[client,management] add netflow support to client and update management (#3414)

adds NetFlow functionality to track and log network traffic information between peers, with features including:

- Flow logging for TCP, UDP, and ICMP traffic
- Integration with connection tracking system
- Resource ID tracking in NetFlow events
- DNS and exit node collection configuration
- Flow API and Redis cache in management
- Memory-based flow storage implementation
- Kernel conntrack counters and userspace counters
- TCP state machine improvements for more accurate tracking
- Migration from net.IP to netip.Addr in the userspace firewall

management/server/cache/store.go

@@ -0,0 +1,50 @@
+package cache
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/eko/gocache/lib/v4/store"
+	gocache_store "github.com/eko/gocache/store/go_cache/v4"
+	redis_store "github.com/eko/gocache/store/redis/v4"
+	gocache "github.com/patrickmn/go-cache"
+	"github.com/redis/go-redis/v9"
+)
+
+// RedisStoreEnvVar is the environment variable that determines if a redis store should be used.
+// The value should follow redis URL format. https://github.com/redis/redis-specifications/blob/master/uri/redis.txt
+const RedisStoreEnvVar = "NB_IDP_CACHE_REDIS_ADDRESS"
+
+// NewStore creates a new cache store with the given max timeout and cleanup interval. It checks for the environment Variable RedisStoreEnvVar
+// to determine if a redis store should be used. If the environment variable is set, it will attempt to connect to the redis store.
+func NewStore(maxTimeout, cleanupInterval time.Duration) (store.StoreInterface, error) {
+	redisAddr := os.Getenv(RedisStoreEnvVar)
+	if redisAddr != "" {
+		return getRedisStore(redisAddr)
+	}
+	goc := gocache.New(maxTimeout, cleanupInterval)
+	return gocache_store.NewGoCache(goc), nil
+}
+
+func getRedisStore(redisEnvAddr string) (store.StoreInterface, error) {
+	options, err := redis.ParseURL(redisEnvAddr)
+	if err != nil {
+		return nil, fmt.Errorf("parsing redis cache url: %s", err)
+	}
+
+	options.MaxIdleConns = 6
+	options.MinIdleConns = 3
+	options.MaxActiveConns = 100
+	redisClient := redis.NewClient(options)
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+
+	_, err = redisClient.Ping(ctx).Result()
+	if err != nil {
+		return nil, err
+	}
+
+	return redis_store.NewRedis(redisClient), nil
+}