talachutla/user-management-lagom

User management service with Lagom

user-management-lagom

Basic implementation of a user management service using :

• Lagom 1.4.5
• Scala 2.12.6
• JBcrypt
• Cassandra
• Kafka

Get started

git clone https://github.com/botekchristophe/user-management-lagom.git

cd user-management-lagom

sbt runAll

curl -X POST http://localhost:9000/api/users \
  -d '{
	"username":"foo",
	"email": "foo@bar.com",
	"password": "barbarbar"
  }'

User service

API

  def descriptor: Descriptor = {
    import Service._
    named("user").withCalls(
      restCall(Method.GET,    "/api/users",              getUsers _),
      restCall(Method.POST,   "/api/users",              createUser _),
      restCall(Method.GET,    "/api/users/:id",          getUser _),
      restCall(Method.DELETE, "/api/users/:id",          deleteUser _),
      restCall(Method.PUT,    "/api/users/:id/verify",   verifyUser _),
      restCall(Method.PUT,    "/api/users/:id/unverify", unVerifyUser _),
      restCall(Method.POST,   "/api/users/auth",         getUserAuth _),
      restCall(Method.POST,   "/api/users/auth/grant",   userLogin _),
      restCall(Method.POST,   "/api/users/auth/revoke",  revokeToken _),
      restCall(Method.POST,   "/api/users/auth/refresh", refreshToken _)
    )
  }

Persistence entity

ReadSide - Cassandra

In order to demonstrate Cassandra Readside with Lagom, two tables are being updated by processing the event stream.

users table

id	username	status	email
$UUID	john	VERIFIED	$email
$UUID	Maddie	UNVERIFIED	$email

sessions table

access_token	refresh_token	userid
$UUID	$UUID	$UUID
$UUID	$UUID	$UUID

Model evolution

An example of model evolution can be found in UserEntity

object UserSerializerRegistry extends JsonSerializerRegistry {
  override def serializers = ...

  private val emailAdded = new JsonMigration(2) {
    override def transform(fromVersion: Int, json: JsObject): JsObject = {
      if (fromVersion < 2) {
        json + ("email" -> JsString("example@company.ca"))
      } else {
        json
      }
    }
  }

  override def migrations = Map[String, JsonMigration](
    classOf[CreateUser].getName -> emailAdded,
    classOf[UserCreated].getName -> emailAdded,
    classOf[UserAggregate].getName -> emailAdded
  )
}

Email service

API

trait EmailService extends Service {
  def getEmails: ServiceCall[NotUsed, List[EmailResponse]]

  def emailEvents: Topic[EmailKafkaEvent]

  def descriptor: Descriptor = {
    import Service._
    named("email").withCalls(
      restCall(Method.GET, "/api/emails", getEmails _)
    )
      .withAutoAcl(true)
      .withExceptionSerializer(new DefaultExceptionSerializer(Environment.simple(mode = Mode.Prod)))
      .withTopics(topic("EmailEvents", emailEvents))
  }
}

Persistence entity

ReadSide - Cassandra

In order to retrieve the history of emails processed.

email table

id	recipient	topic	content	status	date
uuid	me@me.ca	Welcome	Hello user	DELIVERED	timestamp

Further work - unit testing

Cheers