More build/etc

Author: ScalaWilliam

examples/fs2-echo/build.sbt

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+ThisBuild / resolvers += Resolver.sonatypeRepo("snapshots")
+
+scalaVersion := "2.13.6"
+
+libraryDependencies ++= Seq(
+  "co.fs2"           %% "fs2-io"          % "3.0.1",
+  "com.scalawilliam" %% "letsencrypt-ce3" % "0.0.5-SNAPSHOT"
+)
+
+reStartArgs += "--insecure"

examples/fs2-echo/project/build.properties

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+sbt.version=1.5.5

examples/fs2-echo/project/plugins.sbt

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+addSbtPlugin("io.spray"         % "sbt-revolver"        % "0.9.1")
+addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % "1.8.1")

examples/fs2-echo/src/main/scala/com/scalawilliam/FS2LetsEncryptEchoApp.scala

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+package com.scalawilliam
+
+import cats.effect.kernel.{Async, Sync}
+import cats.effect.{ExitCode, IO, IOApp, Resource}
+import com.comcast.ip4s.Port
+import com.scalawilliam.letsencrypt.LetsEncryptScala
+import fs2.io.net.tls.TLSContext
+import fs2.io.net.{Network, Socket}
+import fs2.{INothing, Stream, text}
+import cats.effect.Concurrent
+
+object FS2LetsEncryptEchoApp extends IOApp {
+
+  type SocketHandler[F[_]] = Socket[F] => Stream[F, INothing]
+
+  /** Respond to a client socket with echoes - if they send a line, we return a line */
+  private def handleEchoes[F[_]: Concurrent]: SocketHandler[F] =
+    client =>
+      client.reads
+        .through(text.utf8Decode)
+        .through(text.lines)
+        .interleave(Stream.constant("\n"))
+        .through(text.utf8Encode)
+        .through(client.writes)
+        /** This is VERY important; if you don't handle errors, the whole server will go down;
+          * One example is if a plaintext client connects to an SSL server */
+        .handleErrorWith(_ => Stream.empty)
+
+  private def runTcpServer[F[_]: Concurrent: Network](
+      forHandler: SocketHandler[F]
+  ): F[Unit] =
+    Network[F]
+      .server(port = Port.fromInt(5555))
+      .map(forHandler)
+      .parJoin(100)
+      .compile
+      .drain
+
+  /** Utility function to pipe a socket through SSL.
+    * This is a prime example of composition in functional programming:
+    * you merely 'secure' a socket handler, without having to
+    * modify any of the plaintext server code.
+    *
+    * We have to use a 'Resource' here because the SSL Context
+    * is something we should let go of once not needed any more.
+    * */
+  private def secureHandler[F[_]: Concurrent: Sync: Async](
+      originalHandler: SocketHandler[F]
+  ): Resource[F, SocketHandler[F]] =
+    LetsEncryptScala
+      .fromEnvironment[F]
+      .flatMap(_.sslContextResource)
+      .map(TLSContext.Builder.forAsync[F].fromSSLContext)
+      .map { tlsContext => (clientSocket: Socket[F]) =>
+        fs2.Stream
+          .resource(tlsContext.server(clientSocket))
+          .flatMap(originalHandler)
+      }
+
+  private def secureConditionally[F[_]: Concurrent: Sync: Async](
+      enableSecurity: Boolean,
+      handler: SocketHandler[F]
+  ): Resource[F, SocketHandler[F]] =
+    if (enableSecurity) secureHandler(handler)
+    else Resource.pure(handler)
+
+  override def run(args: List[String]): IO[ExitCode] =
+    secureConditionally[IO](
+      enableSecurity = !args.contains("--insecure"),
+      handler = handleEchoes
+    ).use(handler => runTcpServer(handler).as(ExitCode.Success))
+
+}

examples/http4s/project/build.properties

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+sbt.version=1.5.5

examples/http4s/project/plugins.sbt

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+addSbtPlugin("io.spray"         % "sbt-revolver"        % "0.9.1")
+addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % "1.8.1")

examples/play/project/build.properties

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+sbt.version=1.5.5

examples/play/project/plugins.sbt

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+addSbtPlugin("com.typesafe.play" % "sbt-plugin" % "2.8.8")