Introduce golangci lint

.github/workflows/ci.yaml

@@ -4,8 +4,6 @@ on:
   push:
     branches:
     - 'main'
-env:
-  cache-version: 1
 jobs:
   validation:
     name: Validation
@@ -17,17 +15,7 @@ jobs:
         go-version-file: go.mod
     - name: Setup Aqua
       uses: ./.github/actions/setup-aqua
-    - name: Cache Tools
-      id: cache-tools
-      uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
-      with:
-        path: |
-          bin
-          include
-        key: cache-${{ env.cache-version }}-${{ hashFiles('go.mod') }}-${{ hashFiles('Makefile') }}
-    - run: make setup
-      if: steps.cache-tools.outputs.cache-hit != 'true'
-    - run: make validate
+    - run: make lint
     - run: make check-generate
   build:
     name: build

.golangci.yml

@@ -0,0 +1,46 @@
+version: "2"
+run:
+  allow-parallel-runners: true
+linters:
+  default: none
+  enable:
+    - copyloopvar
+    - errcheck
+    - goconst
+    - gocyclo
+    - govet
+    - ineffassign
+    - modernize
+    - misspell
+    - nakedret
+    - staticcheck
+    - unconvert
+    - unparam
+    - unused
+    - nilerr
+  settings:
+    govet:
+      disable:
+        - fieldalignment
+        - shadow
+      enable-all: true
+    modernize:
+      disable:
+        - omitzero
+  exclusions:
+    rules:
+      - path: (.+)(_test\.go|test_(.+)\.go)
+        linters:
+        - noctx
+        - errcheck
+        - goconst
+        - unparam
+      # MySQL privilege names in the user definitions naturally repeat
+      # across users; they are clearer as literals than as constants.
+      - path: server/initialize\.go
+        linters:
+        - goconst
+formatters:
+  enable:
+    - gofmt
+    - goimports

Makefile

@@ -1,16 +1,5 @@
 MYSQL_VERSION = 8.4.4
 
-# For Go
-GOOS := $(shell go env GOOS)
-GOARCH := $(shell go env GOARCH)
-
-# Get the currently used golang install path (in GOPATH/bin, unless GOBIN is set)
-ifeq (,$(shell go env GOBIN))
-GOBIN=$(shell go env GOPATH)/bin
-else
-GOBIN=$(shell go env GOBIN)
-endif
-
 GO_FILES := $(shell find . -name '*.go' -print)
 
 PROTOC := protoc
@@ -22,18 +11,14 @@ all: build/moco-agent
 aqua-install:
 	aqua install
 
+.PHONY: lint
+lint: aqua-install
+	@golangci-lint run --timeout 5m
+
 .PHONY: pinact
 pinact:
 	pinact run -update -min-age 7 -verify
 
-.PHONY: validate
-validate: setup aqua-install
-	test -z "$$(gofmt -s -l . | tee /dev/stderr)"
-	staticcheck ./...
-	test -z "$$(custom-checker -restrictpkg.packages=html/template,log $$(go list -tags='$(GOTAGS)' ./... ) 2>&1 | tee /dev/stderr)"
-	go build ./...
-	go vet ./...
-
 .PHONY: check-generate
 check-generate:
 	$(MAKE) proto
@@ -61,21 +46,6 @@ proto/agentrpc_grpc.pb.go: proto/agentrpc.proto
 docs/agentrpc.md: proto/agentrpc.proto
 	$(PROTOC) --doc_out=docs --doc_opt=markdown,$@ $<
 
-.PHONY: setup
-setup: custom-checker staticcheck
-
-.PHONY: staticcheck
-staticcheck:
-	if ! which staticcheck >/dev/null; then \
-		env GOFLAGS= go install honnef.co/go/tools/cmd/staticcheck@latest; \
-	fi
-
-.PHONY: custom-checker
-custom-checker:
-	if ! which custom-checker >/dev/null; then \
-		env GOFLAGS= go install github.com/cybozu-go/golang-custom-analyzer/cmd/custom-checker@latest; \
-	fi
-
 .PHONY: clean
 clean:
 	rm -rf build

aqua-checksums.json

@@ -25,6 +25,36 @@
       "checksum": "434D2FC10049A39FE069C6370CD45C1330871B01A4500FAC970FCD6BFB1D1FE9",
       "algorithm": "sha256"
     },
+    {
+      "id": "github_release/github.com/golangci/golangci-lint/v2.12.2/golangci-lint-2.12.2-darwin-amd64.tar.gz",
+      "checksum": "F6F06D94B6241521C53D15450C5209B028270BF966F842AFB11C030C79F5BC16",
+      "algorithm": "sha256"
+    },
+    {
+      "id": "github_release/github.com/golangci/golangci-lint/v2.12.2/golangci-lint-2.12.2-darwin-arm64.tar.gz",
+      "checksum": "A9C54498731B3128F79E090BE6110F3E5FFFCCC617B08142ED244D4126C73F29",
+      "algorithm": "sha256"
+    },
+    {
+      "id": "github_release/github.com/golangci/golangci-lint/v2.12.2/golangci-lint-2.12.2-linux-amd64.tar.gz",
+      "checksum": "8DF580D2670FED8FA984AAC0507099AF8DF275E665215F5C7A2AE3943893A553",
+      "algorithm": "sha256"
+    },
+    {
+      "id": "github_release/github.com/golangci/golangci-lint/v2.12.2/golangci-lint-2.12.2-linux-arm64.tar.gz",
+      "checksum": "44CD40A8C76C86755375ADFEEA52CFD3533CB43D7BD647771E0AE065E166DF3A",
+      "algorithm": "sha256"
+    },
+    {
+      "id": "github_release/github.com/golangci/golangci-lint/v2.12.2/golangci-lint-2.12.2-windows-amd64.zip",
+      "checksum": "BD42E3EBC8CB4ECECB86941983BAAF1DC221BBB04D838E94CE63B49CC91E02BB",
+      "algorithm": "sha256"
+    },
+    {
+      "id": "github_release/github.com/golangci/golangci-lint/v2.12.2/golangci-lint-2.12.2-windows-arm64.zip",
+      "checksum": "947B9A5BF762D465710B376C156F0184ABB2168378B0826AF1899E0EE7183742",
+      "algorithm": "sha256"
+    },
     {
       "id": "github_release/github.com/grpc/grpc-go/cmd/protoc-gen-go-grpc/v1.5.1/protoc-gen-go-grpc.v1.5.1.darwin.amd64.tar.gz",
       "checksum": "C12C259D59C8B451F24B6ABDAD6D055FD0884C5268B7247FD7E5EC9D2432D1F1",

aqua.yaml

@@ -15,4 +15,5 @@ packages:
 - name: protocolbuffers/protobuf-go/protoc-gen-go@v1.36.11
 - name: grpc/grpc-go/protoc-gen-go-grpc@cmd/protoc-gen-go-grpc/v1.6.1
 - name: pseudomuto/protoc-gen-doc@v1.5.1
+- name: golangci/golangci-lint@v2.12.2
 - name: suzuki-shunsuke/pinact@v4.1.1

cmd/cp/main.go

@@ -31,7 +31,7 @@ func run() error {
 		return fmt.Errorf("unable to open source file %q: %w", os.Args[1], err)
 	}
 
-	defer sf.Close()
+	defer func() { _ = sf.Close() }()
 
 	fi, err := sf.Stat()
 	if err != nil {
@@ -52,7 +52,7 @@ func run() error {
 		return fmt.Errorf("unable to create destination file %q: %w", os.Args[1], err)
 	}
 
-	defer df.Close()
+	defer func() { _ = df.Close() }()
 
 	if _, err = io.Copy(df, sf); err != nil {
 		return fmt.Errorf("unable to copy %q to %q: %w", os.Args[1], os.Args[2], err)

cmd/moco-agent/cmd/root.go

@@ -61,7 +61,7 @@ var config struct {
 
 type mysqlLogger struct{}
 
-func (l mysqlLogger) Print(v ...interface{}) {}
+func (l mysqlLogger) Print(v ...any) {}
 
 var rootCmd = &cobra.Command{
 	Use:   "moco-agent",
@@ -72,17 +72,16 @@ var rootCmd = &cobra.Command{
 		if err != nil {
 			return err
 		}
-		defer zapLogger.Sync()
+		defer func() { _ = zapLogger.Sync() }()
 		rLogger := zapr.NewLogger(zapLogger)
 
 		// Read required values for agent from ENV
 		podName := os.Getenv(mocoagent.PodNameEnvKey)
 		if podName == "" {
 			return fmt.Errorf("%s is empty", mocoagent.PodNameEnvKey)
 		}
-		index := -1
 		fields := strings.Split(podName, "-")
-		index, _ = strconv.Atoi(fields[len(fields)-1])
+		index, _ := strconv.Atoi(fields[len(fields)-1])
 		agentPassword := os.Getenv(mocoagent.AgentPasswordEnvKey)
 		if agentPassword == "" {
 			return fmt.Errorf("%s is empty", mocoagent.AgentPasswordEnvKey)
@@ -116,9 +115,11 @@ var rootCmd = &cobra.Command{
 		if err != nil {
 			return err
 		}
-		defer agent.CloseDB()
+		defer func() { _ = agent.CloseDB() }()
 
-		mysql.SetLogger(mysqlLogger{})
+		if err := mysql.SetLogger(mysqlLogger{}); err != nil {
+			return err
+		}
 
 		registry := prometheus.DefaultRegisterer
 		metrics.Init(registry, clusterName, index)
@@ -290,7 +291,7 @@ func initializeMySQLForMOCO(ctx context.Context, socketPath string, logger logr.
 		}
 	}
 
-	defer db.Close()
+	defer func() { _ = db.Close() }()
 
 	return server.Init(ctx, db, socketPath)
 }

cmd/moco-init/main.go

@@ -158,7 +158,7 @@ func initMySQL(mysqld string) error {
 	if err != nil {
 		return err
 	}
-	defer f.Close()
+	defer func() { _ = f.Close() }()
 
 	if err := unix.Syncfs(int(f.Fd())); err != nil {
 		return fmt.Errorf("failed to sync fs: %w", err)
@@ -172,7 +172,7 @@ func initMySQL(mysqld string) error {
 	if err != nil {
 		return err
 	}
-	defer g.Close()
+	defer func() { _ = g.Close() }()
 	return g.Sync()
 }
 
@@ -270,7 +270,7 @@ func createConf() error {
 	if err != nil {
 		return fmt.Errorf("failed to create my.cnf file: %w", err)
 	}
-	defer f.Close()
+	defer func() { _ = f.Close() }()
 
 	if err := tmpl.Execute(f, v); err != nil {
 		return err

server/clone.go

@@ -68,7 +68,7 @@ func (a *Agent) Clone(ctx context.Context, req *proto.CloneRequest) error {
 	if err != nil {
 		return fmt.Errorf("failed to connect to mysqld through %s: %w", a.mysqlSocketPath, err)
 	}
-	defer cloneDB.Close()
+	defer func() { _ = cloneDB.Close() }()
 
 	logger.Info("start cloning instance", "donor", donorAddr)
 	_, err = cloneDB.Exec(`CLONE INSTANCE FROM ?@?:? IDENTIFIED BY ?`, req.User, req.Host, req.Port, req.Password)
@@ -100,7 +100,7 @@ func (a *Agent) Clone(ctx context.Context, req *proto.CloneRequest) error {
 		logger.Error(err, "failed to connect to mysqld after bootstrap")
 		return err
 	}
-	defer initDB.Close()
+	defer func() { _ = initDB.Close() }()
 
 	if err := InitExternal(context.Background(), initDB); err != nil {
 		logger.Error(err, "failed to initialize after clone")
@@ -123,7 +123,7 @@ func waitBootstrap(user, password, socket string, timeout time.Duration, logger
 
 		db, err := GetMySQLConnLocalSocket(user, password, socket)
 		if err == nil {
-			db.Close()
+			_ = db.Close()
 			return nil
 		}
 		logger.Error(err, "connection failed")

server/initialize.go

@@ -312,7 +312,7 @@ func Init(ctx context.Context, db *sqlx.DB, socket string) error {
 		}
 		time.Sleep(1 * time.Second)
 	}
-	defer db.Close()
+	defer func() { _ = db.Close() }()
 
 	if err := dropLocalRootUser(ctx, db); err != nil {
 		return err

server/mysqld_health.go

@@ -11,13 +11,12 @@ import (
 
 // Health returns the health check result of own MySQL
 func (a *Agent) MySQLDHealth(w http.ResponseWriter, r *http.Request) {
-	rows, err := a.db.QueryxContext(r.Context(), `SELECT VERSION()`)
-	if err != nil {
+	var version string
+	if err := a.db.GetContext(r.Context(), &version, `SELECT VERSION()`); err != nil {
 		a.logger.Info("health check failed")
 		http.Error(w, "failed to execute a query", http.StatusServiceUnavailable)
 		return
 	}
-	rows.Close()
 }
 
 func (a *Agent) MySQLDReady(w http.ResponseWriter, r *http.Request) {

server/mysqld_health_test.go

@@ -102,7 +102,7 @@ var _ = Describe("health", func() {
 		Expect(err).NotTo(HaveOccurred())
 		_, err = donorDB.Exec("CREATE TABLE foo.bar (i INT PRIMARY KEY) ENGINE=InnoDB")
 		Expect(err).NotTo(HaveOccurred())
-		items := []interface{}{100, 299, 993, 9292}
+		items := []any{100, 299, 993, 9292}
 		_, err = donorDB.Exec("INSERT INTO foo.bar (i) VALUES (?), (?), (?), (?)", items...)
 		Expect(err).NotTo(HaveOccurred())
 
@@ -119,7 +119,7 @@ var _ = Describe("health", func() {
 		Expect(err).NotTo(HaveOccurred())
 
 		By("checking readiness")
-		Eventually(func() interface{} {
+		Eventually(func() any {
 			return getReady(agent)
 		}).Should(HaveHTTPStatus(http.StatusOK))
 
@@ -131,14 +131,14 @@ var _ = Describe("health", func() {
 		time.Sleep(200 * time.Millisecond)
 		_, err = donorDB.Exec("ALTER TABLE foo.bar ADD COLUMN hoge TEXT")
 		Expect(err).NotTo(HaveOccurred())
-		Eventually(func() interface{} {
+		Eventually(func() any {
 			return getReady(agent)
 		}).Should(HaveHTTPStatus(http.StatusServiceUnavailable))
 
 		By("unlocking replica")
 		_, err = replicaDB.Exec(`UNLOCK INSTANCE`)
 		Expect(err).NotTo(HaveOccurred())
-		Eventually(func() interface{} {
+		Eventually(func() any {
 			return getReady(agent)
 		}).Should(HaveHTTPStatus(http.StatusOK))
 	})
@@ -196,10 +196,10 @@ var _ = Describe("health", func() {
 		// The uptime observed by the agent is about 15s smaller than the process uptime reported by kernel
 		// The test flow takes about 35s from the process start to this point.
 		// We set Consistently timeout to 60(transactionQueueingWait) - (35 - 15) - 5(margin) = 35
-		Consistently(func() interface{} {
+		Consistently(func() any {
 			return getReady(agent)
 		}).WithPolling(time.Second).WithTimeout(time.Second * 35).ShouldNot(HaveHTTPStatus(http.StatusOK))
-		Eventually(func() interface{} {
+		Eventually(func() any {
 			return getReady(agent)
 		}).WithPolling(time.Second).WithTimeout(time.Second * 10).Should(HaveHTTPStatus(http.StatusOK))
 	})

server/suite_test.go

@@ -1,7 +1,7 @@
 package server
 
 import (
-	"log" // restrictpkg:ignore to suppress mysql client logs.
+	"log"
 	"os"
 	"testing"
 	"time"