Add HostMatch field and related functionality in Ruleset and Server

The Ruleset struct has been updated to include a 'HostMatch' field. A corresponding conditional block to handle 'HostMatch' was added in the 'Server' object's ruleset cycle. This allows the rules to include host-specific matches and debug information about matches found. Further expansion of this functionality can enable detailed rule application based on the target host.

rule.go

@@ -18,9 +18,15 @@ type Ruleset struct {
 	Rule []struct {
 		ID        string         `fig:"id" validate:"required"`
 		Regexp    *regexp.Regexp `fig:"regexp" validate:"required"`
+		HostMatch *string        `fig:"host_match"`
 	} `fig:"rule"`
 }
 
+// NewRuleset initializes a new Ruleset based on the provided Config.
+// It reads the rule file specified in the Config, validates the file's
+// existence, and loads the Ruleset using the fig library.
+// It checks for duplicate rules and returns an error if any duplicates are found.
+// If all operations are successful, it returns the created Ruleset and no error.
 func NewRuleset(c *Config) (*Ruleset, error) {
 	rs := &Ruleset{}
 	p := filepath.Dir(c.Server.RuleFile)

server.go

@@ -71,6 +71,15 @@ func (s *Server) Run() error {
 	s.ruleset = rs
 	for _, r := range rs.Rule {
 		s.log.Debug("found rule", slog.String("ID", r.ID))
+		if r.HostMatch != nil {
+			s.log.Debug("host match enabled", slog.String("host", *r.HostMatch))
+		}
+		if r.Regexp != nil {
+			foo := r.Regexp.FindAllStringSubmatch("test_foo23", -1)
+			if len(foo) > 0 {
+				s.log.Debug("matched", slog.Any("groups", foo))
+			}
+		}
 	}
 
 	return s.RunWithListener(l)