Add push server component template

pushserver/consumers/roomserver.go

@@ -0,0 +1,82 @@
+package consumers
+
+import (
+	"encoding/json"
+
+	"github.com/Shopify/sarama"
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/pushserver/api"
+	"github.com/matrix-org/dendrite/pushserver/storage"
+	rsapi "github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/dendrite/setup/process"
+	log "github.com/sirupsen/logrus"
+)
+
+type OutputRoomEventConsumer struct {
+	cfg        *config.PushServer
+	psAPI      api.PushserverInternalAPI
+	rsConsumer *internal.ContinualConsumer
+	db         storage.Database
+}
+
+func NewOutputRoomEventConsumer(
+	process *process.ProcessContext,
+	cfg *config.PushServer,
+	kafkaConsumer sarama.Consumer,
+	store storage.Database,
+	psAPI api.PushserverInternalAPI,
+) *OutputRoomEventConsumer {
+	consumer := internal.ContinualConsumer{
+		Process:        process,
+		ComponentName:  "pushserver/roomserver",
+		Topic:          string(cfg.Matrix.Kafka.TopicFor(config.TopicOutputRoomEvent)),
+		Consumer:       kafkaConsumer,
+		PartitionStore: store,
+	}
+	s := &OutputRoomEventConsumer{
+		cfg:        cfg,
+		rsConsumer: &consumer,
+		db:         store,
+		psAPI:      psAPI,
+	}
+	consumer.ProcessMessage = s.onMessage
+	return s
+}
+
+func (s *OutputRoomEventConsumer) Start() error {
+	return s.rsConsumer.Start()
+}
+
+func (s *OutputRoomEventConsumer) onMessage(msg *sarama.ConsumerMessage) error {
+	var output rsapi.OutputEvent
+	if err := json.Unmarshal(msg.Value, &output); err != nil {
+		log.WithError(err).Errorf("roomserver output log: message parse failure")
+		return nil
+	}
+
+	switch output.Type {
+	case rsapi.OutputTypeNewRoomEvent:
+		ev := output.NewRoomEvent.Event
+		if err := s.processMessage(*output.NewRoomEvent); err != nil {
+			// panic rather than continue with an inconsistent database
+			log.WithFields(log.Fields{
+				"event_id":   ev.EventID(),
+				"event":      string(ev.JSON()),
+				log.ErrorKey: err,
+			}).Panicf("roomserver output log: write room event failure")
+			return err
+		}
+
+	default:
+		// Ignore old events, peeks, so on.
+	}
+
+	return nil
+}
+
+func (s *OutputRoomEventConsumer) processMessage(ore rsapi.OutputNewRoomEvent) error {
+	// TODO: New events from the roomserver will be passed here.
+
+	return nil
+}