[FSSDK-9631] feat: add datafile syncer to synchronize datafile across agent nodes for webhook API (#405)

* feat: add redis syncer for webhook

* Modify syncer

* fix bug

* add various fix

* refactor code

* refactor code

* add unit test

* improve logging

* add unit test for pubsub

* add unit test

* add unit test

* add unit test

* add unit test

* refactor code

* cleanup

* update config

* add review changes

* update config doc

Author: pulak-opti

cmd/optimizely/main.go

@@ -33,6 +33,7 @@ import (
 	"github.com/spf13/viper"
 
 	"github.com/optimizely/agent/config"
+	"github.com/optimizely/agent/pkg/handlers"
 	"github.com/optimizely/agent/pkg/metrics"
 	"github.com/optimizely/agent/pkg/optimizely"
 	"github.com/optimizely/agent/pkg/routers"
@@ -266,7 +267,10 @@ func main() {
 	sdkMetricsRegistry := optimizely.NewRegistry(agentMetricsRegistry)
 
 	ctx, cancel := context.WithCancel(context.Background()) // Create default service context
-	sg := server.NewGroup(ctx, conf.Server)                 // Create a new server group to manage the individual http listeners
+	defer cancel()
+	ctx = context.WithValue(ctx, handlers.LoggerKey, &log.Logger)
+
+	sg := server.NewGroup(ctx, conf.Server) // Create a new server group to manage the individual http listeners
 	optlyCache := optimizely.NewCache(ctx, *conf, sdkMetricsRegistry)
 	optlyCache.Init(conf.SDKKeys)
 
@@ -286,7 +290,7 @@ func main() {
 
 	log.Info().Str("version", conf.Version).Msg("Starting services.")
 	sg.GoListenAndServe("api", conf.API.Port, apiRouter)
-	sg.GoListenAndServe("webhook", conf.Webhook.Port, routers.NewWebhookRouter(optlyCache, conf.Webhook))
+	sg.GoListenAndServe("webhook", conf.Webhook.Port, routers.NewWebhookRouter(ctx, optlyCache, *conf))
 	sg.GoListenAndServe("admin", conf.Admin.Port, adminRouter) // Admin should be added last.
 
 	// wait for server group to shutdown

config.yaml

@@ -244,16 +244,20 @@ runtime:
     ## (For n>1 the details of sampling may change.)
     mutexProfileFraction: 0
 
-## synchronization should be enabled when multiple replicas of agent is deployed
-## if notification synchronization is enabled, then the active notification event-stream API
-## will get the notifications from multiple replicas
+## synchronization should be enabled when features for multiple nodes like notification streaming are deployed
 synchronization:
     pubsub:
         redis:
             host: "redis.demo.svc:6379"
             password: ""
             database: 0
-            channel: "optimizely-sync"
+    ## if notification synchronization is enabled, then the active notification event-stream API
+    ## will get the notifications from available replicas
     notification:
         enable: false
         default: "redis"
+    ## if datafile synchronization is enabled, then for each webhook API call
+    ## the datafile will be sent to all available replicas to achieve better eventual consistency
+    datafile:
+        enable: false
+        default: "redis"

config/config.go

@@ -135,7 +135,7 @@ func NewDefaultConfig() *AgentConfig {
 					"channel":  "optimizely-notifications",
 				},
 			},
-			Notification: NotificationConfig{
+			Notification: FeatureSyncConfig{
 				Enable:  false,
 				Default: "redis",
 			},
@@ -167,11 +167,12 @@ type AgentConfig struct {
 // SyncConfig contains Synchronization configuration for the multiple Agent nodes
 type SyncConfig struct {
 	Pubsub       map[string]interface{} `json:"pubsub"`
-	Notification NotificationConfig     `json:"notification"`
+	Notification FeatureSyncConfig      `json:"notification"`
+	Datafile     FeatureSyncConfig      `json:"datafile"`
 }
 
-// NotificationConfig contains Notification Synchronization configuration for the multiple Agent nodes
-type NotificationConfig struct {
+// FeatureSyncConfig contains Notification Synchronization configuration for the multiple Agent nodes
+type FeatureSyncConfig struct {
 	Enable  bool   `json:"enable"`
 	Default string `json:"default"`
 }

pkg/handlers/notification.go

@@ -25,7 +25,6 @@ import (
 	"net/http"
 	"strings"
 
-	"github.com/go-redis/redis/v8"
 	"github.com/optimizely/agent/config"
 	"github.com/optimizely/agent/pkg/middleware"
 	"github.com/optimizely/agent/pkg/syncer"
@@ -212,26 +211,22 @@ func DefaultNotificationReceiver(ctx context.Context) (<-chan syncer.Event, erro
 	return messageChan, nil
 }
 
-func RedisNotificationReceiver(conf config.SyncConfig) NotificationReceiverFunc {
+func SyncedNotificationReceiver(conf config.SyncConfig) NotificationReceiverFunc {
 	return func(ctx context.Context) (<-chan syncer.Event, error) {
 		sdkKey, ok := ctx.Value(SDKKey).(string)
 		if !ok || sdkKey == "" {
 			return nil, errors.New("sdk key not found")
 		}
 
-		redisSyncer, err := syncer.NewRedisSyncer(&zerolog.Logger{}, conf, sdkKey)
+		ncSyncer, err := syncer.NewSyncedNotificationCenter(ctx, sdkKey, conf)
 		if err != nil {
 			return nil, err
 		}
 
-		client := redis.NewClient(&redis.Options{
-			Addr:     redisSyncer.Host,
-			Password: redisSyncer.Password,
-			DB:       redisSyncer.Database,
-		})
-
-		// Subscribe to a Redis channel
-		pubsub := client.Subscribe(ctx, syncer.GetChannelForSDKKey(redisSyncer.Channel, sdkKey))
+		eventCh, err := ncSyncer.Subscribe(ctx, syncer.GetChannelForSDKKey(syncer.PubSubDefaultChan, sdkKey))
+		if err != nil {
+			return nil, err
+		}
 
 		dataChan := make(chan syncer.Event)
 
@@ -244,19 +239,12 @@ func RedisNotificationReceiver(conf config.SyncConfig) NotificationReceiverFunc
 			for {
 				select {
 				case <-ctx.Done():
-					client.Close()
-					pubsub.Close()
+					close(dataChan)
 					logger.Debug().Msg("context canceled, redis notification receiver is closed")
 					return
-				default:
-					msg, err := pubsub.ReceiveMessage(ctx)
-					if err != nil {
-						logger.Err(err).Msg("failed to receive message from redis")
-						continue
-					}
-
+				case msg := <-eventCh:
 					var event syncer.Event
-					if err := json.Unmarshal([]byte(msg.Payload), &event); err != nil {
+					if err := json.Unmarshal([]byte(msg), &event); err != nil {
 						logger.Err(err).Msg("failed to unmarshal redis message")
 						continue
 					}

pkg/handlers/notification_test.go

@@ -216,7 +216,7 @@ func (suite *NotificationTestSuite) TestTrackAndProjectConfigWithSynchronization
 				"database": 0,
 			},
 		},
-		Notification: config.NotificationConfig{
+		Notification: config.FeatureSyncConfig{
 			Enable:  true,
 			Default: "redis",
 		},
@@ -370,7 +370,7 @@ func TestRedisNotificationReceiver(t *testing.T) {
 				"database": 0,
 			},
 		},
-		Notification: config.NotificationConfig{
+		Notification: config.FeatureSyncConfig{
 			Enable:  true,
 			Default: "redis",
 		},
@@ -407,7 +407,7 @@ func TestRedisNotificationReceiver(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got := RedisNotificationReceiver(tt.args.conf)
+			got := SyncedNotificationReceiver(tt.args.conf)
 			if reflect.TypeOf(got) != reflect.TypeOf(tt.want) {
 				t.Errorf("RedisNotificationReceiver() = %v, want %v", got, tt.want)
 			}

pkg/handlers/webhook.go

@@ -18,21 +18,25 @@
 package handlers
 
 import (
+	"context"
 	"crypto/hmac"
 	"crypto/sha1"
 	"crypto/subtle"
 	"encoding/hex"
 	"encoding/json"
+	"fmt"
 	"io"
 	"net/http"
 	"strconv"
 
 	"github.com/optimizely/agent/config"
 
 	"github.com/go-chi/render"
+	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
 
 	"github.com/optimizely/agent/pkg/optimizely"
+	"github.com/optimizely/agent/pkg/syncer"
 )
 
 const signatureHeader = "X-Hub-Signature"
@@ -56,15 +60,19 @@ type OptlyMessage struct {
 
 // OptlyWebhookHandler handles incoming messages from Optimizely
 type OptlyWebhookHandler struct {
-	optlyCache optimizely.Cache
-	ProjectMap map[int64]config.WebhookProject
+	optlyCache   optimizely.Cache
+	ProjectMap   map[int64]config.WebhookProject
+	configSyncer syncer.Syncer
+	syncEnabled  bool
 }
 
 // NewWebhookHandler returns a new instance of OptlyWebhookHandler
-func NewWebhookHandler(optlyCache optimizely.Cache, projectMap map[int64]config.WebhookProject) *OptlyWebhookHandler {
+func NewWebhookHandler(optlyCache optimizely.Cache, projectMap map[int64]config.WebhookProject, configSyncer syncer.Syncer) *OptlyWebhookHandler {
 	return &OptlyWebhookHandler{
-		optlyCache: optlyCache,
-		ProjectMap: projectMap,
+		optlyCache:   optlyCache,
+		ProjectMap:   projectMap,
+		syncEnabled:  configSyncer != nil,
+		configSyncer: configSyncer,
 	}
 }
 
@@ -140,7 +148,47 @@ func (h *OptlyWebhookHandler) HandleWebhook(w http.ResponseWriter, r *http.Reque
 
 	// Iterate through all SDK keys and update config
 	for _, sdkKey := range webhookConfig.SDKKeys {
-		h.optlyCache.UpdateConfigs(sdkKey)
+		if h.syncEnabled {
+			if err := h.configSyncer.Sync(r.Context(), syncer.GetDatafileSyncChannel(), sdkKey); err != nil {
+				errMsg := fmt.Sprintf("datafile synced failed. reason: %s", err.Error())
+				log.Error().Msg(errMsg)
+				h.optlyCache.UpdateConfigs(sdkKey)
+			}
+		} else {
+			h.optlyCache.UpdateConfigs(sdkKey)
+		}
 	}
 	w.WriteHeader(http.StatusNoContent)
 }
+
+func (h *OptlyWebhookHandler) StartSyncer(ctx context.Context) error {
+	logger, ok := ctx.Value(LoggerKey).(*zerolog.Logger)
+	if !ok {
+		logger = &log.Logger
+	}
+
+	if !h.syncEnabled {
+		logger.Debug().Msg("datafile syncer is not enabled")
+		return nil
+	}
+
+	dataCh, err := h.configSyncer.Subscribe(ctx, syncer.GetDatafileSyncChannel())
+	if err != nil {
+		return err
+	}
+
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				logger.Debug().Msg("context canceled, syncer is stopped")
+				return
+			case key := <-dataCh:
+				h.optlyCache.UpdateConfigs(key)
+				logger.Info().Msgf("datafile synced successfully for sdkKey: %s", key)
+			}
+		}
+	}()
+	logger.Debug().Msg("datafile syncer is started")
+	return nil
+}

pkg/handlers/webhook_test.go

@@ -19,6 +19,7 @@ package handlers
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
@@ -46,6 +47,28 @@ func NewCache() *TestCache {
 	}
 }
 
+type TestDFSyncer struct {
+	syncCalled      bool
+	subscribeCalled bool
+}
+
+func NewTestDFSyncer() *TestDFSyncer {
+	return &TestDFSyncer{
+		syncCalled:      false,
+		subscribeCalled: false,
+	}
+}
+
+func (t *TestDFSyncer) Sync(_ context.Context, _ string, _ string) error {
+	t.syncCalled = true
+	return nil
+}
+
+func (t *TestDFSyncer) Subscribe(_ context.Context, _ string) (chan string, error) {
+	t.subscribeCalled = true
+	return make(chan string), nil
+}
+
 // GetClient returns a default OptlyClient for testing
 func (tc *TestCache) GetClient(sdkKey string) (*optimizely.OptlyClient, error) {
 	return &optimizely.OptlyClient{
@@ -111,7 +134,7 @@ func TestHandleWebhookValidMessageInvalidSignature(t *testing.T) {
 			Secret:  "I am secret",
 		},
 	}
-	optlyHandler := NewWebhookHandler(nil, testWebhookConfigs)
+	optlyHandler := NewWebhookHandler(nil, testWebhookConfigs, nil)
 	webhookMsg := OptlyMessage{
 		ProjectID: 42,
 		Timestamp: 42424242,
@@ -146,7 +169,7 @@ func TestHandleWebhookSkippedCheckInvalidSignature(t *testing.T) {
 			SkipSignatureCheck: true,
 		},
 	}
-	optlyHandler := NewWebhookHandler(testCache, testWebhookConfigs)
+	optlyHandler := NewWebhookHandler(testCache, testWebhookConfigs, nil)
 	webhookMsg := OptlyMessage{
 		ProjectID: 42,
 		Timestamp: 42424242,
@@ -181,7 +204,7 @@ func TestHandleWebhookValidMessage(t *testing.T) {
 			Secret:  "I am secret",
 		},
 	}
-	optlyHandler := NewWebhookHandler(testCache, testWebhookConfigs)
+	optlyHandler := NewWebhookHandler(testCache, testWebhookConfigs, nil)
 	webhookMsg := OptlyMessage{
 		ProjectID: 42,
 		Timestamp: 42424242,
@@ -208,3 +231,55 @@ func TestHandleWebhookValidMessage(t *testing.T) {
 	assert.Equal(t, http.StatusNoContent, rec.Code)
 	assert.Equal(t, true, testCache.updateConfigsCalled)
 }
+
+func TestHandleWebhookWithDatafileSyncer(t *testing.T) {
+	var testWebhookConfigs = map[int64]config.WebhookProject{
+		42: {
+			SDKKeys: []string{"myDatafile"},
+			Secret:  "I am secret",
+		},
+	}
+	syncer := NewTestDFSyncer()
+
+	optlyHandler := NewWebhookHandler(nil, testWebhookConfigs, syncer)
+	webhookMsg := OptlyMessage{
+		ProjectID: 42,
+		Timestamp: 42424242,
+		Event:     "project.datafile_updated",
+		Data: DatafileUpdateData{
+			Revision:    101,
+			OriginURL:   "origin.optimizely.com/datafiles/myDatafile",
+			CDNUrl:      "cdn.optimizely.com/datafiles/myDatafile",
+			Environment: "Production",
+		},
+	}
+
+	validWebhookMessage, _ := json.Marshal(webhookMsg)
+
+	req := httptest.NewRequest("POST", "/webhooks/optimizely", bytes.NewBuffer(validWebhookMessage))
+
+	// This sha1 has been computed from the Optimizely application
+	req.Header.Set(signatureHeader, "sha1=e0199de63fb7192634f52136d4ceb7dc6f191da3")
+
+	rec := httptest.NewRecorder()
+	handler := http.HandlerFunc(optlyHandler.HandleWebhook)
+	handler.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusNoContent, rec.Code)
+	assert.Equal(t, true, syncer.syncCalled)
+}
+
+func TestWebhookStartSyncer(t *testing.T) {
+	var testWebhookConfigs = map[int64]config.WebhookProject{
+		42: {
+			SDKKeys: []string{"myDatafile"},
+			Secret:  "I am secret",
+		},
+	}
+	syncer := NewTestDFSyncer()
+
+	optlyHandler := NewWebhookHandler(nil, testWebhookConfigs, syncer)
+	err := optlyHandler.StartSyncer(context.Background())
+	assert.NoError(t, err)
+	assert.Equal(t, true, syncer.subscribeCalled)
+}