Replace Redis dependency with a generic cache store for fast path flag handling

management/internals/server/boot.go

@@ -164,7 +164,7 @@ func (s *BaseServer) GRPCServer() *grpc.Server {
 
 		gRPCAPIHandler := grpc.NewServer(gRPCOpts...)
 		peerSerialCache := nbgrpc.NewPeerSerialCache(context.Background(), s.CacheStore(), nbgrpc.DefaultPeerSerialCacheTTL)
-		fastPathFlag := nbgrpc.RunFastPathFlagRoutine(context.Background(), nbgrpc.DefaultFastPathFlagInterval, nbgrpc.DefaultFastPathRedisKey)
+		fastPathFlag := nbgrpc.RunFastPathFlagRoutine(context.Background(), s.CacheStore(), nbgrpc.DefaultFastPathFlagInterval, nbgrpc.DefaultFastPathFlagKey)
 		srv, err := nbgrpc.NewServer(s.Config, s.AccountManager(), s.SettingsManager(), s.JobManager(), s.SecretsManager(), s.Metrics(), s.AuthManager(), s.IntegratedValidator(), s.NetworkMapController(), s.OAuthConfigProvider(), peerSerialCache, fastPathFlag)
 		if err != nil {
 			log.Fatalf("failed to create management server: %v", err)

management/internals/shared/grpc/fast_path_flag.go

@@ -3,27 +3,24 @@ package grpc
 import (
 	"context"
 	"errors"
-	"fmt"
-	"os"
 	"strings"
 	"sync/atomic"
 	"time"
 
-	"github.com/redis/go-redis/v9"
+	"github.com/eko/gocache/lib/v4/cache"
+	"github.com/eko/gocache/lib/v4/store"
 	log "github.com/sirupsen/logrus"
 )
 
 const (
-	fastPathRedisURLEnv = "NB_PEER_SYNC_REDIS_ADDRESS"
-
 	// DefaultFastPathFlagInterval is the default poll interval for the Sync
 	// fast-path feature flag. Kept lower than the log-level overrider because
 	// operators will want the toggle to propagate quickly during rollout.
 	DefaultFastPathFlagInterval = 1 * time.Minute
 
-	// DefaultFastPathRedisKey is the Redis key polled by RunFastPathFlagRoutine
+	// DefaultFastPathFlagKey is the cache key polled by RunFastPathFlagRoutine
 	// when the caller does not provide an override.
-	DefaultFastPathRedisKey = "peerSyncFastPath"
+	DefaultFastPathFlagKey = "peerSyncFastPath"
 )
 
 // FastPathFlag exposes the current on/off state of the Sync fast path. The
@@ -34,7 +31,7 @@ type FastPathFlag struct {
 }
 
 // NewFastPathFlag returns a FastPathFlag whose state is set to the given
-// value. Callers that need the runtime Redis-backed toggle should use
+// value. Callers that need the runtime toggle should use
 // RunFastPathFlagRoutine instead; this constructor is meant for tests and
 // for consumers that want to force the flag on or off.
 func NewFastPathFlag(enabled bool) *FastPathFlag {
@@ -60,50 +57,46 @@ func (f *FastPathFlag) setEnabled(v bool) {
 	f.enabled.Store(v)
 }
 
-// RunFastPathFlagRoutine starts a background goroutine that polls Redis for
+// RunFastPathFlagRoutine starts a background goroutine that polls the shared
-// the Sync fast-path feature flag and updates the returned FastPathFlag
+// cache store for the Sync fast-path feature flag and updates the returned
-// accordingly. When NB_PEER_SYNC_REDIS_ADDRESS is not set the routine logs and
+// FastPathFlag accordingly. When cacheStore is nil the routine returns a
-// returns a handle that stays permanently disabled, so every Sync falls back
+// handle that stays permanently disabled, so every Sync falls back to the
-// to the full network map path.
+// full network map path.
-func RunFastPathFlagRoutine(ctx context.Context, interval time.Duration, redisKey string) *FastPathFlag {
+//
+// The shared store is Redis-backed when NB_CACHE_REDIS_ADDRESS is set (so the
+// flag is toggled cluster-wide by writing the key in Redis) and falls back to
+// an in-process gocache otherwise, which is enough for single-replica dev and
+// test setups.
+func RunFastPathFlagRoutine(ctx context.Context, cacheStore store.StoreInterface, interval time.Duration, flagKey string) *FastPathFlag {
 	flag := &FastPathFlag{}
 
-	redisEnvAddr := os.Getenv(fastPathRedisURLEnv)
+	if cacheStore == nil {
-	if redisEnvAddr == "" {
+		log.Infof("Shared cache store not provided. Sync fast path disabled")
-		log.Infof("Environment variable %s not set. Sync fast path disabled", fastPathRedisURLEnv)
 		return flag
 	}
 
-	client, err := getFastPathRedisStore(ctx, redisEnvAddr)
+	if flagKey == "" {
-	if err != nil {
+		flagKey = DefaultFastPathFlagKey
-		log.Errorf("Unable to connect to Redis at %v for Sync fast-path flag: %v", redisEnvAddr, err)
-		return flag
 	}
 
-	if redisKey == "" {
+	flagCache := cache.New[string](cacheStore)
-		redisKey = DefaultFastPathRedisKey
-	}
 
 	go func() {
 		ticker := time.NewTicker(interval)
-		defer func() {
+		defer ticker.Stop()
-			ticker.Stop()
-			if err := client.Close(); err != nil {
-				log.Debugf("close Sync fast-path redis client: %v", err)
-			}
-		}()
 
 		refresh := func() {
 			getCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
 			defer cancel()
 
-			value, err := client.Get(getCtx, redisKey).Result()
+			value, err := flagCache.Get(getCtx, flagKey)
-			if errors.Is(err, redis.Nil) {
-				flag.setEnabled(false)
-				return
-			}
 			if err != nil {
-				log.Errorf("Unable to get Sync fast-path flag from redis at %v: %v", redisEnvAddr, err)
+				var notFound *store.NotFound
+				if errors.As(err, &notFound) {
+					flag.setEnabled(false)
+					return
+				}
+				log.Debugf("Sync fast-path flag refresh: %v", err)
 				return
 			}
 			flag.setEnabled(parseFastPathFlag(value))
@@ -126,8 +119,7 @@ func RunFastPathFlagRoutine(ctx context.Context, interval time.Duration, redisKe
 }
 
 // parseFastPathFlag accepts "1" or "true" (any casing, surrounding whitespace
-// tolerated) as enabled and treats every other value as disabled. Missing
+// tolerated) as enabled and treats every other value as disabled.
-// keys surface as redis.Nil in the caller and also resolve to disabled.
 func parseFastPathFlag(value string) bool {
 	v := strings.TrimSpace(value)
 	if v == "1" {
@@ -135,21 +127,3 @@ func parseFastPathFlag(value string) bool {
 	}
 	return strings.EqualFold(v, "true")
 }
-
-func getFastPathRedisStore(ctx context.Context, redisEnvAddr string) (*redis.Client, error) {
-	options, err := redis.ParseURL(redisEnvAddr)
-	if err != nil {
-		return nil, fmt.Errorf("parse redis fast-path url: %w", err)
-	}
-
-	client := redis.NewClient(options)
-	subCtx, cancel := context.WithTimeout(ctx, 2*time.Second)
-	defer cancel()
-
-	if _, err := client.Ping(subCtx).Result(); err != nil {
-		return nil, err
-	}
-
-	log.WithContext(subCtx).Infof("using redis for Sync fast-path flag at %s", redisEnvAddr)
-	return client, nil
-}

management/internals/shared/grpc/fast_path_flag_test.go

@@ -5,10 +5,11 @@ import (
 	"testing"
 	"time"
 
-	"github.com/redis/go-redis/v9"
+	"github.com/eko/gocache/lib/v4/store"
+	gocache_store "github.com/eko/gocache/store/go_cache/v4"
+	gocache "github.com/patrickmn/go-cache"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-	testcontainersredis "github.com/testcontainers/testcontainers-go/modules/redis"
 )
 
 func TestParseFastPathFlag(t *testing.T) {
@@ -54,101 +55,75 @@ func TestFastPathFlag_SetEnabled(t *testing.T) {
 	assert.False(t, flag.Enabled(), "flag should report disabled after setEnabled(false)")
 }
 
-func TestFastPathRedisStore_InvalidURL(t *testing.T) {
+func TestNewFastPathFlag(t *testing.T) {
-	_, err := getFastPathRedisStore(context.Background(), "invalid-url")
+	assert.True(t, NewFastPathFlag(true).Enabled(), "NewFastPathFlag(true) should report enabled")
-	assert.Error(t, err, "Should fail with invalid URL")
+	assert.False(t, NewFastPathFlag(false).Enabled(), "NewFastPathFlag(false) should report disabled")
 }
 
-func TestFastPathRedisStore_UnreachableHost(t *testing.T) {
+func TestRunFastPathFlagRoutine_NilStoreStaysDisabled(t *testing.T) {
-	_, err := getFastPathRedisStore(context.Background(), "redis://127.0.0.1:59998")
-	assert.Error(t, err, "Should fail when Redis is unreachable")
-}
-
-func TestRunFastPathFlagRoutine_DisabledWithoutEnvVar(t *testing.T) {
-	t.Setenv(fastPathRedisURLEnv, "")
-
 	ctx, cancel := context.WithCancel(context.Background())
 	t.Cleanup(cancel)
 
-	flag := RunFastPathFlagRoutine(ctx, 100*time.Millisecond, "any-key")
+	flag := RunFastPathFlagRoutine(ctx, nil, 50*time.Millisecond, "peerSyncFastPath")
 	require.NotNil(t, flag, "RunFastPathFlagRoutine should always return a non-nil flag")
-	assert.False(t, flag.Enabled(), "flag should stay disabled when env var is unset")
+	assert.False(t, flag.Enabled(), "flag should stay disabled when no cache store is provided")
 
-	time.Sleep(250 * time.Millisecond)
+	time.Sleep(150 * time.Millisecond)
-	assert.False(t, flag.Enabled(), "flag should remain disabled even after wait when env var is unset")
+	assert.False(t, flag.Enabled(), "flag should remain disabled after wait when no cache store is provided")
 }
 
-func TestRunFastPathFlagRoutine_ReadsFlagFromRedis(t *testing.T) {
+func TestRunFastPathFlagRoutine_ReadsFlagFromStore(t *testing.T) {
-	redisURL, client := setupFastPathRedisContainer(t)
+	cacheStore := newFastPathTestStore(t)
-
-	t.Setenv(fastPathRedisURLEnv, redisURL)
-
 	ctx, cancel := context.WithCancel(context.Background())
 	t.Cleanup(cancel)
 
-	flag := RunFastPathFlagRoutine(ctx, 100*time.Millisecond, "peerSyncFastPath")
+	flag := RunFastPathFlagRoutine(ctx, cacheStore, 50*time.Millisecond, "peerSyncFastPath")
 	require.NotNil(t, flag)
-	assert.False(t, flag.Enabled(), "flag should start disabled with no key")
+	assert.False(t, flag.Enabled(), "flag should start disabled when the key is missing")
 
-	err := client.Set(ctx, "peerSyncFastPath", "1", 0).Err()
+	require.NoError(t, cacheStore.Set(ctx, "peerSyncFastPath", "1"), "seed flag=1 into shared store")
-	require.NoError(t, err, "set redis key must succeed")
+	assert.Eventually(t, flag.Enabled, 2*time.Second, 25*time.Millisecond, "flag should flip enabled after the key is set to 1")
-
-	assert.Eventually(t, flag.Enabled, 3*time.Second, 50*time.Millisecond, "flag should flip to enabled after Redis key is set to 1")
-
-	err = client.Set(ctx, "peerSyncFastPath", "0", 0).Err()
-	require.NoError(t, err, "reset redis key must succeed")
 
+	require.NoError(t, cacheStore.Set(ctx, "peerSyncFastPath", "0"), "override flag=0 into shared store")
 	assert.Eventually(t, func() bool {
 		return !flag.Enabled()
-	}, 3*time.Second, 50*time.Millisecond, "flag should flip back to disabled after Redis key is set to 0")
+	}, 2*time.Second, 25*time.Millisecond, "flag should flip disabled after the key is set to 0")
 
-	err = client.Del(ctx, "peerSyncFastPath").Err()
+	require.NoError(t, cacheStore.Delete(ctx, "peerSyncFastPath"), "remove flag key")
-	require.NoError(t, err, "delete redis key must succeed")
+	assert.Eventually(t, func() bool {
+		return !flag.Enabled()
+	}, 2*time.Second, 25*time.Millisecond, "flag should stay disabled after the key is deleted")
 
-	err = client.Set(ctx, "peerSyncFastPath", "true", 0).Err()
+	require.NoError(t, cacheStore.Set(ctx, "peerSyncFastPath", "true"), "enable via string true")
-	require.NoError(t, err)
+	assert.Eventually(t, flag.Enabled, 2*time.Second, 25*time.Millisecond, "flag should accept \"true\" as enabled")
-	assert.Eventually(t, flag.Enabled, 3*time.Second, 50*time.Millisecond, "flag should accept \"true\" as enabled")
 }
 
 func TestRunFastPathFlagRoutine_MissingKeyKeepsDisabled(t *testing.T) {
-	redisURL, _ := setupFastPathRedisContainer(t)
+	cacheStore := newFastPathTestStore(t)
-	t.Setenv(fastPathRedisURLEnv, redisURL)
-
 	ctx, cancel := context.WithCancel(context.Background())
 	t.Cleanup(cancel)
 
-	flag := RunFastPathFlagRoutine(ctx, 100*time.Millisecond, "peerSyncFastPathAbsent")
+	flag := RunFastPathFlagRoutine(ctx, cacheStore, 50*time.Millisecond, "peerSyncFastPathAbsent")
 	require.NotNil(t, flag)
 
-	time.Sleep(400 * time.Millisecond)
+	time.Sleep(200 * time.Millisecond)
-	assert.False(t, flag.Enabled(), "flag should stay disabled when the key is missing in Redis")
+	assert.False(t, flag.Enabled(), "flag should stay disabled when the key is missing from the store")
 }
 
-func setupFastPathRedisContainer(t *testing.T) (string, *redis.Client) {
+func TestRunFastPathFlagRoutine_DefaultKeyUsedWhenEmpty(t *testing.T) {
+	cacheStore := newFastPathTestStore(t)
+	ctx, cancel := context.WithCancel(context.Background())
+	t.Cleanup(cancel)
+
+	require.NoError(t, cacheStore.Set(ctx, DefaultFastPathFlagKey, "1"), "seed default key")
+
+	flag := RunFastPathFlagRoutine(ctx, cacheStore, 50*time.Millisecond, "")
+	require.NotNil(t, flag)
+
+	assert.Eventually(t, flag.Enabled, 2*time.Second, 25*time.Millisecond, "empty flagKey should fall back to DefaultFastPathFlagKey")
+}
+
+func newFastPathTestStore(t *testing.T) store.StoreInterface {
 	t.Helper()
-
+	return gocache_store.NewGoCache(gocache.New(5*time.Minute, 10*time.Minute))
-	ctx := context.Background()
-	redisContainer, err := testcontainersredis.Run(ctx, "redis:7")
-	require.NoError(t, err, "create redis test container")
-
-	t.Cleanup(func() {
-		if err := redisContainer.Terminate(ctx); err != nil {
-			t.Logf("failed to terminate redis container: %s", err)
-		}
-	})
-
-	redisURL, err := redisContainer.ConnectionString(ctx)
-	require.NoError(t, err)
-
-	options, err := redis.ParseURL(redisURL)
-	require.NoError(t, err)
-
-	client := redis.NewClient(options)
-	t.Cleanup(func() {
-		if err := client.Close(); err != nil {
-			t.Logf("failed to close redis client: %s", err)
-		}
-	})
-
-	return redisURL, client
 }