kafka-grpc Binding

Zilla runtime kafka-grpc binding.

kafka_grpc_proxy:
  type: kafka-grpc
  kind: remote_server
  entry: kafka_cache_client
  options:
    acks: leader_only
    idempotency:
      metadata: idempotency-key
    correlation:
      headers:
        service: zilla:service
        method: zilla:method
        correlation-id: zilla:correlation-id
        reply-to: zilla:reply-to
  routes:
    - when:
        - topic: requests
          reply-to: responses
          method: example.EchoService/*
      exit: grpc
      with:
        scheme: http
        authority: localhost:7151

Summary

The remote_server kind kafka-grpc binding adapts kafka topic streams to grpc request-response streams.

The grpc request message is received from a requests topic, with a zilla:correlation-id header, initiating a grpc service method invocation. When the grpc response received, a response message is produced to the responses topic, with the same zilla:correlation-id header to correlate the response.

Note that grpc requests and responses can be unary or streaming.

Configuration

Properties

• kind*
• options
  • options.acks
  • options.idempotency
    • idempotency.metadata
  • options.correlation
    • correlation.headers
    • headers.service
    • headers.method
    • headers.correlation-id
    • headers.reply-to
• routes
• routes[].guarded
• routes[].when
  • when[].topic
  • when[].reply-to
  • when[].method
• routes[].exit*
• routes[].with
  • with.scheme
  • with.authority

* required

kind*

enum [ "remote_server" ]

Behave as an kafka-grpc remote_server.

kind: remote_server

options

object

kafka-grpc-specific options for adapting kafka topic streams to grpc request-response streams.

options:
  acks: leader_only
  idempotency:
    metadata: idempotency-key
  correlation:
    headers:
      service: zilla:service
      method: zilla:method
      correlation-id: zilla:correlation-id
      reply-to: zilla:reply-to

options.acks

enum [ "none", "leader_only", "in_sync_replicas" ]

The kafka acknowledgment mode.

options.idempotency

object

Metadata header used to specify the idempotency key when adapting kafka topic streams to grpc request-response streams.

idempotency.metadata

string | Default: "idempotency-key".

The grpc metadata header name for idempotency key.

options.correlation

object

Kafka request message headers injected when adapting kafka topic streams to grpc request-response streams.

correlation.headers

object

Kafka request message correlation header names used when adapting kafka topic streams to grpc request-response streams.

headers.service

string | Default: "zilla:service"

Kafka header name for grpc service.

headers.method

string | Default: "zilla:method"

Kafka header name for grpc method.

headers.correlation-id

string | Default: "zilla:correlation-id"

Kafka header name for request-response correlation identifier.

headers.reply-to

string | Default: "zilla:reply-to"

Kafka header name for reply-to topic.

routes

array of object

Conditional kafka-grpc-specific routes for adapting kafka topic streams to grpc request-response streams.

routes:
  - guarded:
      test:
        - echo:messages
    when:
      - topic: requests
        reply-to: responses
        method: example.EchoService/*
    exit: grpc
    with:
      scheme: http
      authority: localhost:7151

routes[].guarded

object as named map of string:string array

Roles required by named guard.

routes:
  - guarded:
      test:
        - echo:messages

routes[].when

array of object

List of conditions (any match) to match this route when adapting kafka topic streams to grpc request-response streams.
Read more: When a route matches

routes:
  - when:
      - topic: requests
        reply-to: responses
        method: example.EchoService/*

when[].topic

string

The name of a Kafka topic for requests.

when[].reply-to

string

The name of the Kafka topic for correlated responses.

when[].method

string

Pattern matching the fully qualified name of a grpc service method, in the format <service>/<method> allowing wildcard * for the method to indicate any method.

routes[].exit*

string

Default exit binding when no conditional routes are viable.

routes:
  - when:
    ...
    exit: kafka_cache_client

routes[].with

object

Kafka parameters for matched route when adapting grpc request-response streams to kafka topic fetch streams.

with:
  scheme: http
  authority: localhost:7151

with.scheme

string

The grpc request scheme.

with.authority

string

The grpc request authority.

---

* required