linter: upgrade golangci-lint to v2

.golangci.yml

@@ -1,16 +1,8 @@
+version: "2"
 run:
-  # timeout for analysis
-  timeout: 4m
-
   # Linting uses a lot of memory. Keep it under control by only running a single
   # worker.
   concurrency: 1
-
-linters-settings:
-  gofmt:
-    # simplify code: gofmt with `-s` option, true by default
-    simplify: true
-
 linters:
 
   # Specify an enabled list of linters rather than a disabled list because
@@ -19,27 +11,41 @@ linters:
     - bodyclose
     - copyloopvar
     - dupl
-    - errcheck
     - goconst
     - gocritic
     - gocyclo
-    - gofmt
-    - goimports
-    - gosimple
-    - govet
-    - ineffassign
     - misspell
     - nakedret
     - prealloc
     - staticcheck
-    - stylecheck
-    - typecheck
     - unconvert
     - unparam
-    - unused
-
-issues:
-  exclude-rules:
-    - path: internal/test
-      linters:
-        - goconst
+  exclusions:
+    generated: lax
+    presets:
+      - comments
+      - common-false-positives
+      - legacy
+      - std-error-handling
+    rules:
+      - linters:
+          - goconst
+        path: internal/test
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
+formatters:
+  enable:
+    - gofmt
+    - goimports
+  settings:
+    gofmt:
+      # simplify code: gofmt with `-s` option, true by default
+      simplify: true
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$

aperturedb/interface.go

@@ -165,7 +165,7 @@ func (t *TransactionExecutor[Q]) ExecTx(ctx context.Context,
 
 	for i := 0; i < t.opts.numRetries; i++ {
 		// Create the db transaction.
-		tx, err := t.BatchedQuerier.BeginTx(ctx, txOptions)
+		tx, err := t.BeginTx(ctx, txOptions)
 		if err != nil {
 			return err
 		}

aperturedb/sqlite.go

@@ -167,7 +167,7 @@ func NewTestSqliteDB(t *testing.T) *SqliteStore {
 	require.NoError(t, err)
 
 	t.Cleanup(func() {
-		require.NoError(t, sqlDB.DB.Close())
+		require.NoError(t, sqlDB.Close())
 	})
 
 	return sqlDB

challenger/lnd.go

@@ -366,6 +366,7 @@ func (l *LndChallenger) VerifyInvoiceStatus(hash lntypes.Hash,
 		// Block here until our condition is met or the allowed time is
 		// up. The Wait() will return whenever a signal is broadcast.
 		invoiceState, hasInvoice = l.invoiceStates[hash]
+		//nolint:staticcheck
 		for !(hasInvoice && invoiceState == state) && !timeoutReached {
 			l.invoicesCond.Wait()
 

internal/test/lnd_services_mock.go

@@ -81,9 +81,9 @@ func NewMockLnd() *LndMockServices {
 	// Also simulate the cached info that is loaded on startup.
 	info, _ := lightningClient.GetInfo(context.Background())
 	version, _ := versioner.GetVersion(context.Background())
-	lnd.LndServices.NodeAlias = info.Alias
+	lnd.NodeAlias = info.Alias
 	lnd.LndServices.NodePubkey = info.IdentityPubkey
-	lnd.LndServices.Version = version
+	lnd.Version = version
 
 	lnd.WaitForFinished = func() {
 		chainNotifier.WaitForFinished()

onion_store.go

@@ -38,7 +38,7 @@ func newOnionStore(client *clientv3.Client) *onionStore {
 
 // StorePrivateKey stores the given private key.
 func (s *onionStore) StorePrivateKey(privateKey []byte) error {
-	_, err := s.Client.Put(context.Background(), onionPath, string(privateKey))
+	_, err := s.Put(context.Background(), onionPath, string(privateKey))
 	return err
 }
 
@@ -58,6 +58,6 @@ func (s *onionStore) PrivateKey() ([]byte, error) {
 
 // DeletePrivateKey securely removes the private key from the store.
 func (s *onionStore) DeletePrivateKey() error {
-	_, err := s.Client.Delete(context.Background(), onionPath)
+	_, err := s.Delete(context.Background(), onionPath)
 	return err
 }

proxy/service.go

@@ -200,12 +200,12 @@ func prepareServices(services []*Service) error {
 
 			// There are two supported formats to encode the file
 			// content in: hex and base64.
-			switch {
-			case prefix == filePrefixHex:
+			switch prefix {
+			case filePrefixHex:
 				newValue := hex.EncodeToString(bytes)
 				service.Headers[key] = newValue
 
-			case prefix == filePrefixBase64:
+			case filePrefixBase64:
 				newValue := base64.StdEncoding.EncodeToString(
 					bytes,
 				)

tools/Dockerfile

@@ -1,17 +1,18 @@
-FROM golang:1.24.6-bookworm
+FROM golang:1.24.6
 
-RUN apt-get update && apt-get install -y git
-ENV GOCACHE=/tmp/build/.cache
-ENV GOMODCACHE=/tmp/build/.modcache
-ENV GOFLAGS="-buildvcs=false"
+RUN apt-get update && apt-get install -y --no-install-recommends git ca-certificates \
+ && rm -rf /var/lib/apt/lists/*
+
+ENV CGO_ENABLED=0 \
+    GOCACHE=/tmp/build/.cache \
+    GOMODCACHE=/tmp/build/.modcache \
+    GOFLAGS="-buildvcs=false"
 
 COPY . /tmp/tools
 
-RUN cd /tmp \
-  && mkdir -p /tmp/build/.cache \
-  && mkdir -p /tmp/build/.modcache \
-  && cd /tmp/tools \
-  && go install -trimpath github.com/golangci/golangci-lint/cmd/golangci-lint \
-  && chmod -R 777 /tmp/build/
+RUN mkdir -p /tmp/build/.cache /tmp/build/.modcache \
+ && cd /tmp/tools \
+ && go install -trimpath github.com/golangci/golangci-lint/v2/cmd/golangci-lint \
+ && chmod -R 777 /tmp/build/
 
-WORKDIR /build
+WORKDIR /build