Set up structured logging and Lumberjack log rotation

go.mod

@@ -1,3 +1,5 @@
 module git.systemact.nl/henk/mars-terraform-registry
 
 go 1.26.2
+
+require gopkg.in/natefinch/lumberjack.v2 v2.2.1

go.sum

@@ -0,0 +1,2 @@
+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=

main.go

@@ -1,5 +1,39 @@
 package main
 
-func main() {
+import (
+	"io"
+	"log/slog"
+	"os"
 
+	"gopkg.in/natefinch/lumberjack.v2"
+)
+
+func main() {
+	logBaseDir, err := os.UserHomeDir()
+	if err != nil {
+		panic("Can't determine home directory")
+	}
+	logFilePath := logBaseDir + "/.local/share/mars_terraform_registry/logs"
+	if err := os.MkdirAll(logFilePath, 0755); err != nil {
+		panic("Can't create log directory")
+	}
+
+	// Create Lumberjack rolling logger (replaces *os.File)
+	logFile := &lumberjack.Logger{
+		Filename:   logFilePath,
+		MaxSize:    10,   // MB: size at which to rotate
+		MaxAge:     30,   // Days: how long to keep old logs
+		MaxBackups: 5,    // Number of old logs to keep
+		Compress:   true, // .gz compression for old logs
+		LocalTime:  true, // Local time instead of UTC in filenames
+	}
+
+	defer logFile.Close()
+	multiWriter := io.MultiWriter(os.Stdout, logFile)
+
+	logOptions := slog.HandlerOptions{
+		Level: slog.LevelDebug,
+	}
+	slog.SetDefault(slog.New(slog.NewJSONHandler(multiWriter, &logOptions)))
+	slog.Info("Logging test")
 }