feat: add metrics support

cmd/banforge/command/daemon.go

@@ -60,6 +60,11 @@ var DaemonCmd = &cobra.Command{
 			log.Error("Failed to load config", "error", err)
 			os.Exit(1)
 		}
+		_, err = config.LoadMetricsConfig()
+		if err != nil {
+			log.Error("Failed to load metrics config", "error", err)
+			os.Exit(1)
+		}
 		var b blocker.BlockerEngine
 		fw := cfg.Firewall.Name
 		b = blocker.GetBlocker(fw, cfg.Firewall.Config)

internal/config/appconf.go

@@ -3,15 +3,31 @@ package config
 import (
 	"errors"
 	"fmt"
+	"github.com/BurntSushi/toml"
+	"github.com/d3m0k1d/BanForge/internal/logger"
+	"github.com/d3m0k1d/BanForge/internal/metrics"
 	"os"
 	"strconv"
 	"strings"
 	"time"
-
-	"github.com/BurntSushi/toml"
-	"github.com/d3m0k1d/BanForge/internal/logger"
 )
 
+func LoadMetricsConfig() (*Metrics, error) {
+	cfg := &Metrics{}
+	_, err := toml.DecodeFile("/etc/banforge/config.toml", cfg)
+	if err != nil {
+		return nil, fmt.Errorf("failed to decode config: %w", err)
+	}
+
+	if cfg.Enabled && cfg.Port > 0 && cfg.Port < 65535 {
+		go metrics.StartMetricsServer(cfg.Port)
+	} else if cfg.Enabled {
+		fmt.Println("Metrics enabled but port invalid, not starting server")
+	}
+
+	return cfg, nil
+}
+
 func LoadRuleConfig() ([]Rule, error) {
 	log := logger.New(false)
 	var cfg Rules

internal/config/template.go

@@ -8,6 +8,10 @@ const Base_config = `
 name = ""
 config = "/etc/nftables.conf"
 
+[metrics]
+enabled = false
+port = 2122
+
 [[service]]
 name = "nginx"
 logging = "file"

internal/config/types.go

@@ -14,6 +14,7 @@ type Service struct {
 
 type Config struct {
 	Firewall Firewall  `toml:"firewall"`
+	Metrics  Metrics   `toml:"metrics"`
 	Service  []Service `toml:"service"`
 }
 
@@ -31,3 +32,8 @@ type Rule struct {
 	MaxRetry    int    `toml:"max_retry"`
 	BanTime     string `toml:"ban_time"`
 }
+
+type Metrics struct {
+	Enabled bool `toml:"enabled"`
+	Port    int  `toml:"port"`
+}

internal/metrics/metrics.go

@@ -0,0 +1,65 @@
+package metrics
+
+import (
+	"fmt"
+	"net/http"
+	"sync"
+)
+
+var (
+	metricsMu sync.RWMutex
+	metrics   = make(map[string]int64)
+)
+
+func IncBan(service string) {
+	metricsMu.Lock()
+	metrics["ban_count"]++
+	metrics[service+"_bans"]++
+	metricsMu.Unlock()
+}
+
+func IncUnban(service string) {
+	metricsMu.Lock()
+	metrics["unban_count"]++
+	metrics[service+"_unbans"]++
+	metricsMu.Unlock()
+}
+
+func IncRuleMatched(rule_name string) {
+	metricsMu.Lock()
+	metrics[rule_name+"_rule_matched"]++
+	metricsMu.Unlock()
+}
+
+func IncLogParsed() {
+	metricsMu.Lock()
+	metrics["log_parsed"]++
+	metricsMu.Unlock()
+}
+
+func MetricsHandler() http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+
+		metricsMu.RLock()
+		snapshot := make(map[string]int64, len(metrics))
+		for k, v := range metrics {
+			snapshot[k] = v
+		}
+		metricsMu.RUnlock()
+
+		w.Header().Set("Content-Type", "text/plain; version=0.0.4")
+
+		for name, value := range snapshot {
+			metricName := name + "_total"
+			fmt.Fprintf(w, "# TYPE %s counter\n", metricName)
+			fmt.Fprintf(w, "%s %d\n", metricName, value)
+		}
+	})
+}
+func StartMetricsServer(port int) {
+	http.Handle("/metrics", MetricsHandler())
+	addr := fmt.Sprintf(":%d", port)
+	if err := http.ListenAndServe(addr, nil); err != nil {
+	}
+}
+

internal/metrics/server.go

@@ -0,0 +1,14 @@
+package metrics
+
+import (
+	"net/http"
+)
+
+func Handler() http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/plain")
+		for k, v := range metrics {
+			w.Write([]byte(k + " " + string(v) + "\n"))
+		}
+	})
+}