TUN-8855: fix lint issues

## Summary

Fix lint issues necessary for a subsequent PR. This is only separate to allow a better code review of the actual changes.

Closes TUN-8855

cmd/cloudflared/macos_service.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"os"
 
+	homedir "github.com/mitchellh/go-homedir"
 	"github.com/pkg/errors"
 	"github.com/urfave/cli/v2"
 
@@ -17,7 +18,7 @@ const (
 	launchdIdentifier = "com.cloudflare.cloudflared"
 )
 
-func runApp(app *cli.App, graceShutdownC chan struct{}) {
+func runApp(app *cli.App, _ chan struct{}) {
 	app.Commands = append(app.Commands, &cli.Command{
 		Name:  "service",
 		Usage: "Manages the cloudflared launch agent",
@@ -207,3 +208,15 @@ func uninstallLaunchd(c *cli.Context) error {
 	}
 	return err
 }
+
+func userHomeDir() (string, error) {
+	// This returns the home dir of the executing user using OS-specific method
+	// for discovering the home dir. It's not recommended to call this function
+	// when the user has root permission as $HOME depends on what options the user
+	// use with sudo.
+	homeDir, err := homedir.Dir()
+	if err != nil {
+		return "", errors.Wrap(err, "Cannot determine home directory for the user")
+	}
+	return homeDir, nil
+}

cmd/cloudflared/main.go

@@ -2,14 +2,11 @@ package main
 
 import (
 	"fmt"
-	"math/rand"
 	"os"
 	"strings"
 	"time"
 
 	"github.com/getsentry/sentry-go"
-	homedir "github.com/mitchellh/go-homedir"
-	"github.com/pkg/errors"
 	"github.com/urfave/cli/v2"
 	"go.uber.org/automaxprocs/maxprocs"
 
@@ -52,10 +49,8 @@ var (
 func main() {
 	// FIXME: TUN-8148: Disable QUIC_GO ECN due to bugs in proper detection if supported
 	os.Setenv("QUIC_GO_DISABLE_ECN", "1")
-
-	rand.Seed(time.Now().UnixNano())
 	metrics.RegisterBuildInfo(BuildType, BuildTime, Version)
-	maxprocs.Set()
+	_, _ = maxprocs.Set()
 	bInfo := cliutil.GetBuildInfo(BuildType, Version)
 
 	// Graceful shutdown channel used by the app. When closed, app must terminate gracefully.
@@ -184,18 +179,6 @@ func action(graceShutdownC chan struct{}) cli.ActionFunc {
 	})
 }
 
-func userHomeDir() (string, error) {
-	// This returns the home dir of the executing user using OS-specific method
-	// for discovering the home dir. It's not recommended to call this function
-	// when the user has root permission as $HOME depends on what options the user
-	// use with sudo.
-	homeDir, err := homedir.Dir()
-	if err != nil {
-		return "", errors.Wrap(err, "Cannot determine home directory for the user")
-	}
-	return homeDir, nil
-}
-
 // In order to keep the amount of noise sent to Sentry low, typical network errors can be filtered out here by a substring match.
 func captureError(err error) {
 	errorMessage := err.Error()

cmd/cloudflared/tunnel/cmd.go

@@ -126,7 +126,7 @@ var (
 	routeFailMsg = fmt.Sprintf("failed to provision routing, please create it manually via Cloudflare dashboard or UI; "+
 		"most likely you already have a conflicting record there. You can also rerun this command with --%s to overwrite "+
 		"any existing DNS records for this hostname.", overwriteDNSFlag)
-	deprecatedClassicTunnelErr = fmt.Errorf("Classic tunnels have been deprecated, please use Named Tunnels. (https://developers.cloudflare.com/cloudflare-one/connections/connect-apps/install-and-setup/tunnel-guide/)")
+	errDeprecatedClassicTunnel = fmt.Errorf("Classic tunnels have been deprecated, please use Named Tunnels. (https://developers.cloudflare.com/cloudflare-one/connections/connect-apps/install-and-setup/tunnel-guide/)")
 	// TODO: TUN-8756 the list below denotes the flags that do not possess any kind of sensitive information
 	// however this approach is not maintainble in the long-term.
 	nonSecretFlagsList = []string{
@@ -326,7 +326,7 @@ func TunnelCommand(c *cli.Context) error {
 
 	// Classic tunnel usage is no longer supported
 	if c.String("hostname") != "" {
-		return deprecatedClassicTunnelErr
+		return errDeprecatedClassicTunnel
 	}
 
 	if c.IsSet("proxy-dns") {
@@ -615,8 +615,10 @@ func waitToShutdown(wg *sync.WaitGroup,
 		log.Debug().Msg("Graceful shutdown signalled")
 		if gracePeriod > 0 {
 			// wait for either grace period or service termination
+			ticker := time.NewTicker(gracePeriod)
+			defer ticker.Stop()
 			select {
-			case <-time.Tick(gracePeriod):
+			case <-ticker.C:
 			case <-errC:
 			}
 		}
@@ -644,7 +646,7 @@ func waitToShutdown(wg *sync.WaitGroup,
 
 func notifySystemd(waitForSignal *signal.Signal) {
 	<-waitForSignal.Wait()
-	daemon.SdNotify(false, "READY=1")
+	_, _ = daemon.SdNotify(false, "READY=1")
 }
 
 func writePidFile(waitForSignal *signal.Signal, pidPathname string, log *zerolog.Logger) {

cmd/cloudflared/tunnel/configuration.go

@@ -36,24 +36,11 @@ const (
 )
 
 var (
-	developerPortal = "https://developers.cloudflare.com/cloudflare-one/connections/connect-apps/install-and-setup"
-	serviceUrl      = developerPortal + "/tunnel-guide/local/as-a-service/"
-	argumentsUrl    = developerPortal + "/tunnel-guide/local/local-management/arguments/"
-
 	secretFlags = [2]*altsrc.StringFlag{credentialsContentsFlag, tunnelTokenFlag}
 
 	configFlags = []string{"autoupdate-freq", "no-autoupdate", "retries", "protocol", "loglevel", "transport-loglevel", "origincert", "metrics", "metrics-update-freq", "edge-ip-version", "edge-bind-address"}
 )
 
-func generateRandomClientID(log *zerolog.Logger) (string, error) {
-	u, err := uuid.NewRandom()
-	if err != nil {
-		log.Error().Msgf("couldn't create UUID for client ID %s", err)
-		return "", err
-	}
-	return u.String(), nil
-}
-
 func logClientOptions(c *cli.Context, log *zerolog.Logger) {
 	flags := make(map[string]interface{})
 	for _, flag := range c.FlagNames() {
@@ -233,13 +220,13 @@ func prepareTunnelConfig(
 		Observer:        observer,
 		ReportedVersion: info.Version(),
 		// Note TUN-3758 , we use Int because UInt is not supported with altsrc
-		Retries:                             uint(c.Int("retries")),
+		Retries:                             uint(c.Int("retries")), // nolint: gosec
 		RunFromTerminal:                     isRunningFromTerminal(),
 		NamedTunnel:                         namedTunnel,
 		ProtocolSelector:                    protocolSelector,
 		EdgeTLSConfigs:                      edgeTLSConfigs,
 		FeatureSelector:                     featureSelector,
-		MaxEdgeAddrRetries:                  uint8(c.Int("max-edge-addr-retries")),
+		MaxEdgeAddrRetries:                  uint8(c.Int("max-edge-addr-retries")), // nolint: gosec
 		RPCTimeout:                          c.Duration(rpcTimeout),
 		WriteStreamTimeout:                  c.Duration(writeStreamTimeout),
 		DisableQUICPathMTUDiscovery:         c.Bool(quicDisablePathMTUDiscovery),

cmd/cloudflared/tunnel/subcommands.go

@@ -441,7 +441,7 @@ func fmtConnections(connections []cfapi.Connection, showRecentlyDisconnected boo
 	sort.Strings(sortedColos)
 
 	// Map each colo to its frequency, combine into output string.
-	var output []string
+	output := make([]string, 0, len(sortedColos))
 	for _, coloName := range sortedColos {
 		output = append(output, fmt.Sprintf("%dx%s", numConnsPerColo[coloName], coloName))
 	}
@@ -467,10 +467,15 @@ func readyCommand(c *cli.Context) error {
 	}
 
 	requestURL := fmt.Sprintf("http://%s/ready", metricsOpts)
-	res, err := http.Get(requestURL)
+	req, err := http.NewRequest(http.MethodGet, requestURL, nil)
 	if err != nil {
 		return err
 	}
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
 	if res.StatusCode != 200 {
 		body, err := io.ReadAll(res.Body)
 		if err != nil {

connection/protocol.go

@@ -14,7 +14,7 @@ import (
 const (
 	AvailableProtocolFlagMessage = "Available protocols: 'auto' - automatically chooses the best protocol over time (the default; and also the recommended one); 'quic' - based on QUIC, relying on UDP egress to Cloudflare edge; 'http2' - using Go's HTTP2 library, relying on TCP egress to Cloudflare edge"
 	// edgeH2muxTLSServerName is the server name to establish h2mux connection with edge (unused, but kept for legacy reference).
-	edgeH2muxTLSServerName = "cftunnel.com"
+	_ = "cftunnel.com"
 	// edgeH2TLSServerName is the server name to establish http2 connection with edge
 	edgeH2TLSServerName = "h2.cftunnel.com"
 	// edgeQUICServerName is the server name to establish quic connection with edge.
@@ -24,11 +24,9 @@ const (
 	ResolveTTL = time.Hour
 )
 
-var (
 // ProtocolList represents a list of supported protocols for communication with the edge
 // in order of precedence for remote percentage fetcher.
-	ProtocolList = []Protocol{QUIC, HTTP2}
+var ProtocolList = []Protocol{QUIC, HTTP2}
-)
 
 type Protocol int64
 
@@ -58,7 +56,7 @@ func (p Protocol) String() string {
 	case QUIC:
 		return "quic"
 	default:
-		return fmt.Sprintf("unknown protocol")
+		return "unknown protocol"
 	}
 }
 
@@ -246,11 +244,11 @@ func NewProtocolSelector(
 		return newRemoteProtocolSelector(fetchedProtocol, ProtocolList, threshold, protocolFetcher, resolveTTL, log), nil
 	}
 
-	return nil, fmt.Errorf("Unknown protocol %s, %s", protocolFlag, AvailableProtocolFlagMessage)
+	return nil, fmt.Errorf("unknown protocol %s, %s", protocolFlag, AvailableProtocolFlagMessage)
 }
 
 func switchThreshold(accountTag string) int32 {
 	h := fnv.New32a()
 	_, _ = h.Write([]byte(accountTag))
-	return int32(h.Sum32() % 100)
+	return int32(h.Sum32() % 100) // nolint: gosec
 }

connection/quic_connection.go

@@ -103,9 +103,15 @@ func (q *quicConnection) Serve(ctx context.Context) error {
 		// amount of the grace period, allowing requests to finish before we cancel the context, which will
 		// make cloudflared exit.
 		if err := q.serveControlStream(ctx, controlStream); err == nil {
+			if q.gracePeriod > 0 {
+				// In Go1.23 this can be removed and replaced with time.Ticker
+				// see https://pkg.go.dev/time#Tick
+				ticker := time.NewTicker(q.gracePeriod)
+				defer ticker.Stop()
 				select {
 				case <-ctx.Done():
-			case <-time.Tick(q.gracePeriod):
+				case <-ticker.C:
+				}
 			}
 		}
 		cancel()

features/features.go

@@ -11,15 +11,13 @@ const (
 	FeatureDatagramV3        = "support_datagram_v3"
 )
 
-var (
+var defaultFeatures = []string{
-	defaultFeatures = []string{
 	FeatureAllowRemoteConfig,
 	FeatureSerializedHeaders,
 	FeatureDatagramV2,
 	FeatureQUICSupportEOF,
 	FeatureManagementLogs,
 }
-)
 
 // Features set by user provided flags
 type staticFeatures struct {
@@ -47,7 +45,6 @@ const (
 
 // Remove any duplicates from the slice
 func Dedup(slice []string) []string {
-
 	// Convert the slice into a set
 	set := make(map[string]bool, 0)
 	for _, str := range slice {