Worker node upgrade chain

clitools/pkg/node/prereqs.go

@@ -203,6 +203,26 @@ func versionEq(a, b string) bool {
 	return normalizeKubeVersion(a) == normalizeKubeVersion(b)
 }
 
+func versionLt(a, b string) (bool, error) {
+	av, err := parseKubeVersion(a)
+	if err != nil {
+		return false, err
+	}
+
+	bv, err := parseKubeVersion(b)
+	if err != nil {
+		return false, err
+	}
+
+	if av.Major != bv.Major {
+		return av.Major < bv.Major, nil
+	}
+	if av.Minor != bv.Minor {
+		return av.Minor < bv.Minor, nil
+	}
+	return av.Patch < bv.Patch, nil
+}
+
 func normalizeKubeVersion(v string) string {
 	v = strings.TrimSpace(v)
 	if v == "" {