engine: util, resources: virt: Clean up virt resource

Do some cleanups which were long overdue.

engine/util/cmp.go

@@ -0,0 +1,37 @@
+// Mgmt
+// Copyright (C) 2013-2018+ James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package util
+
+import (
+	"fmt"
+)
+
+// StrListCmp compares two lists of strings. If they are not the same length or
+// do not contain identical strings in the same order, then this errors.
+func StrListCmp(x, y []string) error {
+	if len(x) != len(y) {
+		return fmt.Errorf("length differs")
+	}
+	for i := range x {
+		if x[i] != y[i] {
+			return fmt.Errorf("the elements at position %d differed", i)
+		}
+	}
+
+	return nil
+}