feat: Add grpc-server module with PureConfig integration (#104)

* feat: Add grpc-server module with PureConfig integration

* fix: Disable WartRemover NonUnitStatements (false positive)

* refactor: Rename method arg

Author: jakubjanecek

build.sbt

@@ -27,6 +27,8 @@ lazy val root = project
     example,
     flyway,
     flywayPureConfig,
+    grpcServer,
+    grpcServerPureConfig,
     http4sClientBlaze,
     http4sClientBlazePureConfig,
     http4sClientMonixCatnap,
@@ -168,6 +170,27 @@ lazy val flywayPureConfig = project
     libraryDependencies += Dependencies.pureConfig
   )
 
+lazy val grpcServer = project
+  .in(file("grpc-server"))
+  .settings(commonSettings)
+  .settings(
+    name := "sst-grpc-server",
+    libraryDependencies ++= Seq(
+      Dependencies.grpcNettyShaded,
+      Dependencies.grpcProtobuf,
+      Dependencies.grpcStub
+    )
+  )
+
+lazy val grpcServerPureConfig = project
+  .in(file("grpc-server-pureconfig"))
+  .dependsOn(grpcServer)
+  .settings(commonSettings)
+  .settings(
+    name := "sst-grpc-server-pureconfig",
+    libraryDependencies += Dependencies.pureConfig
+  )
+
 lazy val http4sClientBlaze = project
   .in(file("http4s-client-blaze"))
   .settings(commonSettings)

grpc-server-pureconfig/src/main/scala/com/avast/sst/grpc/server/pureconfig/ConfigReaders.scala

@@ -0,0 +1,11 @@
+package com.avast.sst.grpc.server.pureconfig
+
+import com.avast.sst.grpc.server.GrpcServerConfig
+import pureconfig.ConfigReader
+import pureconfig.generic.semiauto.deriveReader
+
+trait ConfigReaders {
+
+  implicit val grpcServerGrpcServerConfigReader: ConfigReader[GrpcServerConfig] = deriveReader
+
+}

grpc-server-pureconfig/src/main/scala/com/avast/sst/grpc/server/pureconfig/implicits.scala

@@ -0,0 +1,20 @@
+package com.avast.sst.grpc.server.pureconfig
+
+import pureconfig.ConfigFieldMapping
+import pureconfig.generic.ProductHint
+
+/** Contains [[pureconfig.ConfigReader]] instances with default "kebab-case" naming convention. */
+object implicits extends ConfigReaders {
+
+  /** Contains [[pureconfig.ConfigReader]] instances with "kebab-case" naming convention.
+    *
+    * This is alias for the default `implicits._` import.
+    */
+  object KebabCase extends ConfigReaders
+
+  /** Contains [[pureconfig.ConfigReader]] instances with "camelCase" naming convention. */
+  object CamelCase extends ConfigReaders {
+    implicit def hint[T]: ProductHint[T] = ProductHint(ConfigFieldMapping(pureconfig.CamelCase, pureconfig.CamelCase))
+  }
+
+}

grpc-server/src/main/scala/com/avast/sst/grpc/server/GrpcServerConfig.scala

@@ -0,0 +1,11 @@
+package com.avast.sst.grpc.server
+
+import java.util.concurrent.TimeUnit
+
+import scala.concurrent.duration.Duration
+
+final case class GrpcServerConfig(port: Int,
+                                  handshakeTimeout: Duration,
+                                  maxInboundMessageSize: Int = 4 * 1024 * 1024,
+                                  maxInboundMetadataSize: Int = 8192,
+                                  serverShutdownTimeout: Duration = Duration(10, TimeUnit.SECONDS))

grpc-server/src/main/scala/com/avast/sst/grpc/server/GrpcServerModule.scala

@@ -0,0 +1,44 @@
+package com.avast.sst.grpc.server
+
+import java.util.concurrent.TimeUnit
+
+import cats.effect.{Resource, Sync}
+import io.grpc.{Server, ServerBuilder, ServerInterceptor, ServerServiceDefinition}
+
+import scala.collection.immutable.Seq
+import scala.concurrent.ExecutionContext
+object GrpcServerModule {
+
+  /** Makes [[io.grpc.Server]] (Netty) initialized with the given config, services and interceptors.
+    *
+    * @param services service implementations to be added to the handler registry
+    * @param executionContext executor to be used for the server
+    * @param interceptors that are run for all the services
+    */
+  @SuppressWarnings(Array("org.wartremover.warts.NonUnitStatements"))
+  def make[F[_]: Sync](config: GrpcServerConfig,
+                       services: Seq[ServerServiceDefinition],
+                       executionContext: ExecutionContext,
+                       interceptors: Seq[ServerInterceptor] = List.empty): Resource[F, Server] =
+    Resource.make {
+      Sync[F].delay {
+        val builder = ServerBuilder
+          .forPort(config.port)
+          .handshakeTimeout(config.handshakeTimeout.toMillis, TimeUnit.MILLISECONDS)
+          .maxInboundMessageSize(config.maxInboundMessageSize)
+          .maxInboundMetadataSize(config.maxInboundMetadataSize)
+          .executor(executionContext.execute)
+
+        services.foreach(builder.addService)
+        interceptors.foreach(builder.intercept)
+
+        builder.build.start()
+      }
+    } { s =>
+      Sync[F].delay {
+        s.shutdown().awaitTermination(config.serverShutdownTimeout.toMillis, TimeUnit.MILLISECONDS)
+        ()
+      }
+    }
+
+}

project/Dependencies.scala

@@ -7,6 +7,9 @@ object Dependencies {
   val doobie = "org.tpolecat" %% "doobie-core" % Versions.doobie
   val doobieHikari = "org.tpolecat" %% "doobie-hikari" % Versions.doobie
   val flywayCore = "org.flywaydb" % "flyway-core" % "6.1.2"
+  val grpcNettyShaded = "io.grpc" % "grpc-netty-shaded" % Versions.grpc
+  val grpcProtobuf = "io.grpc" % "grpc-protobuf" % Versions.grpc
+  val grpcStub = "io.grpc" % "grpc-stub" % Versions.grpc
   val http4sBlazeClient = "org.http4s" %% "http4s-blaze-client" % Versions.http4s
   val http4sBlazeServer = "org.http4s" %% "http4s-blaze-server" % Versions.http4s
   val http4sClient = "org.http4s" %% "http4s-client" % Versions.http4s
@@ -35,6 +38,7 @@ object Dependencies {
 
     val datastaxJavaDriverCore = "4.3.1"
     val doobie = "0.7.1"
+    val grpc = "1.25.0"
     val http4s = "0.20.15"
     val micrometerCore = "1.3.2"
     val micrometerJmx = "1.3.2"