chore(lint): update to golangci-lint v2.6.0 (#7645)

Update to the latest golangci-lint version and use built-in modernize
linter, instead of a custom CI step.

Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>

.github/workflows/golangci-lint.yml

@@ -20,6 +20,4 @@ jobs:
       - name: golangci-lint
         uses: golangci/golangci-lint-action@4afd733a84b1f43292c63897423277bb7f4313a9  # v8.0.0
         with:
-          version: v2.5.0
+          version: v2.6.0
-      - name: modernize
-        run: go run golang.org/x/tools/gopls/internal/analysis/modernize/cmd/modernize@2e31135b736b96cd609904370c71563ce5447826 -diff -test ./... # v0.20.0

.golangci.yml

@@ -14,6 +14,7 @@ linters:
     - govet
     - ineffassign
     - intrange
+    - modernize
     - nakedret
     - nolintlint
     - perfsprint
@@ -42,6 +43,9 @@ linters:
     govet:
       enable:
         - nilness
+    modernize:
+      disable:
+        - reflecttypefor
     perfsprint:
       error-format: false
     revive:

plugin/rewrite/cname_target.go

@@ -44,8 +44,8 @@ func (r *cnameTargetRule) getFromAndToTarget(inputCName string) (from string, to
 			return inputCName, r.paramToTarget + after
 		}
 	case SuffixMatch:
-		if strings.HasSuffix(inputCName, r.paramFromTarget) {
+		if before, ok := strings.CutSuffix(inputCName, r.paramFromTarget); ok {
-			return inputCName, strings.TrimSuffix(inputCName, r.paramFromTarget) + r.paramToTarget
+			return inputCName, before + r.paramToTarget
 		}
 	case SubstringMatch:
 		if strings.Contains(inputCName, r.paramFromTarget) {

plugin/rewrite/name.go

@@ -81,8 +81,8 @@ func newSuffixStringRewriter(orig, replacement string) stringRewriter {
 }
 
 func (r *suffixStringRewriter) rewriteString(src string) string {
-	if strings.HasSuffix(src, r.suffix) {
+	if before, ok := strings.CutSuffix(src, r.suffix); ok {
-		return strings.TrimSuffix(src, r.suffix) + r.replacement
+		return before + r.replacement
 	}
 	return src
 }
@@ -234,8 +234,8 @@ func newSuffixNameRule(nextAction string, auto bool, suffix, replacement string,
 }
 
 func (rule *suffixNameRule) Rewrite(ctx context.Context, state request.Request) (ResponseRules, Result) {
-	if strings.HasSuffix(state.Name(), rule.suffix) {
+	if before, ok := strings.CutSuffix(state.Name(), rule.suffix); ok {
-		state.Req.Question[0].Name = strings.TrimSuffix(state.Name(), rule.suffix) + rule.replacement
+		state.Req.Question[0].Name = before + rule.replacement
 		return rule.responseRuleFor(state)
 	}
 	return nil, RewriteIgnored