Knative Sequence KafkaChannel error

[Xiaojun Yang]

Hello,  there,

I tried to use KafakChannel for Sequence. Here is related yaml content. If I use InmemoryCHannel, all work out fine.  My broker is Kafak Broker. 

apiVersion: flows.knative.dev/v1

kind: Sequence

metadata:

  name: processors-sequence

spec:

  channelTemplate:

    apiVersion: messaging.knative.dev/v1beta1

    kind: KafkaChannel

    spec:

      numPartitions: 3

      replicationFactor: 1

    # apiVersion: messaging.knative.dev/v1

    # kind: InMemoryChannel

  steps:

    - ref:

        apiVersion: serving.knative.dev/v1

        kind: Service

        name: processor1

    - ref:

        apiVersion: serving.knative.dev/v1

        kind: Service

        name: processor2

    - ref:

        apiVersion: serving.knative.dev/v1

        kind: Service

        name: processor3

  reply:

    ref:

      kind: Broker

      apiVersion: eventing.knative.dev/v1

      name: kafka-poc-broker

errors:

➜  multitenants-4 kubectl get subscription.messaging.knative.dev -n tenant-c
NAME                                AGE   READY     REASON
processors-sequence-kn-sequence-0   15m   False     ReplyResolveFailed
processors-sequence-kn-sequence-1   15m   False     ReplyResolveFailed
processors-sequence-kn-sequence-2   15m   Unknown   SubscriptionNotMarkedReadyByChannel

➜  multitenants-4 kn subscription list -n tenant-c
NAME                                CHANNEL                                          SUBSCRIBER        REPLY
        DEAD LETTER SINK   READY     REASON
processors-sequence-kn-sequence-0   KafkaChannel:processors-sequence-kn-sequence-0   ksvc:processor1   kafkachannel:processors-sequence-kn-sequence-1                      False     ReplyResolveFailed : Failed to resolve spec.reply: address not set for Kind = KafkaChannel, Namespace = tenant-c, Name = processors-sequence-kn-sequence-1, APIVersion = messaging.knative.dev/v1beta1, Group = , Address =
processors-sequence-kn-sequence-1   KafkaChannel:processors-sequence-kn-sequence-1   ksvc:processor2   kafkachannel:processors-sequence-kn-sequence-2                      False     ReplyResolveFailed : Failed to resolve spec.reply: address not set for Kind = KafkaChannel, Namespace = tenant-c, Name = processors-sequence-kn-sequence-2, APIVersion = messaging.knative.dev/v1beta1, Group = , Address =
processors-sequence-kn-sequence-2   KafkaChannel:processors-sequence-kn-sequence-2   ksvc:processor3   broker:kafka-poc-broker

Could you tell me what's wrong? or any detailed reference doc for this?

Thanks a lot,

Xiaojun Yang