grpc-kafka feature (baseline)

[jfallows]

Baseline

• binding-grpc assumes http network mapping to grpc application streams
  • follow grpc http2 wire protocol definition Support gRPC proxying #171
• binding-grpc-kafka maps grpc streams to kafka streams
  • grpc-kafka mapping Support gRPC Kafka mapping #184
    • route grpc service name and method name to kafka topic with reply-to
    • use hash of grpc request to generate idempotency-key if omitted from metadata
    • use grpc idempotency-key as injected kafka header zilla:correlation-id
  • server streaming Support gRPC Kafka server streaming #186
    • unreliable server streaming, similar to sse-kafka without last-event-id
    • reliable server streaming, similar to sse-kafka with last-event-id
• binding-kafka-grpc maps kafka streams to grpc streams
  • kafka-grpc mapping Support Kafka gRPC mapping #185
    • route grpc service name and method name to kafka topic with reply-to
    • correlated request-response from kafka to grpc server
• zilla-examples
  • grpc.echo example zilla-examples#34
  • grpc.kafka.echo example zilla-examples#35
  • grpc.proxy example zilla-examples#32
  • grpc.kafka.proxy example zilla-examples#33
  • grpc.kafka.fanout example zilla-examples#36