Upgrade to golangci-lint v2 for improved linting

Noteworthy changes in golangci-lint v2:

* New config format (migrated with `migrate` command)
* Default timeout is now 0 instead of 1 minute.

Also fixes issues reported by golangci-lint v2:

* Same error string capitalization. Details:
    * Also changed two asserts in a test
    * Also removed "Error:" prefix
* Prefer embedded field
* Lift `break` into loop condition
* Prefer tagged switch in some test files

Author: jorbaum

scripts/subtests/lint

@@ -9,7 +9,7 @@ set +e
 golangci_lint_executable=$(which golangci-lint)
 set -e
 if [ -z "${golangci_lint_executable}" ] || [ ! -x "${golangci_lint_executable}" ]; then
-  go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
+  go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@latest
 fi
 
 pushd "${SCRIPT_DIR}/../../src" > /dev/null

src/.golangci.yml

@@ -1,3 +1,5 @@
+version: "2"
+
 run:
   # Timeout for analysis, e.g. 30s, 5m.
   # Default: 1m
@@ -11,9 +13,28 @@ linters:
     - gocyclo
     # Inspects source code for security problems.
     - gosec
+  exclusions:
+    generated: lax
+    presets:
+      - comments
+      - common-false-positives
+      - legacy
+      - std-error-handling
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
 
 issues:
   # Disable max issues per linter.
   max-issues-per-linter: 0
   # Disable max same issues.
   max-same-issues: 0
+
+formatters:
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$

src/integration_tests/fakes/doppler.go

@@ -9,7 +9,7 @@ import (
 	"code.cloudfoundry.org/loggregator-release/src/testservers"
 	"google.golang.org/grpc"
 
-	. "github.com/onsi/gomega"
+	. "github.com/onsi/gomega" //nolint:staticcheck
 )
 
 func DopplerEgressV1Client(addr string) (func(), plumbing.DopplerClient) {

src/integration_tests/router/router_suite_test.go

@@ -171,8 +171,8 @@ func primePumpV2(ingressClient loggregator_v2.Ingress_SenderClient, subscribeCli
 	Expect(err).ToNot(HaveOccurred())
 }
 
-var ErrorMissingOrigin = errors.New("Event not emitted due to missing origin information")
-var ErrorUnknownEventType = errors.New("Cannot create envelope for unknown event type")
+var ErrorMissingOrigin = errors.New("event not emitted due to missing origin information")
+var ErrorUnknownEventType = errors.New("cannot create envelope for unknown event type")
 
 func Wrap(event events.Event, origin string) (*events.Envelope, error) {
 	if origin == "" {

src/integration_tests/trafficcontroller/fake_uaa_server_test.go

@@ -22,7 +22,8 @@ func (h *FakeUaaHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	token := r.FormValue("token")
 
-	if token == "iAmAnAdmin" {
+	switch token {
+	case "iAmAnAdmin":
 		authData := map[string]interface{}{
 			"scope": []string{
 				"doppler.firehose",
@@ -31,7 +32,7 @@ func (h *FakeUaaHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 		marshaled, _ := json.Marshal(authData)
 		_, _ = w.Write(marshaled)
-	} else if token == "iAmNotAnAdmin" {
+	case "iAmNotAnAdmin":
 		authData := map[string]interface{}{
 			"scope": []string{
 				"uaa.not-admin",
@@ -40,13 +41,13 @@ func (h *FakeUaaHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 		marshaled, _ := json.Marshal(authData)
 		_, _ = w.Write(marshaled)
-	} else if token == "expiredToken" {
+	case "expiredToken":
 		w.WriteHeader(http.StatusBadRequest)
 		_, _ = w.Write([]byte("{\"error\":\"invalid_token\",\"error_description\":\"Token has expired\"}"))
-	} else if token == "invalidToken" {
+	case "invalidToken":
 		w.WriteHeader(http.StatusBadRequest)
 		_, _ = w.Write([]byte("{\"invalidToken\":\"invalid_token\",\"error_description\":\"Invalid token (could not decode): invalidToken\"}"))
-	} else {
+	default:
 		w.WriteHeader(http.StatusInternalServerError)
 	}
 

src/metricemitter/counter.go

@@ -35,7 +35,7 @@ func NewCounter(name, sourceID string, opts ...MetricOption) *Counter {
 		name:     name,
 		sourceID: sourceID,
 	}
-	m.Tagged.tags = make(map[string]*loggregator_v2.Value)
+	m.tags = make(map[string]*loggregator_v2.Value)
 
 	for _, opt := range opts {
 		opt(m.Tagged)

src/metricemitter/gauge.go

@@ -27,7 +27,7 @@ func NewGauge(name, unit, sourceID string, opts ...MetricOption) *Gauge {
 		unit:     unit,
 		sourceID: sourceID,
 	}
-	m.Tagged.tags = make(map[string]*loggregator_v2.Value)
+	m.tags = make(map[string]*loggregator_v2.Value)
 
 	for _, opt := range opts {
 		opt(m.Tagged)

src/router/internal/server/v1/doppler_server.go

@@ -104,11 +104,7 @@ func (m *DopplerServer) sendData(req *plumbing.SubscriptionRequest, sender sende
 	var done int64
 	go m.monitorContext(sender.Context(), &done)
 
-	for {
-		if atomic.LoadInt64(&done) > 0 {
-			break
-		}
-
+	for atomic.LoadInt64(&done) <= 0 {
 		data, ok := d.TryNext()
 		if !ok {
 			time.Sleep(10 * time.Millisecond)

src/router/internal/sinks/message_router_test.go

@@ -56,8 +56,8 @@ var _ = Describe("Message Router", func() {
 	})
 })
 
-var errorMissingOrigin = errors.New("Event not emitted due to missing origin information")
-var errorUnknownEventType = errors.New("Cannot create envelope for unknown event type")
+var errorMissingOrigin = errors.New("event not emitted due to missing origin information")
+var errorUnknownEventType = errors.New("cannot create envelope for unknown event type")
 
 func wrap(event events.Event, origin string) (*events.Envelope, error) {
 	if origin == "" {

src/testservers/router.go

@@ -8,8 +8,8 @@ import (
 	envstruct "code.cloudfoundry.org/go-envstruct"
 	"code.cloudfoundry.org/loggregator-release/src/router/app"
 
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
+	. "github.com/onsi/ginkgo/v2" //nolint:staticcheck
+	. "github.com/onsi/gomega"    //nolint:staticcheck
 	"github.com/onsi/gomega/gexec"
 )