playing-aws-scala

The following blog and attached code represent a simple example of Amazon Web Services in the Scala way with Play Framework using AWScala but in this blog I have implemented only Amazon Simple Storage Service (Amazon S3) functionalities.

AWScala: AWS SDK on the Scala REPL

AWScala enables Scala developers to easily work with Amazon Web Services in the Scala way.

Though AWScala objects basically extend AWS SDK for Java APIs, you can use them with less stress on Scala REPL or sbt console.

AWScala Supported Services

AWS Identity and Access Management (IAM)
AWS Security Token Service (STS)
Amazon Elastic Compute Cloud (Amazon EC2)
Amazon Simple Storage Service (Amazon S3)
Amazon Simple Queue Service（Amazon SQS）
Amazon Redshift
Amazon DynamoDB
Amazon SimpleDB

Amazon Simple Storage Service (Amazon S3)

S3Utility to create/upload bucket/file on AWS S3: S3Utility.scala

package utils

import awscala._, s3._

object S3Utility extends S3Utility

trait S3Utility {

  implicit val s3 = S3()

  /**
   * Get all the available buckets
   *
   * @return
   */
  def getBuckets(): Seq[Bucket] = s3.buckets

  /**
   * Get the bucket by given name
   *
   * @param name The Bucket name
   * @return
   */
  def getBucketByName(name: String): Option[Bucket] = s3.bucket(name)

  /**
   * Create new bucket for given name
   *
   * @param name The Bucket name
   * @return
   */
  def createBucket(name: String): Bucket = s3.createBucket(name)

  /**
   * Create an object into given bucket by name
   *
   * @param bucket The Bucket
   * @param name The Object name
   * @param file The Object
   * @return
   */
  def createObject(bucket: Bucket, name: String, file: File): PutObjectResult = bucket.put(name, file)

  /**
   * Get the Object by given name from given bucket
   *
   * @param bucket The Bucket
   * @param name The Object name
   * @return
   */
  def getObject(bucket: Bucket, name: String): Option[S3Object] = bucket.getObject(name)

}

Multipart form upload handlers looks like this: Application.scala

  val uploadService: UploadService

  def upload = Action(parse.multipartFormData) { implicit request =>
    val result = uploadService.uploadFile(request)
    Redirect(routes.Application.index).flashing("message" -> result)
  }

Service for upload file looks like this: UploadService.scala

  /**
   * Get file from the request and move it in your location
   *
   * @param request
   * @return
   */
  def uploadFile(request: Request[MultipartFormData[TemporaryFile]]): String = {
    log.error("Called uploadFile function" + request)
    request.body.file("file").map { file =>
      import java.io.File
      val filename = file.filename
      val contentType = file.contentType
      log.error(s"File name : $filename, content type : $contentType")
      val uniqueFile = new File(s"/tmp/${UUID.randomUUID}_$filename")
      file.ref.moveTo(uniqueFile, true)
      if (Play.isProd) {
        try {
          val bucket = s3Utility.getBucketByName("test").getOrElse(s3Utility.createBucket("test"))
          val result = s3Utility.createObject(bucket, filename, uniqueFile)
          s"File uploaded on S3 with Key : ${result.key}"
        } catch {
          case t: Throwable => log.error(t.getMessage, t); t.getMessage
        }
      } else {
        s"File(${filename}) uploaded"
      }
    }.getOrElse {
      "Missing file"
    }
  }

Test Code for Controller and Service

ApplicationSpec.scala

"should be valid" in new WithApplication {
  val request = mock[Request[MultipartFormData[TemporaryFile]]]
  mockedUploadService.uploadFile(request) returns "File Uploaded"
  val result: Future[Result] = TestController.upload().apply(request)
  status(result) must equalTo(SEE_OTHER)
}

UploadServiceSpec.scala

"UploadService" should {
    "uploadFile returns (File uploaded)" in new WithApplication {
      val files = Seq[FilePart[TemporaryFile]](FilePart("file", "UploadServiceSpec.scala", None, TemporaryFile("file", "spec")))
      val multipartBody = MultipartFormData(Map[String, Seq[String]](), files, Seq[BadPart](), Seq[MissingFilePart]())
      val fakeRequest = FakeRequest[MultipartFormData[Files.TemporaryFile]]("POST", "/", FakeHeaders(), multipartBody)
      val success = UploadService.uploadFile(fakeRequest)
      success must beEqualTo("File uploaded")
    }

    "uploadFile returns (Missing file)" in new WithApplication {
      val files = Seq[FilePart[TemporaryFile]]()
      val multipartBody = MultipartFormData(Map[String, Seq[String]](), files, Seq[BadPart](), Seq[MissingFilePart]())
      val fakeRequest = FakeRequest[MultipartFormData[Files.TemporaryFile]]("POST", "/", FakeHeaders(), multipartBody)
      val success = UploadService.uploadFile(fakeRequest)
      success must beEqualTo("Missing file")
    }
}

AWS credentials! Make sure about environment or configuration

export AWS_ACCESS_KEY_ID=<ACCESS_KEY>
export AWS_SECRET_KEY=<SECRET_KEY>

Build and Run the application

To run the Play Framework, you need JDK 6 or later
Install Typesafe Activator if you do not have it already. You can get it from here
Execute ./activator clean compile to build the product
Execute ./activator run to execute the product
playing-aws-scala should now be accessible at localhost:9000

Test the application with code coverage

Execute $ ./activator clean coverage test to test
Execute $ ./activator coverageReport to generate coverage report

References :-

This is the start of AWS Services implementation, from next week onwards we would be working on this application to make it grow. We would look at how we can make it more functional, then we would be adding more AWS modules to it together. If you have any changes then feel free to send in pull requests and we would do the merges 🙂 Stay tuned.