Add structured container-friendly logging

logger.go

@@ -0,0 +1,36 @@
+package reforger_utils
+
+import (
+	"log/slog"
+	"os"
+	"sync"
+)
+
+var (
+	loggerMu sync.RWMutex
+	logger   = newDefaultLogger()
+)
+
+func newDefaultLogger() *slog.Logger {
+	return slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelInfo}))
+}
+
+// SetLogger configures the package logger.
+// Passing nil resets it to the default JSON logger writing to stdout.
+func SetLogger(l *slog.Logger) {
+	loggerMu.Lock()
+	defer loggerMu.Unlock()
+
+	if l == nil {
+		logger = newDefaultLogger()
+		return
+	}
+
+	logger = l
+}
+
+func getLogger() *slog.Logger {
+	loggerMu.RLock()
+	defer loggerMu.RUnlock()
+	return logger
+}