feat: rule set loader

Add rule set loader, move original config loader routine into
ruleset/loader.go

cmd/root.go

@@ -7,7 +7,6 @@ import (
 	"os/signal"
 	"strconv"
 	"strings"
-	"syscall"
 
 	"github.com/apernet/OpenGFW/analyzer"
 	"github.com/apernet/OpenGFW/analyzer/tcp"
@@ -284,31 +283,13 @@ func runMain(cmd *cobra.Command, args []string) {
 		logger.Info("shutting down gracefully...")
 		cancelFunc()
 	}()
-	go func() {
-		// Rule reload
-		reloadChan := make(chan os.Signal)
-		signal.Notify(reloadChan, syscall.SIGHUP)
-		for {
-			<-reloadChan
-			logger.Info("reloading rules")
-			rawRs, err := ruleset.ExprRulesFromYAML(args[0])
-			if err != nil {
-				logger.Error("failed to load rules, using old rules", zap.Error(err))
-				continue
+
+	rsLoader := ruleset.NewSignalRuleSetLoader(args[0], func(rs ruleset.Ruleset) error {
+		return en.UpdateRuleset(rs)
+	}, analyzers, modifiers, rsConfig)
+	if err := rsLoader.Start(); err != nil {
+		logger.Error("start ruleset loader failed", zap.Error(err))
 	}
-			rs, err := ruleset.CompileExprRules(rawRs, analyzers, modifiers, rsConfig)
-			if err != nil {
-				logger.Error("failed to compile rules, using old rules", zap.Error(err))
-				continue
-			}
-			err = en.UpdateRuleset(rs)
-			if err != nil {
-				logger.Error("failed to update ruleset", zap.Error(err))
-			} else {
-				logger.Info("rules reloaded")
-			}
-		}
-	}()
 
 	logger.Info("engine started")
 	logger.Info("engine exited", zap.Error(en.Run(ctx)))

ruleset/loader.go

@@ -0,0 +1,72 @@
+package ruleset
+
+import (
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+
+	"github.com/apernet/OpenGFW/analyzer"
+	"github.com/apernet/OpenGFW/modifier"
+	"go.uber.org/zap"
+)
+
+type RuleSetHandler func(Ruleset) error
+
+type RuleSetLoader interface {
+	Start() error
+}
+
+type SignalRuleSetLoader struct {
+	o          sync.Once
+	filePath   string
+	handler    RuleSetHandler
+	reloadChan chan os.Signal
+	analyzers  []analyzer.Analyzer
+	modifiers  []modifier.Modifier
+	config     *BuiltinConfig
+	logger     *zap.Logger
+}
+
+func NewSignalRuleSetLoader(path string, handler RuleSetHandler, ans []analyzer.Analyzer, mods []modifier.Modifier, cfg *BuiltinConfig) RuleSetLoader {
+	return &SignalRuleSetLoader{
+		o:          sync.Once{},
+		filePath:   path,
+		handler:    handler,
+		reloadChan: make(chan os.Signal),
+		analyzers:  ans,
+		modifiers:  mods,
+		config:     cfg,
+	}
+}
+
+func (l *SignalRuleSetLoader) Start() error {
+	l.o.Do(
+		func() {
+			signal.Notify(l.reloadChan, syscall.SIGHUP)
+			go func() {
+				for {
+					<-l.reloadChan
+					l.logger.Info("reloading rules")
+					rawRs, err := ExprRulesFromYAML(l.filePath)
+					if err != nil {
+						l.logger.Error("failed to load rules, using old rules", zap.Error(err))
+						continue
+					}
+					rs, err := CompileExprRules(rawRs, l.analyzers, l.modifiers, l.config)
+					if err != nil {
+						l.logger.Error("failed to compile rules, using old rules", zap.Error(err))
+						continue
+					}
+					err = l.handler(rs)
+					if err != nil {
+						l.logger.Error("failed to update ruleset", zap.Error(err))
+					} else {
+						l.logger.Info("rules reloaded")
+					}
+				}
+			}()
+		},
+	)
+	return nil
+}