update linter checks with newer linters

.github/workflows/go.yml

@@ -30,6 +30,6 @@ jobs:
         env:
           GO111MODULE: on
         run: |
-          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.27.0
+          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.46.2
           $(go env GOPATH)/bin/golangci-lint run --timeout=5m --config ./.golangci.yml
           go test -v -race ./...

.golangci.yml

@@ -12,11 +12,21 @@ linters:
     - goimports
     - misspell
     - govet
-    - golint
+    - revive
     - ineffassign
     - gosimple
     - deadcode
     - structcheck
+    - gomodguard
+    - gofmt
+    - unused
+    - structcheck
+    - unconvert
+    - varcheck
+    - gocritic
+    - gofumpt
+    - tenv
+    - durationcheck
 
 issues:
   exclude-use-default: false

cache-utils.go

@@ -44,7 +44,6 @@ func NewRecorder() *ResponseRecorder {
 		pw:         pw,
 		pr:         pr,
 	}
-
 }
 
 // Header needed for implementing "net/http".ResponseWriter
@@ -171,6 +170,7 @@ func (t *multiWriter) Write(p []byte) (n int, err error) {
 	}
 	return len(p), nil
 }
+
 func cacheMultiWriter(w1 io.Writer, w2 *io.PipeWriter) io.Writer {
 	return &multiWriter{backendWriter: w1, cacheWriter: w2}
 }

cache.go

@@ -79,11 +79,12 @@ type S3CacheClient struct {
 
 func (c *S3CacheClient) setOffline() {
 	atomic.StoreInt32(&c.up, 0)
-
 }
+
 func (c *S3CacheClient) isOnline() bool {
 	return atomic.LoadInt32(&c.up) == 1
 }
+
 func (c *S3CacheClient) isCacheable(method string) bool {
 	for _, m := range c.methods {
 		if method == m {
@@ -102,7 +103,7 @@ func (c *S3CacheClient) healthCheck() {
 				logMsg(logMessage{Endpoint: c.endpoint, Error: err})
 			}
 			c.setOffline()
-			time.Sleep(time.Duration(c.healthCheckDuration) * time.Second)
+			time.Sleep(c.healthCheckDuration)
 			continue
 		}
 
@@ -121,7 +122,7 @@ func (c *S3CacheClient) healthCheck() {
 			}
 
 		}
-		time.Sleep(time.Duration(c.healthCheckDuration) * time.Second)
+		time.Sleep(c.healthCheckDuration)
 	}
 }
 
@@ -213,18 +214,21 @@ func parseCacheControlHeaders(header http.Header) *cacheControl {
 	}
 	return &c
 }
+
 func (c *cacheControl) revalidate() bool {
 	if c == nil {
 		return true
 	}
 	return c.noCache || c.mustRevalidate
 }
+
 func (c *cacheControl) neverCache() bool {
 	if c == nil {
 		return false
 	}
 	return c.private || c.noStore
 }
+
 func (c *cacheControl) fresh(modTime time.Time) bool {
 	if c == nil {
 		return false
@@ -328,7 +332,7 @@ func getCacheResponseHeaders(oi minio.ObjectInfo) (ch cacheHeader) {
 	return ch
 }
 
-//Expires returns expires header from cached response
+// Expires returns expires header from cached response
 func (c cacheHeader) Expires() time.Time {
 	if v := c.Header.Get("Expires"); v != "" {
 		if t, e := time.Parse(http.TimeFormat, v); e == nil {
@@ -338,12 +342,12 @@ func (c cacheHeader) Expires() time.Time {
 	return time.Time{}
 }
 
-//ETag returns ETag from cached response
+// ETag returns ETag from cached response
 func (c cacheHeader) ETag() string {
 	return c.Header.Get("Etag")
 }
 
-//LastModified returns last modified header from cached response
+// LastModified returns last modified header from cached response
 func (c cacheHeader) LastModified() time.Time {
 	if v := c.Header.Get("Last-Modified"); v != "" {
 		if t, e := time.Parse(http.TimeFormat, v); e == nil {
@@ -505,6 +509,7 @@ func (h *HTTPRangeSpec) String(resourceSize int64) string {
 	}
 	return fmt.Sprintf("%d-%d", off, off+length-1)
 }
+
 func (c cacheHeader) Range() (rs *HTTPRangeSpec) {
 	if rangeHeader, ok := c.Header["Range"]; ok {
 		if len(rangeHeader) != 0 {
@@ -527,6 +532,7 @@ func getPutMetadata(h http.Header) map[string]string {
 	}
 	return metadata
 }
+
 func isFresh(cacheCC, reqCC *cacheControl, lastModified time.Time) bool {
 	if cacheCC == nil && reqCC == nil {
 		return false
@@ -753,14 +759,16 @@ func newCacheConfig() *cacheConfig {
 			console.Fatalln(fmt.Errorf("Unable to parse SIDEKICK_CACHE_HEALTH_DURATION %s should be an integer", durationStr))
 		}
 	}
-	return &cacheConfig{endpoint: cURL,
+	return &cacheConfig{
+		endpoint:  cURL,
 		accessKey: accessKey,
 		secretKey: secretKey,
 		bucket:    bucket,
 		minSize:   minSize,
 		duration:  time.Duration(duration) * time.Second,
 	}
 }
+
 func newCacheClient(ctx *cli.Context, cfg *cacheConfig) *S3CacheClient {
 	if cfg == nil {
 		return nil
@@ -844,14 +852,14 @@ func newCacheClient(ctx *cli.Context, cfg *cacheConfig) *S3CacheClient {
 	return s3Clnt
 }
 
-func sortURLParams(URL *url.URL) {
-	params := URL.Query()
+func sortURLParams(u *url.URL) {
+	params := u.Query()
 	for _, param := range params {
 		sort.Slice(param, func(i, j int) bool {
 			return param[i] < param[j]
 		})
 	}
-	URL.RawQuery = params.Encode()
+	u.RawQuery = params.Encode()
 }
 
 func generateKey(u *url.URL, host string) string {

go.mod

@@ -51,5 +51,5 @@ require (
 	golang.org/x/text v0.3.7 // indirect
 	google.golang.org/protobuf v1.27.1 // indirect
 	gopkg.in/ini.v1 v1.63.2 // indirect
-	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
+	gopkg.in/yaml.v3 v3.0.0 // indirect
 )

go.sum

@@ -642,8 +642,8 @@ gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b h1:h8qDotaEPuJATrMmW04NCwg7v22aHH28wwpauUhK9Oo=
-gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0 h1:hjy8E9ON/egN1tAYqKb61G10WtihqetD4sz2H+8nIeA=
+gopkg.in/yaml.v3 v3.0.0/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190106161140-3f1c8253044a/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190418001031-e561f6794a2a/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=

http-tracer.go

@@ -61,6 +61,7 @@ func (r *recordRequest) Read(p []byte) (n int, err error) {
 	}
 	return n, err
 }
+
 func (r *recordRequest) Size() int {
 	sz := r.bytesRead
 	for k, v := range r.headers {
@@ -171,6 +172,7 @@ func (r *recordRequest) Data() []byte {
 	// ... otherwise we return <BODY> placeholder
 	return BodyPlaceHolder
 }
+
 func httpInternalTrace(req *http.Request, resp *http.Response, reqTime, respTime time.Time, backend *Backend) {
 	ti := InternalTrace(req, resp, reqTime, respTime)
 	doTrace(ti, backend)
@@ -370,7 +372,7 @@ type shortTraceMsg struct {
 }
 
 func (s shortTraceMsg) String() string {
-	var b = &strings.Builder{}
+	b := &strings.Builder{}
 	fmt.Fprintf(b, " %5s: ", TraceMsgType)
 	fmt.Fprintf(b, "%s ", s.Time.Format(timeFormat))
 	statusStr := console.Colorize("RespStatus", fmt.Sprintf("%d %s", s.StatusCode, s.StatusMsg))
@@ -418,9 +420,10 @@ func shortTrace(t TraceInfo) shortTraceMsg {
 	s.Method = t.ReqInfo.Method
 	return s
 }
+
 func (trc TraceInfo) String() string {
 	var nodeNameStr string
-	var b = &strings.Builder{}
+	b := &strings.Builder{}
 
 	if trc.NodeName != "" {
 		nodeNameStr = fmt.Sprintf("%s: %s ", console.Colorize("TraceMsgType", DebugMsgType), trc.NodeName)
@@ -446,7 +449,7 @@ func (trc TraceInfo) String() string {
 			fmt.Sprintf("%s: ", k))+console.Colorize("HeaderValue", fmt.Sprintf("%s\n", strings.Join(v, ""))))
 	}
 
-	fmt.Fprintf(b, "%s%s", nodeNameStr, console.Colorize("Body", fmt.Sprintf("%s\n", string(ri.Body))))
+	fmt.Fprintf(b, "%s%s", nodeNameStr, console.Colorize("Body", fmt.Sprintf("%s\n", ri.Body)))
 	fmt.Fprintf(b, "%s%s", nodeNameStr, console.Colorize("Response", "[RESPONSE] "))
 	fmt.Fprintf(b, "[%s] ", rs.Time.Format(timeFormat))
 	fmt.Fprint(b, console.Colorize("Stat", fmt.Sprintf("[ Duration %2s  ↑ %s  ↓ %s ]\n", trc.CallStats.Latency.Round(time.Microsecond), humanize.IBytes(uint64(trc.CallStats.Rx)), humanize.IBytes(uint64(trc.CallStats.Tx)))))
@@ -461,7 +464,7 @@ func (trc TraceInfo) String() string {
 		fmt.Fprintf(b, "%s%s", nodeNameStr, console.Colorize("RespHeaderKey",
 			fmt.Sprintf("%s: ", k))+console.Colorize("HeaderValue", fmt.Sprintf("%s\n", strings.Join(v, ""))))
 	}
-	fmt.Fprintf(b, "%s%s\n", nodeNameStr, console.Colorize("Body", string(rs.Body)))
+	fmt.Fprintf(b, "%s%s\n", nodeNameStr, console.Colorize("Body", rs.Body))
 	fmt.Fprint(b, nodeNameStr)
 	return b.String()
 }

main.go

@@ -301,7 +301,7 @@ func (b *Backend) updateDowntime(downtime time.Duration) {
 	b.Stats.Lock()
 	defer b.Stats.Unlock()
 	b.Stats.LastDowntime = downtime
-	b.Stats.CumDowntime = b.Stats.CumDowntime + downtime
+	b.Stats.CumDowntime += downtime
 }
 
 // updateCallStats updates the cumulative stats for each call to backend
@@ -424,7 +424,7 @@ func getCertPool(cacert string) *x509.CertPool {
 	if err != nil {
 		console.Fatalln(fmt.Errorf("unable to load CA certificate: %s", err))
 	}
-	ok := pool.AppendCertsFromPEM([]byte(caPEM))
+	ok := pool.AppendCertsFromPEM(caPEM)
 	if !ok {
 		console.Fatalln(fmt.Errorf("unable to load CA certificate: %s is not valid certificate", cacert))
 	}
@@ -447,7 +447,7 @@ func getCertKeyPair(cert, key string) []tls.Certificate {
 	if err != nil {
 		console.Fatalln(fmt.Errorf("unable to load key: %s", err))
 	}
-	keyPair, err := tls.X509KeyPair([]byte(certPEM), []byte(keyPEM))
+	keyPair, err := tls.X509KeyPair(certPEM, keyPEM)
 	if err != nil {
 		console.Fatalln(fmt.Errorf("%s", err))
 	}
@@ -631,7 +631,7 @@ func configureSite(ctx *cli.Context, siteNum int, siteStrs []string, healthCheck
 			Transport: transport,
 		}
 
-		stats := BackendStats{MinLatency: time.Duration(24 * time.Hour), MaxLatency: time.Duration(0)}
+		stats := BackendStats{MinLatency: 24 * time.Hour, MaxLatency: 0}
 		backend := &Backend{siteNum, endpoint, proxy, &http.Client{
 			Transport: proxy.Transport,
 		}, 0, healthCheckPath, healthCheckPort, healthCheckDuration, &stats, newCacheClient(ctx, cacheCfg)}

main_linux.go

@@ -1,3 +1,4 @@
+//go:build linux
 // +build linux
 
 // Copyright (c) 2021 MinIO, Inc.
@@ -45,7 +46,6 @@ func setTCPParameters(network, address string, c syscall.RawConn) error {
 		// Enable TCP quick ACK, John Nagle says
 		// "Set TCP_QUICKACK. If you find a case where that makes things worse, let me know."
 		_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, unix.TCP_QUICKACK, 1)
-
 	})
 	return nil
 }

main_others.go

@@ -1,3 +1,4 @@
+//go:build !linux
 // +build !linux
 
 // Copyright (c) 2021 MinIO, Inc.

main_test.go

@@ -54,7 +54,6 @@ func TestGetHealthCheckURL_Valid(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			// ----- call -----------------------------------------------------
 			healthCheckURL, err := getHealthCheckURL(tc.endpoint, tc.healthCheckPath, tc.healthCheckPort)
-
 			// ----- verify ---------------------------------------------------
 			if err != nil {
 				t.Errorf("Expected no error, got %q", err)

metrics.go

@@ -50,7 +50,6 @@ func (c *sidekickCollector) Describe(ch chan<- *prometheus.Desc) {
 
 // Collect is called by the Prometheus registry when collecting metrics.
 func (c *sidekickCollector) Collect(ch chan<- prometheus.Metric) {
-
 	for _, c := range globalConnStats {
 		if c == nil {
 			continue
@@ -94,7 +93,6 @@ func (c *sidekickCollector) Collect(ch chan<- prometheus.Metric) {
 			c.endpoint,
 		)
 	}
-
 }
 
 func metricsHandler() (http.Handler, error) {
@@ -117,7 +115,6 @@ func metricsHandler() (http.Handler, error) {
 				ErrorHandling: promhttp.ContinueOnError,
 			}),
 	), nil
-
 }
 
 // ConnStats - statistics on backend
@@ -129,7 +126,6 @@ type ConnStats struct {
 	totalFailedCalls atomic.Uint64
 	minLatency       atomic.Duration
 	maxLatency       atomic.Duration
-	status           atomic.String
 }
 
 // Store current total input bytes
@@ -157,11 +153,6 @@ func (s *ConnStats) setTotalCallFailures(n int64) {
 	s.totalFailedCalls.Store(uint64(n))
 }
 
-// set backend status
-func (s *ConnStats) setStatus(st string) {
-	s.status.Store(st)
-}
-
 // set min latency
 func (s *ConnStats) setMinLatency(mn time.Duration) {
 	s.minLatency.Store(mn)