feat(logs): by default, log server activity to a file.

.gitignore

@@ -14,3 +14,6 @@ erupe-ce
 *.bin
 savedata/*/
 config.json
+
+# Logs
+logs/

README.md

@@ -223,6 +223,25 @@ Channel servers are configured under `Entrance.Entries[].Channels[]` with indivi
 }
 ```
 
+### Logging
+
+Erupe supports automatic file-based logging with rotation for production environments:
+
+```json
+{
+  "Logging": {
+    "LogToFile": true,                  // Enable file logging (default: true)
+    "LogFilePath": "logs/erupe.log",    // Log file path (default: "logs/erupe.log")
+    "LogMaxSize": 100,                  // Max file size in MB before rotation (default: 100)
+    "LogMaxBackups": 3,                 // Number of old log files to keep (default: 3)
+    "LogMaxAge": 28,                    // Max days to retain old logs (default: 28)
+    "LogCompress": true                 // Compress rotated logs (default: true)
+  }
+}
+```
+
+Logs are written to both console and file simultaneously. The log analyzer tool in `tools/loganalyzer/` provides commands to filter, analyze errors, track connections, and generate statistics from log files.
+
 ### In-game Commands
 
 Configure available commands and their prefixes:

config.example.json

@@ -42,6 +42,14 @@
     "BonusQuestAllowance": 3,
     "DailyQuestAllowance": 1
   },
+  "Logging": {
+    "LogToFile": true,
+    "LogFilePath": "logs/erupe.log",
+    "LogMaxSize": 100,
+    "LogMaxBackups": 3,
+    "LogMaxAge": 28,
+    "LogCompress": true
+  },
   "Discord": {
     "Enabled": false,
     "BotToken": "",

config/config.go

@@ -27,6 +27,7 @@ type Config struct {
 
 	DevModeOptions  DevModeOptions
 	GameplayOptions GameplayOptions
+	Logging         Logging
 	Discord         Discord
 	Commands        []Command
 	Courses         []Course
@@ -73,6 +74,16 @@ type GameplayOptions struct {
 	DailyQuestAllowance uint32 // Number of Daily Quests to allow daily
 }
 
+// Logging holds the logging configuration.
+type Logging struct {
+	LogToFile     bool   // Enable/disable file logging (default: true)
+	LogFilePath   string // File path for logs (default: "logs/erupe.log")
+	LogMaxSize    int    // Max size in MB before rotation (default: 100)
+	LogMaxBackups int    // Number of old log files to keep (default: 3)
+	LogMaxAge     int    // Max days to retain old logs (default: 28)
+	LogCompress   bool   // Compress rotated logs (default: true)
+}
+
 // Discord holds the discord integration config.
 type Discord struct {
 	Enabled           bool
@@ -197,6 +208,15 @@ func LoadConfig() (*Config, error) {
 		OutputDir: "savedata",
 	})
 
+	viper.SetDefault("Logging", Logging{
+		LogToFile:     true,
+		LogFilePath:   "logs/erupe.log",
+		LogMaxSize:    100,
+		LogMaxBackups: 3,
+		LogMaxAge:     28,
+		LogCompress:   true,
+	})
+
 	err := viper.ReadInConfig()
 	if err != nil {
 		return nil, err

go.mod

@@ -13,6 +13,7 @@ require (
 	golang.org/x/crypto v0.1.0
 	golang.org/x/exp v0.0.0-20221028150844-83b7d23a625f
 	golang.org/x/text v0.7.0
+	gopkg.in/natefinch/lumberjack.v2 v2.2.1
 )
 
 require (

go.sum

@@ -607,6 +607,8 @@ gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
 gopkg.in/ini.v1 v1.62.0 h1:duBzk771uxoUuOlyRLkHsygud9+5lrlGjdFBb4mSKDU=
 gopkg.in/ini.v1 v1.62.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
+gopkg.in/natefinch/lumberjack.v2 v2.2.1 h1:bBRl1b0OH9s/DuPhuXpNl+VtCaJXFZ5/uEFST95x9zc=
+gopkg.in/natefinch/lumberjack.v2 v2.2.1/go.mod h1:YD8tP3GAjkrDg1eZH7EGmyESg/lsYskCTPBJVb9jqSc=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.3/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

main.go

@@ -5,6 +5,7 @@ import (
 	"net"
 	"os"
 	"os/signal"
+	"path/filepath"
 	"runtime/debug"
 	"syscall"
 	"time"
@@ -19,6 +20,8 @@ import (
 	"github.com/jmoiron/sqlx"
 	_ "github.com/lib/pq"
 	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"gopkg.in/natefinch/lumberjack.v2"
 )
 
 // Temporary DB auto clean on startup for quick development & testing.
@@ -41,16 +44,76 @@ var Commit = func() string {
 	return "unknown"
 }
 
+// initLogger initializes the zap logger with file logging support
+func initLogger(cfg *config.Config) *zap.Logger {
+	var zapConfig zap.Config
+
+	// Base configuration based on DevMode
+	if cfg.DevMode {
+		zapConfig = zap.NewDevelopmentConfig()
+	} else {
+		zapConfig = zap.NewProductionConfig()
+	}
+
+	// Configure output paths
+	if cfg.Logging.LogToFile {
+		// Ensure the log directory exists
+		logDir := filepath.Dir(cfg.Logging.LogFilePath)
+		if err := os.MkdirAll(logDir, 0755); err != nil {
+			fmt.Printf("Failed to create log directory: %s\n", err)
+			os.Exit(1)
+		}
+
+		// Create lumberjack logger for file rotation
+		fileWriter := &lumberjack.Logger{
+			Filename:   cfg.Logging.LogFilePath,
+			MaxSize:    cfg.Logging.LogMaxSize,
+			MaxBackups: cfg.Logging.LogMaxBackups,
+			MaxAge:     cfg.Logging.LogMaxAge,
+			Compress:   cfg.Logging.LogCompress,
+		}
+
+		// Create encoder
+		encoderConfig := zapConfig.EncoderConfig
+		var encoder zapcore.Encoder
+		if cfg.DevMode {
+			encoder = zapcore.NewConsoleEncoder(encoderConfig)
+		} else {
+			encoder = zapcore.NewJSONEncoder(encoderConfig)
+		}
+
+		// Create cores for both console and file output
+		consoleCore := zapcore.NewCore(
+			encoder,
+			zapcore.AddSync(os.Stderr),
+			zapConfig.Level,
+		)
+		fileCore := zapcore.NewCore(
+			encoder,
+			zapcore.AddSync(fileWriter),
+			zapConfig.Level,
+		)
+
+		// Combine cores
+		core := zapcore.NewTee(consoleCore, fileCore)
+		logger := zap.New(core, zap.AddCaller(), zap.AddStacktrace(zapcore.ErrorLevel))
+		return logger
+	}
+
+	// File logging disabled, use default configuration
+	logger, err := zapConfig.Build()
+	if err != nil {
+		fmt.Printf("Failed to initialize logger: %s\n", err)
+		os.Exit(1)
+	}
+	return logger
+}
+
 func main() {
 	var err error
 
-	var zapLogger *zap.Logger
-	if config.ErupeConfig.DevMode {
-		zapLogger, _ = zap.NewDevelopment()
-	} else {
-		zapLogger, _ = zap.NewProduction()
-	}
-
+	// Initialize logger with file support
+	zapLogger := initLogger(config.ErupeConfig)
 	defer zapLogger.Sync()
 	logger := zapLogger.Named("main")
 

tools/loganalyzer/connections.go

@@ -54,7 +54,7 @@ type ConnectionStats struct {
 //   - Provides verbose session details including objects and stage changes
 //
 // Options:
-//   - f: Path to log file (default: "erupe.log")
+//   - f: Path to log file (default: "logs/erupe.log")
 //   - player: Filter sessions by player name (case-insensitive substring match)
 //   - sessions: Show individual player sessions
 //   - stats: Show connection statistics (default: true)
@@ -67,7 +67,7 @@ type ConnectionStats struct {
 func runConnections(args []string) {
 	fs := flag.NewFlagSet("connections", flag.ExitOnError)
 
-	logFile := fs.String("f", "erupe.log", "Path to log file")
+	logFile := fs.String("f", "logs/erupe.log", "Path to log file")
 	player := fs.String("player", "", "Filter by player name")
 	showSessions := fs.Bool("sessions", false, "Show individual player sessions")
 	showStats := fs.Bool("stats", true, "Show connection statistics")

tools/loganalyzer/errors.go

@@ -36,7 +36,7 @@ type ErrorGroup struct {
 //   - Tracks which callers produced each error
 //
 // Options:
-//   - f: Path to log file (default: "erupe.log")
+//   - f: Path to log file (default: "logs/erupe.log")
 //   - group: Group errors by "message", "caller", or "logger" (default: "message")
 //   - stack: Show stack traces in detailed view
 //   - limit: Maximum number of example entries per group (default: 10)
@@ -50,7 +50,7 @@ type ErrorGroup struct {
 func runErrors(args []string) {
 	fs := flag.NewFlagSet("errors", flag.ExitOnError)
 
-	logFile := fs.String("f", "erupe.log", "Path to log file")
+	logFile := fs.String("f", "logs/erupe.log", "Path to log file")
 	groupBy := fs.String("group", "message", "Group errors by: message, caller, or logger")
 	showStack := fs.Bool("stack", false, "Show stack traces")
 	limit := fs.Int("limit", 10, "Limit number of examples per error group")

tools/loganalyzer/filter.go

@@ -29,7 +29,7 @@ import (
 func runFilter(args []string) {
 	fs := flag.NewFlagSet("filter", flag.ExitOnError)
 
-	logFile := fs.String("f", "erupe.log", "Path to log file")
+	logFile := fs.String("f", "logs/erupe.log", "Path to log file")
 	level := fs.String("level", "", "Filter by log level (info, warn, error, fatal)")
 	logger := fs.String("logger", "", "Filter by logger name (supports wildcards)")
 	message := fs.String("msg", "", "Filter by message content (case-insensitive)")

tools/loganalyzer/stats.go

@@ -44,7 +44,7 @@ type LogStats struct {
 // patterns, peak usage times, and potential issues.
 //
 // Options:
-//   - f: Path to log file (default: "erupe.log")
+//   - f: Path to log file (default: "logs/erupe.log")
 //   - top: Number of top items to show in detailed view (default: 10)
 //   - detailed: Show detailed statistics including temporal patterns and top messages
 //
@@ -55,7 +55,7 @@ type LogStats struct {
 func runStats(args []string) {
 	fs := flag.NewFlagSet("stats", flag.ExitOnError)
 
-	logFile := fs.String("f", "erupe.log", "Path to log file")
+	logFile := fs.String("f", "logs/erupe.log", "Path to log file")
 	topN := fs.Int("top", 10, "Show top N messages/loggers")
 	detailed := fs.Bool("detailed", false, "Show detailed statistics")
 

tools/loganalyzer/tail.go

@@ -21,7 +21,7 @@ import (
 // Both phases support filtering by log level and colorized output.
 //
 // Options:
-//   - f: Path to log file (default: "erupe.log")
+//   - f: Path to log file (default: "logs/erupe.log")
 //   - n: Number of initial lines to show (default: 10)
 //   - follow: Whether to continue following the file (default: true)
 //   - level: Filter by log level (info, warn, error, fatal)
@@ -37,7 +37,7 @@ import (
 func runTail(args []string) {
 	fs := flag.NewFlagSet("tail", flag.ExitOnError)
 
-	logFile := fs.String("f", "erupe.log", "Path to log file")
+	logFile := fs.String("f", "logs/erupe.log", "Path to log file")
 	lines := fs.Int("n", 10, "Number of initial lines to show")
 	follow := fs.Bool("follow", true, "Follow the log file (like tail -f)")
 	level := fs.String("level", "", "Filter by log level")