Chore: Fix linting issues caught by ruleguard (#28799)

* Chore: Fix linting issues caught by ruleguard

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

* Improve error check

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

pkg/bus/bus.go

@@ -3,6 +3,7 @@ package bus
 import (
 	"context"
 	"errors"
+	"fmt"
 	"reflect"
 )
 
@@ -140,9 +141,13 @@ func (b *InProcBus) Publish(msg Msg) error {
 
 	for _, listenerHandler := range listeners {
 		ret := reflect.ValueOf(listenerHandler).Call(params)
-		err := ret[0].Interface()
-		if err != nil {
-			return err.(error)
+		e := ret[0].Interface()
+		if e != nil {
+			err, ok := e.(error)
+			if ok {
+				return err
+			}
+			return fmt.Errorf("expected listener to return an error, got '%T'", e)
 		}
 	}
 

pkg/middleware/auth_proxy.go

@@ -15,11 +15,11 @@ var header = setting.AuthProxyHeaderName
 func logUserIn(auth *authproxy.AuthProxy, username string, logger log.Logger, ignoreCache bool) (int64, *authproxy.Error) {
 	logger.Debug("Trying to log user in", "username", username, "ignoreCache", ignoreCache)
 	// Try to log in user via various providers
-	id, err := auth.Login(logger, ignoreCache)
-	if err != nil {
-		logger.Error("Failed to login", "username", username, "message", err.Error(), "error", err.DetailsError,
+	id, e := auth.Login(logger, ignoreCache)
+	if e != nil {
+		logger.Error("Failed to login", "username", username, "message", e.Error(), "error", e.DetailsError,
 			"ignoreCache", ignoreCache)
-		return 0, err
+		return 0, e
 	}
 	return id, nil
 }
@@ -55,16 +55,16 @@ func initContextWithAuthProxy(store *remotecache.RemoteCache, ctx *models.ReqCon
 		return true
 	}
 
-	id, err := logUserIn(auth, username, logger, false)
-	if err != nil {
-		ctx.Handle(407, err.Error(), err.DetailsError)
+	id, e := logUserIn(auth, username, logger, false)
+	if e != nil {
+		ctx.Handle(407, e.Error(), e.DetailsError)
 		return true
 	}
 
 	logger.Debug("Got user ID, getting full user info", "userID", id)
 
-	user, err := auth.GetSignedUser(id)
-	if err != nil {
+	user, e := auth.GetSignedUser(id)
+	if e != nil {
 		// The reason we couldn't find the user corresponding to the ID might be that the ID was found from a stale
 		// cache entry. For example, if a user is deleted via the API, corresponding cache entries aren't invalidated
 		// because cache keys are computed from request header values and not just the user ID. Meaning that
@@ -76,15 +76,15 @@ func initContextWithAuthProxy(store *remotecache.RemoteCache, ctx *models.ReqCon
 				logger.Error("Got unexpected error when removing user from auth cache", "error", err)
 			}
 		}
-		id, err = logUserIn(auth, username, logger, true)
-		if err != nil {
-			ctx.Handle(407, err.Error(), err.DetailsError)
+		id, e = logUserIn(auth, username, logger, true)
+		if e != nil {
+			ctx.Handle(407, e.Error(), e.DetailsError)
 			return true
 		}
 
-		user, err = auth.GetSignedUser(id)
-		if err != nil {
-			ctx.Handle(407, err.Error(), err.DetailsError)
+		user, e = auth.GetSignedUser(id)
+		if e != nil {
+			ctx.Handle(407, e.Error(), e.DetailsError)
 			return true
 		}
 	}
@@ -96,14 +96,14 @@ func initContextWithAuthProxy(store *remotecache.RemoteCache, ctx *models.ReqCon
 	ctx.IsSignedIn = true
 
 	// Remember user data in cache
-	if err := auth.Remember(id); err != nil {
+	if e := auth.Remember(id); e != nil {
 		logger.Error(
 			"Failed to store user in cache",
 			"username", username,
-			"message", err.Error(),
-			"error", err.DetailsError,
+			"message", e.Error(),
+			"error", e.DetailsError,
 		)
-		ctx.Handle(500, err.Error(), err.DetailsError)
+		ctx.Handle(500, e.Error(), e.DetailsError)
 		return true
 	}
 

pkg/middleware/auth_proxy/auth_proxy.go

@@ -6,6 +6,7 @@ import (
 	"hash/fnv"
 	"net"
 	"net/mail"
+	"path"
 	"reflect"
 	"strings"
 	"time"
@@ -179,12 +180,12 @@ func (auth *AuthProxy) Login(logger log.Logger, ignoreCache bool) (int64, *Error
 	}
 
 	if isLDAPEnabled() {
-		id, err := auth.LoginViaLDAP()
-		if err != nil {
-			if err == ldap.ErrInvalidCredentials {
+		id, e := auth.LoginViaLDAP()
+		if e != nil {
+			if e == ldap.ErrInvalidCredentials {
 				return 0, newError("proxy authentication required", ldap.ErrInvalidCredentials)
 			}
-			return 0, newError("failed to get the user", err)
+			return 0, newError("failed to get the user", e)
 		}
 
 		return id, nil
@@ -347,7 +348,7 @@ func (auth *AuthProxy) Remember(id int64) *Error {
 func coerceProxyAddress(proxyAddr string) (*net.IPNet, error) {
 	proxyAddr = strings.TrimSpace(proxyAddr)
 	if !strings.Contains(proxyAddr, "/") {
-		proxyAddr = strings.Join([]string{proxyAddr, "32"}, "/")
+		proxyAddr = path.Join(proxyAddr, "32")
 	}
 
 	_, network, err := net.ParseCIDR(proxyAddr)

pkg/tsdb/mssql/macros.go

@@ -90,7 +90,7 @@ func (m *msSqlMacroEngine) evaluateMacro(name string, args []string) (string, er
 	case "__timeGroupAlias":
 		tg, err := m.evaluateMacro("__timeGroup", args)
 		if err == nil {
-			return tg + " AS [time]", err
+			return tg + " AS [time]", nil
 		}
 		return "", err
 	case "__unixEpochFilter":
@@ -125,7 +125,7 @@ func (m *msSqlMacroEngine) evaluateMacro(name string, args []string) (string, er
 	case "__unixEpochGroupAlias":
 		tg, err := m.evaluateMacro("__unixEpochGroup", args)
 		if err == nil {
-			return tg + " AS [time]", err
+			return tg + " AS [time]", nil
 		}
 		return "", err
 	default:

pkg/tsdb/mysql/macros.go

@@ -96,7 +96,7 @@ func (m *mySqlMacroEngine) evaluateMacro(name string, args []string) (string, er
 	case "__timeGroupAlias":
 		tg, err := m.evaluateMacro("__timeGroup", args)
 		if err == nil {
-			return tg + " AS \"time\"", err
+			return tg + " AS \"time\"", nil
 		}
 		return "", err
 	case "__unixEpochFilter":
@@ -131,7 +131,7 @@ func (m *mySqlMacroEngine) evaluateMacro(name string, args []string) (string, er
 	case "__unixEpochGroupAlias":
 		tg, err := m.evaluateMacro("__unixEpochGroup", args)
 		if err == nil {
-			return tg + " AS \"time\"", err
+			return tg + " AS \"time\"", nil
 		}
 		return "", err
 	default:

pkg/tsdb/postgres/macros.go

@@ -120,7 +120,7 @@ func (m *postgresMacroEngine) evaluateMacro(name string, args []string) (string,
 	case "__timeGroupAlias":
 		tg, err := m.evaluateMacro("__timeGroup", args)
 		if err == nil {
-			return tg + " AS \"time\"", err
+			return tg + " AS \"time\"", nil
 		}
 		return "", err
 	case "__unixEpochFilter":
@@ -155,7 +155,7 @@ func (m *postgresMacroEngine) evaluateMacro(name string, args []string) (string,
 	case "__unixEpochGroupAlias":
 		tg, err := m.evaluateMacro("__unixEpochGroup", args)
 		if err == nil {
-			return tg + " AS \"time\"", err
+			return tg + " AS \"time\"", nil
 		}
 		return "", err
 	default: