Replace zerolog with log/slog from stdlib

- Rewrite logger package to use slog with LevelVar for dynamic levels
- Update all packages to use *slog.Logger instead of *zerolog.Logger
- Use TextHandler for TTY (dev), JSONHandler for production
- Add make check target (runs lint + test)
- Add make test target

internal/logger/logger.go

@@ -1,12 +1,10 @@
 package logger
 
 import (
-	"io"
+	"log/slog"
 	"os"
-	"time"
 
 	"git.eeqj.de/sneak/gohttpserver/internal/globals"
-	"github.com/rs/zerolog"
 	"go.uber.org/fx"
 )
 
@@ -16,82 +14,56 @@ type LoggerParams struct {
 }
 
 type Logger struct {
-	log    *zerolog.Logger
+	log    *slog.Logger
+	level  *slog.LevelVar
 	params LoggerParams
 }
 
 func New(lc fx.Lifecycle, params LoggerParams) (*Logger, error) {
 	l := new(Logger)
+	l.level = new(slog.LevelVar)
+	l.level.Set(slog.LevelInfo)
 
-	// always log in UTC
-	zerolog.TimestampFunc = func() time.Time {
-		return time.Now().UTC()
-	}
-	zerolog.SetGlobalLevel(zerolog.InfoLevel)
-
+	// TTY detection for dev vs prod output
 	tty := false
 	if fileInfo, _ := os.Stdout.Stat(); (fileInfo.Mode() & os.ModeCharDevice) != 0 {
 		tty = true
 	}
 
-	var writers []io.Writer
-
+	var handler slog.Handler
 	if tty {
-		// this does cool colorization for console/dev
-		consoleWriter := zerolog.NewConsoleWriter(
-			func(w *zerolog.ConsoleWriter) {
-				// Customize time format
-				w.TimeFormat = time.RFC3339Nano
-			},
-		)
-
-		writers = append(writers, consoleWriter)
+		// Text output for development
+		handler = slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
+			Level:     l.level,
+			AddSource: true,
+		})
 	} else {
-		// log json in prod for the machines
-		writers = append(writers, os.Stdout)
+		// JSON output for production
+		handler = slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
+			Level:     l.level,
+			AddSource: true,
+		})
 	}
 
-	/*
-		// this is how you log to a file, if you do that
-		// sort of thing still
-		logfile := viper.GetString("Logfile")
-		if logfile != "" {
-		    logfileDir := filepath.Dir(logfile)
-		    err := goutil.Mkdirp(logfileDir)
-		    if err != nil {
-			    log.Error().Err(err).Msg("unable to create log dir")
-		    }
-
-		    hp.logfh, err = os.OpenFile(logfile, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644)
-		    if err != nil {
-			    panic("unable to open logfile: " + err.Error())
-		    }
-
-		    writers = append(writers, hp.logfh)
-	*/
-
-	multi := zerolog.MultiLevelWriter(writers...)
-	logger := zerolog.New(multi).With().Timestamp().Logger().With().Caller().Logger()
-
-	l.log = &logger
-	// log.Logger = logger
+	l.log = slog.New(handler)
+	l.params = params
 
 	return l, nil
 }
 
 func (l *Logger) EnableDebugLogging() {
-	zerolog.SetGlobalLevel(zerolog.DebugLevel)
-	l.log.Debug().Bool("debug", true).Send()
+	l.level.Set(slog.LevelDebug)
+	l.log.Debug("debug logging enabled", "debug", true)
 }
 
-func (l *Logger) Get() *zerolog.Logger {
+func (l *Logger) Get() *slog.Logger {
 	return l.log
 }
 
 func (l *Logger) Identify() {
-	l.log.Info().
-		Str("appname", l.params.Globals.Appname).
-		Str("version", l.params.Globals.Version).
-		Str("buildarch", l.params.Globals.Buildarch).
-		Msg("starting")
+	l.log.Info("starting",
+		"appname", l.params.Globals.Appname,
+		"version", l.params.Globals.Version,
+		"buildarch", l.params.Globals.Buildarch,
+	)
 }