Scala Play AWS SNS

// Let's test Amazon SNS (Simple Notification Service)

// 1. Sign in to AWS Console and create new SNS App
// 2. Specify AWS region (e.g. EU-CENTRAL-1 (Frankfurt))
// 3. Create topic (e.g. "Student-Alerts", display name: "StudAlerts")
// Amazon will generate new ARN (Amazon Resource Name) for your topic. e.g.
arn:aws:sns:eu-central-1:760693603791:Student-Alerts

// 4. Specify 1 or more subscriptions, e.g. email address "example@yandex.ru"
// Amazon will send a confirmation to your e-mail, you need to confirm the subscription
// 5. [Troubleshooting] aside from following confirmation URL in your e-mail, it seems that you also need to click
// on 'Confirm subscription' in SNS Console and copy-paste that URL to get it work.

// 6. Add AWS credintials in your ENV variables (please note that it may be done via source code as well):
export AWS_ACCESS_KEY_ID=BVSAJ7UKCRP53EXTFQ2A
export AWS_SECRET_ACCESS_KEY=4hg17YxGUyqpFIRTa/k2hwvco8QwqxT/KVH0HwdB

// 7. Preliminary work is done! Let's write a code:
// build.sbt:
libraryDependencies += "com.lightbend.akka" %% "akka-stream-alpakka-sns" % "0.18"

// SnsStudents.scala:
import javax.inject.Inject

import scala.concurrent.Future

import akka.Done
import akka.stream.Materializer
import akka.stream.alpakka.sns.scaladsl.SnsPublisher
import akka.stream.scaladsl.Source
import com.amazonaws.regions.Regions
import com.amazonaws.services.sns.{AmazonSNSAsync, AmazonSNSAsyncClientBuilder}

class SnsStudents @Inject() (implicit mat: Materializer) {
  protected lazy implicit val snsClient: AmazonSNSAsync = AmazonSNSAsyncClientBuilder
    .standard()
    //.withCredentials(new AWSStaticCredentialsProvider(new BasicAWSCredentials("a", "b"))) // you can also use ENV vars
    .withRegion(Regions.EU_CENTRAL_1) // may be specified here or via ENV variables
    .build()

  def pushNotification(msg: String): Future[Done] = {
    Source.single(msg).runWith(SnsPublisher.sink("arn:aws:sns:eu-central-1:760693603791:Student-Alerts"))
  }
}

// TestController.scala:
import javax.inject.Inject
import scala.concurrent.{ExecutionContext, Future}
import play.api.libs.json._
import play.api.mvc._
import services._

class MitrakovController @Inject()(
    cc: ControllerComponents,
    snsStudents: SnsStudents)
  (implicit ec: ExecutionContext) extends AbstractController(cc) {

  // add to routes: POST    /push    controllers.TestController.pushNotification
  def pushNotification: Action[JsValue] = Action(parse.json).async { request =>
    (request.body \ "text").asOpt[String] match {
      case Some(msg) =>
        snsStudents.pushNotification(msg) map { done =>
          Ok(s"Result is: $done")
        } recover { case ex =>
          BadRequest(s"Error: $ex")
        }
      case None => Future.successful(BadRequest("Incorrect Json: 'text' attribute expected"))
    }
  }
}

// 8. Now open curl, Postman or any other tool you wish and run:
http://localhost:9000/push with json body: {"text": "We're gonna make that energy!"}

    // Email output: We're gonna make that energy!
    // --
    // If you wish to stop receiving notifications from this topic, please click or visit the link below to unsubscribe:
    // https://sns.eu-central-1.amazonaws.com/unsubscribe.html?SubscriptionArn=arn:aws:sns:eu-central-1:760693603791:Student-Alerts:2df1740c-c7b6-4643-9b1b-ea32c891cdbf&Endpoint=tom-trix@ya.ru
    // Please do not reply directly to this email. If you have any questions or comments regarding this email, please contact us at https://aws.amazon.com/support