discovery service

2026-01-02 02:44:01 +01:00
parent 97ba7500dc
commit ea1c69f14a
47 changed files with 2799 additions and 701 deletions
--- a/api/pkg/discovery/watcher.go
+++ b/api/pkg/discovery/watcher.go
@@ -0,0 +1,126 @@
+package discovery
+
+import (
+	"encoding/json"
+	"errors"
+	"sync"
+	"time"
+
+	"github.com/nats-io/nats.go"
+	mb "github.com/tech/sendico/pkg/messaging/broker"
+	"github.com/tech/sendico/pkg/mlogger"
+	"go.uber.org/zap"
+)
+
+type RegistryWatcher struct {
+	logger   mlogger.Logger
+	registry *Registry
+	kv       *KVStore
+	watcher  nats.KeyWatcher
+
+	stopOnce sync.Once
+}
+
+func NewRegistryWatcher(logger mlogger.Logger, msgBroker mb.Broker, registry *Registry) (*RegistryWatcher, error) {
+	if msgBroker == nil {
+		return nil, errors.New("discovery watcher: broker is nil")
+	}
+	if registry == nil {
+		registry = NewRegistry()
+	}
+	if logger != nil {
+		logger = logger.Named("discovery_watcher")
+	}
+	provider, ok := msgBroker.(jetStreamProvider)
+	if !ok {
+		return nil, errors.New("discovery watcher: jetstream not available")
+	}
+	js := provider.JetStream()
+	if js == nil {
+		return nil, errors.New("discovery watcher: jetstream not configured")
+	}
+	store, err := NewKVStore(logger, js, "")
+	if err != nil {
+		return nil, err
+	}
+
+	return &RegistryWatcher{
+		logger:   logger,
+		registry: registry,
+		kv:       store,
+	}, nil
+}
+
+func (w *RegistryWatcher) Start() error {
+	if w == nil || w.kv == nil {
+		return errors.New("discovery watcher: not configured")
+	}
+	watcher, err := w.kv.WatchAll()
+	if err != nil {
+		return err
+	}
+	w.watcher = watcher
+	if w.logger != nil {
+		w.logger.Info("Discovery registry watcher started", zap.String("bucket", w.kv.Bucket()))
+	}
+	go w.consume(watcher)
+	return nil
+}
+
+func (w *RegistryWatcher) Stop() {
+	if w == nil {
+		return
+	}
+	w.stopOnce.Do(func() {
+		if w.watcher != nil {
+			_ = w.watcher.Stop()
+		}
+		if w.logger != nil {
+			w.logger.Info("Discovery registry watcher stopped")
+		}
+	})
+}
+
+func (w *RegistryWatcher) Registry() *Registry {
+	if w == nil {
+		return nil
+	}
+	return w.registry
+}
+
+func (w *RegistryWatcher) consume(watcher nats.KeyWatcher) {
+	if w == nil || watcher == nil {
+		return
+	}
+	for entry := range watcher.Updates() {
+		if entry == nil {
+			continue
+		}
+		switch entry.Operation() {
+		case nats.KeyValueDelete, nats.KeyValuePurge:
+			key := registryKeyFromKVKey(entry.Key())
+			if key != "" {
+				if w.registry.Delete(key) && w.logger != nil {
+					w.logger.Info("Discovery registry entry removed", zap.String("key", key))
+				}
+			}
+			continue
+		case nats.KeyValuePut:
+		default:
+			continue
+		}
+
+		var payload RegistryEntry
+		if err := json.Unmarshal(entry.Value(), &payload); err != nil {
+			if w.logger != nil {
+				w.logger.Warn("Failed to decode discovery KV entry", zap.String("key", entry.Key()), zap.Error(err))
+			}
+			continue
+		}
+		result := w.registry.UpsertEntry(payload, time.Now())
+		if w.logger != nil && (result.IsNew || result.BecameHealthy) {
+			fields := append(entryFields(result.Entry), zap.Bool("is_new", result.IsNew), zap.Bool("became_healthy", result.BecameHealthy))
+			w.logger.Info("Discovery registry entry updated from KV", fields...)
+		}
+	}
+}