internal: Simplify code by using modern constructs

internal/filter/value.go

@@ -61,7 +61,7 @@ func ValueOf(obj any, field string) any {
 		}
 	}
 
-	for i := 0; i < value.NumField(); i++ {
+	for i := range value.NumField() {
 		fieldValue := value.Field(i)
 		fieldType := typ.Field(i)
 		yaml := fieldType.Tag.Get("yaml")

internal/linux/kernel.go

@@ -62,7 +62,7 @@ func Uname() (*Utsname, error) {
 func intArrayToString(arr any) string {
 	slice := reflect.ValueOf(arr)
 	s := ""
-	for i := 0; i < slice.Len(); i++ {
+	for i := range slice.Len() {
 		val := slice.Index(i)
 		valInt := int64(-1)
 

internal/server/apparmor/qemuimg_test.go

@@ -13,8 +13,8 @@ func TestHandleWriter(t *testing.T) {
 		status = append(status, percent)
 	})}
 
-	for i := 0; i < 101; i++ {
-		for j := 0; j < 100; j++ {
+	for i := range 101 {
+		for j := range 100 {
 			n, err := fmt.Fprintf(out, "\t    (%02d.%02d/100%s)\r", i, j, "%")
 			if err != nil {
 				t.Fatal(err, n)

internal/server/auth/driver_tls.go

@@ -242,15 +242,12 @@ func (t *TLS) GetInstanceAccess(ctx context.Context, projectName string, instanc
 		}
 
 		// Restricted
-		for _, proj := range certificateProjects {
-			if proj == projectName {
-				access = append(access, api.AccessEntry{
-					Identifier: fingerprint,
-					Role:       "operator",
-					Provider:   "tls",
-				})
-				break
-			}
+		if slices.Contains(certificateProjects, projectName) {
+			access = append(access, api.AccessEntry{
+				Identifier: fingerprint,
+				Role:       "operator",
+				Provider:   "tls",
+			})
 		}
 	}
 
@@ -270,15 +267,12 @@ func (t *TLS) GetInstanceAccess(ctx context.Context, projectName string, instanc
 		}
 
 		// Restricted
-		for _, proj := range certificateProjects {
-			if proj == projectName {
-				access = append(access, api.AccessEntry{
-					Identifier: fingerprint,
-					Role:       "view",
-					Provider:   "tls",
-				})
-				break
-			}
+		if slices.Contains(certificateProjects, projectName) {
+			access = append(access, api.AccessEntry{
+				Identifier: fingerprint,
+				Role:       "view",
+				Provider:   "tls",
+			})
 		}
 	}
 
@@ -304,15 +298,12 @@ func (t *TLS) GetProjectAccess(ctx context.Context, projectName string) (*api.Ac
 			})
 		}
 
-		for _, project := range certificateProjects {
-			if project == projectName {
-				access = append(access, api.AccessEntry{
-					Identifier: fingerprint,
-					Role:       "operator",
-					Provider:   "tls",
-				})
-				break
-			}
+		if slices.Contains(certificateProjects, projectName) {
+			access = append(access, api.AccessEntry{
+				Identifier: fingerprint,
+				Role:       "operator",
+				Provider:   "tls",
+			})
 		}
 	}
 
@@ -327,15 +318,12 @@ func (t *TLS) GetProjectAccess(ctx context.Context, projectName string) (*api.Ac
 			})
 		}
 
-		for _, project := range certificateProjects {
-			if project == projectName {
-				access = append(access, api.AccessEntry{
-					Identifier: fingerprint,
-					Role:       "view",
-					Provider:   "tls",
-				})
-				break
-			}
+		if slices.Contains(certificateProjects, projectName) {
+			access = append(access, api.AccessEntry{
+				Identifier: fingerprint,
+				Role:       "view",
+				Provider:   "tls",
+			})
 		}
 	}
 

internal/server/bgp/server.go

@@ -3,6 +3,7 @@ package bgp
 import (
 	"context"
 	"fmt"
+	"maps"
 	"net"
 	"strconv"
 	"sync"
@@ -113,9 +114,7 @@ func (s *Server) start(address string, asn uint32, routerID net.IP) error {
 
 	// Copy the path list
 	oldPaths := map[string]path{}
-	for pathUUID, path := range s.paths {
-		oldPaths[pathUUID] = path
-	}
+	maps.Copy(oldPaths, s.paths)
 
 	// Add existing paths.
 	s.paths = map[string]path{}
@@ -128,9 +127,7 @@ func (s *Server) start(address string, asn uint32, routerID net.IP) error {
 
 	// Copy the peer list.
 	oldPeers := map[string]peer{}
-	for peerUUID, peer := range s.peers {
-		oldPeers[peerUUID] = peer
-	}
+	maps.Copy(oldPeers, s.peers)
 
 	// Add existing peers.
 	s.peers = map[string]peer{}
@@ -158,9 +155,7 @@ func (s *Server) stop() error {
 
 	// Save the peer list.
 	oldPeers := map[string]peer{}
-	for peerUUID, peer := range s.peers {
-		oldPeers[peerUUID] = peer
-	}
+	maps.Copy(oldPeers, s.peers)
 
 	// Remove all the peers.
 	for _, peer := range s.peers {
@@ -332,9 +327,7 @@ func (s *Server) RemovePrefixByOwner(owner string) error {
 
 	// Make a copy of the paths dict to safely iterate (path removal mutates it).
 	paths := map[string]path{}
-	for pathUUID, path := range s.paths {
-		paths[pathUUID] = path
-	}
+	maps.Copy(paths, s.paths)
 
 	// Iterate through the paths and remove them from the server.
 	for pathUUID, path := range paths {

internal/server/certificate/cache.go

@@ -2,6 +2,7 @@ package certificate
 
 import (
 	"crypto/x509"
+	"maps"
 	"sync"
 )
 
@@ -50,9 +51,7 @@ func (c *Cache) GetCertificatesAndProjects() (map[Type]map[string]x509.Certifica
 	certificates := make(map[Type]map[string]x509.Certificate, len(c.certificates))
 	for t, m := range c.certificates {
 		certificates[t] = make(map[string]x509.Certificate, len(m))
-		for f, cert := range m {
-			certificates[t][f] = cert
-		}
+		maps.Copy(certificates[t], m)
 	}
 
 	projects := make(map[string][]string, len(c.projects))
@@ -73,9 +72,7 @@ func (c *Cache) GetCertificates() map[Type]map[string]x509.Certificate {
 	certificates := make(map[Type]map[string]x509.Certificate, len(c.certificates))
 	for t, m := range c.certificates {
 		certificates[t] = make(map[string]x509.Certificate, len(m))
-		for f, cert := range m {
-			certificates[t][f] = cert
-		}
+		maps.Copy(certificates[t], m)
 	}
 
 	return certificates

internal/server/cgroup/init.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"errors"
 	"io/fs"
+	"maps"
 	"os"
 	"path/filepath"
 	"strings"
@@ -407,9 +408,7 @@ func Init() {
 				hasV2Root = true
 				break
 			} else {
-				for k, v := range unifiedControllers {
-					cgControllers[k] = v
-				}
+				maps.Copy(cgControllers, unifiedControllers)
 			}
 		}
 

internal/server/cluster/config/config.go

@@ -3,6 +3,7 @@ package config
 import (
 	"context"
 	"fmt"
+	"maps"
 	"strconv"
 	"strings"
 	"time"
@@ -418,9 +419,7 @@ func (c *Config) Replace(values map[string]string) (map[string]string, error) {
 // Return what has actually changed.
 func (c *Config) Patch(patch map[string]string) (map[string]string, error) {
 	values := c.Dump() // Use current values as defaults
-	for name, value := range patch {
-		values[name] = value
-	}
+	maps.Copy(values, patch)
 
 	return c.update(values)
 }

internal/server/cluster/events.go

@@ -133,13 +133,7 @@ func ServerEventMode() EventMode {
 
 // RoleInSlice returns whether or not the rule is within the roles list.
 func RoleInSlice(role db.ClusterRole, roles []db.ClusterRole) bool {
-	for _, r := range roles {
-		if r == role {
-			return true
-		}
-	}
-
-	return false
+	return slices.Contains(roles, role)
 }
 
 // EventListenerWait waits for there to be listener connected to the specified address, or one of the event hubs

internal/server/cluster/gateway.go

@@ -865,7 +865,7 @@ func (g *Gateway) init(bootstrap bool) error {
 func (g *Gateway) WaitLeadership() error {
 	n := 80
 	sleep := 250 * time.Millisecond
-	for i := 0; i < n; i++ {
+	for range n {
 		g.lock.RLock()
 		isLeader, err := g.isLeader()
 		if err != nil {

internal/server/cluster/membership.go

@@ -843,7 +843,7 @@ assign:
 		}
 
 		notified := false
-		for i := 0; i < 10; i++ {
+		for range 10 {
 			time.Sleep(500 * time.Millisecond)
 			servers, err := local.Cluster(context.Background())
 			if err != nil {

internal/server/cluster/notify_test.go

@@ -151,13 +151,13 @@ type notifyFixtures struct {
 // cluster.https_address.
 func (h *notifyFixtures) Nodes(cert *localtls.CertInfo, n int) func() {
 	servers := make([]*httptest.Server, n)
-	for i := 0; i < n; i++ {
+	for i := range n {
 		servers[i] = newRestServer(cert)
 	}
 
 	// Insert new entries in the nodes table of the cluster database.
 	err := h.state.DB.Cluster.Transaction(context.TODO(), func(ctx context.Context, tx *db.ClusterTx) error {
-		for i := 0; i < n; i++ {
+		for i := range n {
 			name := strconv.Itoa(i)
 			address := servers[i].Listener.Addr().String()
 			var err error

internal/server/cluster/upgrade_test.go

@@ -73,7 +73,7 @@ func TestMaybeUpdate_Upgrade(t *testing.T) {
 	// Create a stub upgrade script that just touches a stamp file.
 	stamp := filepath.Join(dir, "stamp")
 	script := filepath.Join(dir, "cluster-upgrade")
-	data := []byte(fmt.Sprintf("#!/bin/sh\ntouch %s\n", stamp))
+	data := fmt.Appendf(nil, "#!/bin/sh\ntouch %s\n", stamp)
 	err = os.WriteFile(script, data, 0o755)
 	require.NoError(t, err)
 
@@ -126,7 +126,7 @@ func TestMaybeUpdate_NothingToDo(t *testing.T) {
 	// Create a stub upgrade script that just touches a stamp file.
 	stamp := filepath.Join(dir, "stamp")
 	script := filepath.Join(dir, "cluster-upgrade")
-	data := []byte(fmt.Sprintf("#!/bin/sh\ntouch %s\n", stamp))
+	data := fmt.Appendf(nil, "#!/bin/sh\ntouch %s\n", stamp)
 	err = os.WriteFile(script, data, 0o755)
 	require.NoError(t, err)
 

internal/server/db/cluster/entities.go

@@ -110,7 +110,7 @@ func URLToEntityType(rawURL string) (int, string, string, []string, error) {
 		// Make an []any for the number of expected path arguments and set each value in the slice to a *string.
 		nPathArgs := strings.Count(spaceSeparatedEntityPath, "%s")
 		pathArgsAny := make([]any, 0, nPathArgs)
-		for i := 0; i < nPathArgs; i++ {
+		for range nPathArgs {
 			var pathComponentStr string
 			pathArgsAny = append(pathArgsAny, &pathComponentStr)
 		}

internal/server/db/cluster/profiles.go

@@ -5,6 +5,7 @@ package cluster
 import (
 	"context"
 	"database/sql"
+	"maps"
 
 	"github.com/lxc/incus/v6/internal/server/device/config"
 	"github.com/lxc/incus/v6/shared/api"
@@ -132,15 +133,11 @@ func ExpandInstanceConfig(config map[string]string, profiles []api.Profile) map[
 	}
 
 	for i := range profileConfigs {
-		for k, v := range profileConfigs[i] {
-			expandedConfig[k] = v
-		}
+		maps.Copy(expandedConfig, profileConfigs[i])
 	}
 
 	// Stick the given config on top
-	for k, v := range config {
-		expandedConfig[k] = v
-	}
+	maps.Copy(expandedConfig, config)
 
 	return expandedConfig
 }
@@ -157,15 +154,11 @@ func ExpandInstanceDevices(devices config.Devices, profiles []api.Profile) confi
 	}
 
 	for i := range profileDevices {
-		for k, v := range profileDevices[i] {
-			expandedDevices[k] = v
-		}
+		maps.Copy(expandedDevices, profileDevices[i])
 	}
 
 	// Stick the given devices on top
-	for k, v := range devices {
-		expandedDevices[k] = v
-	}
+	maps.Copy(expandedDevices, devices)
 
 	return expandedDevices
 }

internal/server/db/cluster/update.go

@@ -2147,7 +2147,7 @@ func updateFromV42(ctx context.Context, tx *sql.Tx) error {
 		rowIDs := strings.Split(r.dupeRowIDs, ",")
 
 		// Iterate and delete all but 1 of the rowIDs so we leave just one left.
-		for i := 0; i < len(rowIDs)-1; i++ {
+		for i := range len(rowIDs) - 1 {
 			rowID, err := strconv.Atoi(rowIDs[i])
 			if err != nil {
 				return fmt.Errorf("Failed converting row ID: %w", err)
@@ -2213,7 +2213,7 @@ func updateFromV41(ctx context.Context, tx *sql.Tx) error {
 		rowIDs := strings.Split(r.dupeRowIDs, ",")
 
 		// Iterate and delete all but 1 of the rowIDs so we leave just one left.
-		for i := 0; i < len(rowIDs)-1; i++ {
+		for i := range len(rowIDs) - 1 {
 			rowID, err := strconv.Atoi(rowIDs[i])
 			if err != nil {
 				return fmt.Errorf("Failed converting row ID: %w", err)

internal/server/db/db.go

@@ -390,7 +390,7 @@ func (c *Cluster) Begin() (*sql.Tx, error) {
 }
 
 func begin(db *sql.DB) (*sql.Tx, error) {
-	for i := 0; i < 1000; i++ {
+	for range 1000 {
 		tx, err := db.Begin()
 		if err == nil {
 			return tx, nil