.Join(containerDir, filepath)) {
+		wwlog.Printf(wwlog.WARN, "Requested file from container does not exist: %s:%s\n", containername, filepath)
+		return ""
+	}
+
 	content, err := ioutil.ReadFile(path.Join(containerDir, filepath))
 
 	if err != nil {
-		wwlog.Printf(wwlog.ERROR, "Template include: %s\n", err)
+		wwlog.Printf(wwlog.ERROR, "Template include failed: %s\n", err)
 	}
 	return strings.TrimSuffix(string(content), "\n")
 }