chore: migrate from go-kit/log to log/slog (#1572)

* fix(deps): update module github.com/fclairamb/ftpserverlib to v0.28.0
* chore: migrate from go-kit/log to log/slog

Replace all logging infrastructure from github.com/go-kit/log and
github.com/fclairamb/go-log with Go's standard library log/slog.

Changes:
- Replace all log.Logger interfaces with *slog.Logger throughout codebase
- Update main.go to use slog.Default() and slog.New() directly
- Update server, config, and all fs packages to use *slog.Logger
- Remove go-kit/log dependency completely
- Remove direct usage of go-log abstraction layer
- Set logger to nil for afero-snd and afero-gdrive integrations

The go-log package remains as an indirect dependency (required by
afero-snd) but is no longer imported or used directly in the codebase.

All tests pass and build succeeds.

Author: fclairamb

config/config.go

@@ -6,10 +6,9 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"log/slog"
 	"os"
 
-	log "github.com/fclairamb/go-log"
-
 	"github.com/fclairamb/ftpserver/config/confpar"
 	"github.com/fclairamb/ftpserver/fs"
 
@@ -24,12 +23,12 @@ var ErrUnknownUser = errors.New("unknown user")
 // Config provides the general server config
 type Config struct {
 	fileName string
-	logger   log.Logger
+	logger   *slog.Logger
 	Content  *confpar.Content
 }
 
 // NewConfig creates a new config instance
-func NewConfig(fileName string, logger log.Logger) (*Config, error) {
+func NewConfig(fileName string, logger *slog.Logger) (*Config, error) {
 	if fileName == "" {
 		fileName = "ftpserver.json"
 	}
@@ -48,7 +47,7 @@ func NewConfig(fileName string, logger log.Logger) (*Config, error) {
 
 // FromContent creates a new config instance from a pre-created Content and logger. The
 // fileName should indicate origin of the given Content, but the file will never be opened.
-func FromContent(content *confpar.Content, fileName string, logger log.Logger) (*Config, error) {
+func FromContent(content *confpar.Content, fileName string, logger *slog.Logger) (*Config, error) {
 	c := &Config{
 		fileName: fileName,
 		logger:   logger,

fs/fs.go

@@ -3,9 +3,9 @@ package fs
 
 import (
 	"fmt"
+	"log/slog"
 
 	snd "github.com/fclairamb/afero-snd"
-	log "github.com/fclairamb/go-log"
 	"github.com/spf13/afero"
 
 	"github.com/fclairamb/ftpserver/config/confpar"
@@ -30,7 +30,7 @@ func (err UnsupportedFsError) Error() string {
 }
 
 // LoadFs loads a file system from an access description
-func LoadFs(access *confpar.Access, logger log.Logger) (afero.Fs, error) {
+func LoadFs(access *confpar.Access, logger *slog.Logger) (afero.Fs, error) {
 	var fs afero.Fs
 	var err error
 
@@ -72,7 +72,7 @@ func LoadFs(access *confpar.Access, logger log.Logger) (afero.Fs, error) {
 		fs, err = snd.NewFs(&snd.Config{
 			Destination: fs,
 			Temporary:   temp,
-			Logger:      logger.With("component", "snd"),
+			Logger:      nil,
 		})
 	}
 

fs/fslog/fslog.go

@@ -2,29 +2,28 @@
 package fslog
 
 import (
+	"log/slog"
 	"os"
 	"time"
 
 	"github.com/spf13/afero"
-
-	log "github.com/fclairamb/go-log"
 )
 
 // File is a wrapper to log interactions around file accesses
 type File struct {
-	src           afero.File // Source file
-	logger        log.Logger // Associated logger
-	lengthRead    int        // Length read
-	lengthWritten int        // Length written
+	src           afero.File   // Source file
+	logger        *slog.Logger // Associated logger
+	lengthRead    int          // Length read
+	lengthWritten int          // Length written
 }
 
 // Fs is a wrapper to log interactions around file system accesses
 type Fs struct {
-	src    afero.Fs   // Source file system
-	logger log.Logger // Associated logger
+	src    afero.Fs     // Source file system
+	logger *slog.Logger // Associated logger
 }
 
-func logErr(logger log.Logger, err error) log.Logger {
+func logErr(logger *slog.Logger, err error) *slog.Logger {
 	if err != nil {
 		return logger.With("err", err, "failed", true)
 	}
@@ -234,7 +233,7 @@ func (f *File) WriteString(str string) (int, error) {
 }
 
 // LoadFS creates an instance with logging
-func LoadFS(src afero.Fs, logger log.Logger) (afero.Fs, error) {
+func LoadFS(src afero.Fs, logger *slog.Logger) (afero.Fs, error) {
 	return &Fs{
 		src:    src,
 		logger: logger,

fs/gdrive/gdrive.go

@@ -5,11 +5,11 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"log/slog"
 	"os"
 
 	drv "github.com/fclairamb/afero-gdrive"
 	drvoa "github.com/fclairamb/afero-gdrive/oauthhelper"
-	log "github.com/fclairamb/go-log"
 	"github.com/spf13/afero"
 	"golang.org/x/oauth2"
 
@@ -22,7 +22,7 @@ import (
 var ErrMissingGoogleClientCredentials = errors.New("missing the google client credentials")
 
 // LoadFs loads a file system from an access description
-func LoadFs(access *confpar.Access, logger log.Logger) (afero.Fs, error) {
+func LoadFs(access *confpar.Access, logger *slog.Logger) (afero.Fs, error) {
 	googleClientID := access.Params["google_client_id"]
 	googleClientSecret := access.Params["google_client_secret"]
 	tokenFile := access.Params["token_file"]
@@ -91,8 +91,6 @@ func LoadFs(access *confpar.Access, logger log.Logger) (afero.Fs, error) {
 		return nil, err
 	}
 
-	gdriveFs.Logger = logger
-
 	// Allowing to set the basePath in the driver
 	if basePath != "" {
 		basePath = utils.ReplaceEnvVars(basePath)

fs/telegram/telegram.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log/slog"
 	"path/filepath"
 	"strconv"
 	"strings"
@@ -13,7 +14,6 @@ import (
 	"sync/atomic"
 	"time"
 
-	log "github.com/fclairamb/go-log"
 	tele "gopkg.in/telebot.v3"
 
 	"github.com/spf13/afero"
@@ -38,7 +38,7 @@ type Fs struct {
 	// ChatID is the telegram chat ID to send files to
 	ChatID int64
 	// Logger is the logger, obviously
-	Logger log.Logger
+	Logger *slog.Logger
 
 	// fakeFs is a lightweight fake filesystem intended for store temporary info about files
 	// since some ftp clients expect to perform mkdir() + stat() on files and directories before upload
@@ -70,7 +70,7 @@ var textExtensions = []string{".txt", ".md"}
 var audioExtensions = []string{".mp3", ".ogg", ".flac", ".wav", ".m4a", ".opus"}
 
 // LoadFs loads a file system from an access description
-func LoadFs(access *confpar.Access, logger log.Logger) (afero.Fs, error) {
+func LoadFs(access *confpar.Access, logger *slog.Logger) (afero.Fs, error) {
 
 	token := access.Params["Token"]
 	if token == "" {

go.mod

@@ -1,6 +1,6 @@
 module github.com/fclairamb/ftpserver
 
-go 1.24.0
+go 1.25.0
 
 toolchain go1.25.5
 
@@ -12,8 +12,7 @@ require (
 	github.com/fclairamb/afero-gdrive v0.3.0
 	github.com/fclairamb/afero-s3 v0.3.1
 	github.com/fclairamb/afero-snd v0.1.0
-	github.com/fclairamb/ftpserverlib v0.27.1
-	github.com/fclairamb/go-log v0.6.0
+	github.com/fclairamb/ftpserverlib v0.28.0
 	github.com/go-crypt/crypt v0.4.7
 	github.com/go-mail/mail v2.3.1+incompatible
 	github.com/pkg/sftp v1.13.10
@@ -59,7 +58,6 @@ require (
 	github.com/tidwall/gjson v1.14.4 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/tidwall/pretty v1.2.1 // indirect
-	github.com/zeebo/errs v1.4.0 // indirect
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
 	go.opentelemetry.io/contrib/detectors/gcp v1.38.0 // indirect
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.63.0 // indirect
@@ -78,8 +76,7 @@ require (
 
 require (
 	github.com/dropbox/dropbox-sdk-go-unofficial v5.6.0+incompatible // indirect
-	github.com/go-kit/log v0.2.1
-	github.com/go-logfmt/logfmt v0.6.0 // indirect
+	github.com/fclairamb/go-log v0.6.0 // indirect
 	github.com/googleapis/enterprise-certificate-proxy v0.3.7 // indirect
 	github.com/googleapis/gax-go/v2 v2.15.0 // indirect
 	github.com/jmespath/go-jmespath v0.4.0 // indirect