Build a micro-services API

This talk introduces Mu, a new FP library for building micro-services APIs. Mu offers code annotations for defining RPC or REST APIs, message types, and serialization formats, thus removing the dependency on protocol-specific declarations and enabling seamless changes between different implementations.

Transcript

1. © Vizualus. All Rights Reserved. 1 Build a micro- services API @oli_kitty Oli Makhasoeva, Solutions Architect, 47 Degrees
2. @message 2 import higherkindness.mu.rpc.protocol._ @message case class SumRequest(a: Int, b: Int) @message case class SumResponse(sum: Int)
3. 3 @service() trait MathService[F[_]] { def sum(req: SumRequest): F[SumResponse] } @service
4. 4 Macros val methodDescriptor: DefDef = q""" def $methodDescriptorName(implicit ReqM: …MethodDescriptor.Marshaller[$reqType], RespM: …MethodDescriptor.Marshaller[$respType] ): …MethodDescriptor[$reqType, $respType] = { …MethodDescriptor.newBuilder(ReqM, RespM) .setType($streamingMethodType) .setFullMethodName( …MethodDescriptor .generateFullMethodName( ${lit(serviceName)}, ${lit(methodName)} )) .build()} """
5. 5 @service(Protobuf) trait MathService[F[_]] { def sum(req: SumRequest): F[SumResponse] } @service. Protobuf
6. 6 @service(Avro) trait MathService[F[_]] { def sum(req: SumRequest): F[SumResponse] } @service. Avro
7. 7 @service(Protobuf) trait MathService[F[_]] { @http def sum(req: SumRequest): F[SumResponse] } @http
8. 8 @service(???) trait MathService[F[_]] { def sum(req: SumRequest): F[SumResponse] } @service. Your protocol
9. 9 Skeuomorph {JSON} ??? github.com/higherkindness/skeuomorph
10. 10 def transformAvro[A]: Trans[AvroF, MuF, A] = Trans { case AvroF.TBoolean() => TBoolean() case AvroF.TInt() => TInt() case AvroF.TDouble() => TDouble() case AvroF.TString() => TString() case AvroF.TArray(item) => TList(item) case AvroF.TRecord(name, _, _, _, fields) => TProduct(name, fields.map(f => Field(f.name, f.tpe))) … } Recursion schemes github.com/higherkindness/skeuomorph
11. 11 @message case class SumRequest(a: Int, b: Int) @message case class SumResponse(sum: Int) @service(Protobuf) trait MathService[F[_]] { def sum(sumRequest: SumRequest): F[SumResponse] } Service implementation
12. 12 @service(Protobuf) trait MathService[F[_]] { def sum(req: SumRequest): F[SumResponse] } Server side class MathServiceHandler[F[_]](implicit M: Applicative[F]) extends MathService[F] { override def sum(req: SumRequest): F[SumResponse] = SumResponse(req.a + req.b).pure[F] }
13. 13 def main(args: Array[String]): Unit = { val grpcConfig: IO[List[GrpcConfig]] = List( MathService.bindService[IO].map(AddService) ).sequence } Server App
14. 14 def main(args: Array[String]): Unit = { val grpcConfig: IO[List[GrpcConfig]] = ??? val runServer = for { c <- grpcConfig server <- BuildServerFromConfig[IO]( "rpc.server.port", c ) _ <- GrpcServer.server[IO](server) } yield () } Server App
15. 15 def main(args: Array[String]): Unit = { val grpcConfig: IO[List[GrpcConfig]] = ??? val runServer = for { c <- grpcConfig server <- BuildServerFromConfig[IO](???) _ <- GrpcServer.server[IO](server) } yield () runServer.unsafeRunSync } Server App
16. 16 Client Side val chFor: ChannelFor = ConfigForAddress[IO](“rpc.client.host", “rpc.client.port”) .unsafeRunSync()
17. 17 Client Side val chFor: ChannelFor = ConfigForAddress[IO](“rpc.client.host", “rpc.client.port”) .unsafeRunSync() val grpcClient: Resource[IO, MathService[IO]] = MathService.client[IO](chFor)
18. 18 Client Side val chFor: ChannelFor = ConfigForAddress[IO](“rpc.client.host", “rpc.client.port”) .unsafeRunSync() val grpcClient: Resource[IO, MathService[IO]] = MathService.client[IO](chFor) val ioClient: SumClientImpl[IO] = new SumClientImpl[IO](grpcClient)
19. 19 object SumApp { def main(args: Array[String]): Unit = { sum[IO].unsafeRunSync() } def sum[F[_]](implicit client: SumClient[F]): F[Int] = client.sum(SumRequest(1, 2)) } Client App
20. 20 def hi(req: Observable[HiRequest] ): Observable[HiResponse] MONIX def hi(req: Stream[F, HiRequest] ): Stream[F, HiResponse] FS2 Streaming rpc hi (stream HiRequest) returns (stream HiResponse); fs2.io monix.io
21. 21 addSbtPlugin("io.higherkindness" % "sbt-mu-idlgen" % “0.17.1") idlType := "avro" srcGenSerializationType := "Avro" sourceGenerators in Compile += (srcGen in Compile).taskValue IDL generation
22. 22 Flexibility OSS Extensibility Rapid API development Modularity
23. © Vizualus. All Rights Reserved. 23 Thank you! Oli Makhasoeva, Solutions Architect, 47 Degrees @oli_kitty scala.love scalalaz.ru FUN[C] @fun_c_ higherkindness.io/mu 47deg.com
24. © Vizualus. All Rights Reserved. 24