feat: changeable pat rate limiting

management/server/http/middleware/rate_limiter.go

@@ -4,14 +4,27 @@ import (
 	"context"
 	"net"
 	"net/http"
+	"os"
+	"strconv"
 	"sync"
+	"sync/atomic"
 	"time"
 
+	log "github.com/sirupsen/logrus"
 	"golang.org/x/time/rate"
 
 	"github.com/netbirdio/netbird/shared/management/http/util"
 )
 
+const (
+	RateLimitingEnabledEnv = "NB_API_RATE_LIMITING_ENABLED"
+	RateLimitingBurstEnv   = "NB_API_RATE_LIMITING_BURST"
+	RateLimitingRPMEnv     = "NB_API_RATE_LIMITING_RPM"
+
+	defaultAPIRPM   = 6
+	defaultAPIBurst = 500
+)
+
 // RateLimiterConfig holds configuration for the API rate limiter
 type RateLimiterConfig struct {
 	// RequestsPerMinute defines the rate at which tokens are replenished
@@ -34,6 +47,35 @@ func DefaultRateLimiterConfig() *RateLimiterConfig {
 	}
 }
 
+func RateLimiterConfigFromEnv() (cfg *RateLimiterConfig, enabled bool) {
+	rpm := defaultAPIRPM
+	if v := os.Getenv(RateLimitingRPMEnv); v != "" {
+		value, err := strconv.Atoi(v)
+		if err != nil {
+			log.Warnf("parsing %s env var: %v, using default %d", RateLimitingRPMEnv, err, rpm)
+		} else {
+			rpm = value
+		}
+	}
+
+	burst := defaultAPIBurst
+	if v := os.Getenv(RateLimitingBurstEnv); v != "" {
+		value, err := strconv.Atoi(v)
+		if err != nil {
+			log.Warnf("parsing %s env var: %v, using default %d", RateLimitingBurstEnv, err, burst)
+		} else {
+			burst = value
+		}
+	}
+
+	return &RateLimiterConfig{
+		RequestsPerMinute: float64(rpm),
+		Burst:             burst,
+		CleanupInterval:   6 * time.Hour,
+		LimiterTTL:        24 * time.Hour,
+	}, os.Getenv(RateLimitingEnabledEnv) == "true"
+}
+
 // limiterEntry holds a rate limiter and its last access time
 type limiterEntry struct {
 	limiter    *rate.Limiter
@@ -46,6 +88,7 @@ type APIRateLimiter struct {
 	limiters map[string]*limiterEntry
 	mu       sync.RWMutex
 	stopChan chan struct{}
+	enabled  atomic.Bool
 }
 
 // NewAPIRateLimiter creates a new API rate limiter with the given configuration
@@ -59,14 +102,49 @@ func NewAPIRateLimiter(config *RateLimiterConfig) *APIRateLimiter {
 		limiters: make(map[string]*limiterEntry),
 		stopChan: make(chan struct{}),
 	}
+	rl.enabled.Store(true)
 
 	go rl.cleanupLoop()
 
 	return rl
 }
 
+func (rl *APIRateLimiter) SetEnabled(enabled bool) {
+	rl.enabled.Store(enabled)
+}
+
+func (rl *APIRateLimiter) Enabled() bool {
+	return rl.enabled.Load()
+}
+
+func (rl *APIRateLimiter) UpdateConfig(config *RateLimiterConfig) {
+	if config == nil {
+		return
+	}
+
+	newRPS := rate.Limit(config.RequestsPerMinute / 60.0)
+	newBurst := config.Burst
+
+	rl.mu.Lock()
+	rl.config.RequestsPerMinute = config.RequestsPerMinute
+	rl.config.Burst = newBurst
+	snapshot := make([]*rate.Limiter, 0, len(rl.limiters))
+	for _, entry := range rl.limiters {
+		snapshot = append(snapshot, entry.limiter)
+	}
+	rl.mu.Unlock()
+
+	for _, l := range snapshot {
+		l.SetLimit(newRPS)
+		l.SetBurst(newBurst)
+	}
+}
+
 // Allow checks if a request for the given key (token) is allowed
 func (rl *APIRateLimiter) Allow(key string) bool {
+	if !rl.enabled.Load() {
+		return true
+	}
 	limiter := rl.getLimiter(key)
 	return limiter.Allow()
 }
@@ -74,6 +152,9 @@ func (rl *APIRateLimiter) Allow(key string) bool {
 // Wait blocks until the rate limiter allows another request for the given key
 // Returns an error if the context is canceled
 func (rl *APIRateLimiter) Wait(ctx context.Context, key string) error {
+	if !rl.enabled.Load() {
+		return nil
+	}
 	limiter := rl.getLimiter(key)
 	return limiter.Wait(ctx)
 }
@@ -153,6 +234,10 @@ func (rl *APIRateLimiter) Reset(key string) {
 // Returns 429 Too Many Requests if the rate limit is exceeded.
 func (rl *APIRateLimiter) Middleware(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if !rl.enabled.Load() {
+			next.ServeHTTP(w, r)
+			return
+		}
 		clientIP := getClientIP(r)
 		if !rl.Allow(clientIP) {
 			util.WriteErrorResponse("rate limit exceeded, please try again later", http.StatusTooManyRequests, w)