ReactiveMongoConnection

gistfile1.scala

class ReactiveMongoConnection extends Module {
  import ExecutionContext.Implicits.global

  private val config = ConfigFactory.load()
  implicit val context = inject[ActorSystem]
  val driver = new MongoDriver

  val pattern = "^mongodb:\\/\\/([\\w]*):([\\w]*)@([\\w\\.-]+):([\\d]+)\\/([\\w]+)".r

  val envUri = Properties.envOrElse("MONGOLAB_URI", "").toString

  val (connection, db) = if (!envUri.isEmpty){
    val pattern(user, password, host, port, dbName) = envUri

    val connection = driver.connection(List("%s:%s".format(host, port)))

    val userName =Properties.envOrElse("MONGODB_USER", "FAIL")
    val pass = Properties.envOrElse("MONGODB_PASS", "FAIL")

    // Gets a reference to the database "plugin"
    val db = connection(dbName)
    val authResult = Await.result(db.authenticate(userName, pass)(120.seconds), 120.seconds)

    (connection, db)

  }
  else {
    val connection = driver.connection(List(config.getString("mongodb.url")))

    // Gets a reference to the database "plugin"
    val db = connection(config.getString("mongodb.database"))

    (connection, db)
  }

  // Gets a reference to the collection "acoll"
  // By default, you get a BSONCollection.
  bind[DB] to db
  bind[BSONCollection] as 'vaultCollection to db(config.getString("infescrow.vault.collection"))
  bind[BSONCollection] as 'dataCollection to db(config.getString("infescrow.vaultdata.collection"))
  bind[BSONCollection] as 'userCollection to db(config.getString("infescrow.user.collection"))
  bind[BSONCollection] as 'inviteCollection to db(config.getString("infescrow.invite.collection"))
  bind[BSONCollection] as 'stateCollection to db(config.getString("infescrow.userstate.collection"))


//  userCollection.indexesManager.ensure(Index(
//    key = Seq("email" -> IndexType.Ascending),
//    unique = true,
//    dropDups = true
//  ))
}

I would rewrite it this way, to make sure that inject is called lazily:

class ReactiveMongoConnection extends Module {
  binding to ConfigFactory.load()

  bind[DB] to {
    import ExecutionContext.Implicits.global

    implicit val context = inject [ActorSystem]

    val driver = new MongoDriver

    val pattern = "^mongodb:\\/\\/([\\w]*):([\\w]*)@([\\w\\.-]+):([\\d]+)\\/([\\w]+)".r

    val envUri = Properties.envOrElse("MONGOLAB_URI", "").toString

    if (!envUri.isEmpty){
      val pattern(user, password, host, port, dbName) = envUri

      val connection = driver.connection(List("%s:%s".format(host, port)))

      val userName =Properties.envOrElse("MONGODB_USER", "FAIL")
      val pass = Properties.envOrElse("MONGODB_PASS", "FAIL")

      // Gets a reference to the database "plugin"
      val db = connection(dbName)
      val authResult = Await.result(db.authenticate(userName, pass)(120.seconds), 120.seconds)

      db
    } else {
      val connection = driver.connection(List(inject[Config].getString("mongodb.url")))

      // Gets a reference to the database "plugin"
      val db = connection(inject[Config].getString("mongodb.database"))

      db
    }
  }

  bind[BSONCollection] as 'vaultCollection to db(inject[Config].getString("infescrow.vault.collection"))
  bind[BSONCollection] as 'dataCollection to db(inject[Config].getString("infescrow.vaultdata.collection"))
  bind[BSONCollection] as 'inviteCollection to db(inject[Config].getString("infescrow.invite.collection"))
  bind[BSONCollection] as 'stateCollection to db(inject[Config].getString("infescrow.userstate.collection"))
  bind[BSONCollection] as 'userCollection to db(inject[Config].getString("infescrow.user.collection")) initWith { collection =>
    collection.indexesManager.ensure(Index(
      key = Seq("email" -> IndexType.Ascending),
      unique = true,
      dropDups = true
    )) 
  }

  private def db = inject [DB]
}