[#552] Allow to specify mongo authentication database different from data database

# New features and improvements

Now the user can specify an authentication database to mongo that is different from the data database
through the configuration key `wasp.mongo.authentication-db`. Default value is `${wasp.mongo.db-name}`
so that the default behavior is consistent.

# Breaking changes

Potentially binary incompatible change: `ConfigManager` was a Scala `object`, making it hard to test dynamically injected configuration values. I split it into a `class` (with the whole implementation) and an `object` extending the `class`. In this way all usages do not need any source change.

# Migration

None.

# Bug fixes

None.

# How this feature was tested

`ConfigManagerSpec` and existing tests.

# Related issue

Closes #552

Author: agilelab-tmnd1991

core/src/main/resources/reference.conf

@@ -121,6 +121,7 @@ wasp {
     password = ""
     timeout = ${wasp.services-timeout-millis}
     collection-prefix = ""
+    authentication-db = ${wasp.mongo.db-name}
   }
 
   kafka {

core/src/main/scala/it/agilelab/bigdata/wasp/core/models/configuration/ValidationRule.scala

@@ -2,9 +2,9 @@ package it.agilelab.bigdata.wasp.core.models.configuration
 
 import it.agilelab.bigdata.wasp.core.utils.ConfigManager
 
-class ValidationRule(val key: String, val func: (ConfigManager.type) => Either[String, Unit])
+class ValidationRule(val key: String, val func: (ConfigManager) => Either[String, Unit])
 
 object ValidationRule {
   def apply(key: String)
-           (func: (ConfigManager.type) => Either[String, Unit]): ValidationRule = new ValidationRule(key, func)
+           (func: (ConfigManager) => Either[String, Unit]): ValidationRule = new ValidationRule(key, func)
 }

core/src/main/scala/it/agilelab/bigdata/wasp/core/utils/ConfigManager.scala

@@ -16,7 +16,8 @@ import scala.collection.JavaConverters._
 import scala.reflect.ClassTag
 import scala.reflect.runtime.universe._
 
-object ConfigManager extends Logging with CanOverrideNameInstances {
+object ConfigManager extends ConfigManager
+class ConfigManager extends Logging with CanOverrideNameInstances {
   val conf: Config = ConfigFactory.load.getConfig("wasp") // grab the "wasp" subtree, as everything we need is in that namespace
 
   val kafkaConfigName = "Kafka"
@@ -237,6 +238,7 @@ object ConfigManager extends Logging with CanOverrideNameInstances {
       mongoDBSubConfig.getString("db-name"),
       mongoDBSubConfig.getString("username"),
       mongoDBSubConfig.getString("password"),
+      mongoDBSubConfig.getString("authentication-db"),
       mongoDBSubConfig.getInt("timeout"),
       mongoDBSubConfig.getString("collection-prefix")
     )

core/src/test/scala/it/agilelab/bigdata/wasp/core/utils/ConfigManagerSpec.scala

@@ -0,0 +1,24 @@
+package it.agilelab.bigdata.wasp.core.utils
+
+import com.typesafe.config.{Config, ConfigFactory, ConfigValueFactory}
+import org.scalatest.{FlatSpec, Matchers}
+
+class ConfigManagerSpec extends FlatSpec with Matchers {
+
+  it should "load the basic Mongo configuration without errors" in {
+    noException shouldBe thrownBy(ConfigManager.getMongoDBConfig)
+  }
+
+  it should "use the default database as the credential database" in {
+    val mongoConf = ConfigManager.getMongoDBConfig
+    mongoConf.credentialDb shouldBe mongoConf.databaseName
+  }
+
+  it should "be possible to override the credential database" in {
+    val anotherConfigManager = new ConfigManager {
+      override val conf: Config = ConfigFactory.load().getConfig("wasp").withValue("mongo.authentication-db", ConfigValueFactory.fromAnyRef("admin"))
+    }
+    anotherConfigManager.getMongoDBConfig.credentialDb shouldBe "admin"
+  }
+
+}

model/src/main/scala/it/agilelab/bigdata/wasp/models/configuration/MongoDBConfigModel.scala

@@ -4,5 +4,6 @@ case class MongoDBConfigModel(address: String,
                               databaseName: String,
                               username: String,
                               password: String,
+                              credentialDb: String,
                               millisecondsTimeoutConnection: Int,
                               collectionPrefix: String)

repository/mongo/src/main/scala/it/agilelab/bigdata/wasp/repository/mongo/WaspMongoDB.scala

@@ -507,7 +507,7 @@ object WaspMongoDB extends Logging {
     println(s"Dropping MongoDB database '${mongoDBConfig.databaseName}'")
     val mongoDBDatabase = MongoDBHelper.getDatabase(mongoDBConfig)
     val dropFuture      = mongoDBDatabase.drop().toFuture()
-    Await.result(dropFuture, Duration(10, TimeUnit.SECONDS))
+    Await.result(dropFuture, Duration(mongoDBConfig.millisecondsTimeoutConnection, TimeUnit.MILLISECONDS))
     println(s"Dropped MongoDB database '${mongoDBConfig.databaseName}'")
     System.exit(0)
 
@@ -518,9 +518,7 @@ object WaspMongoDB extends Logging {
   def initializeDB(): WaspMongoDB = {
     // MongoDB initialization
     val mongoDBConfig = ConfigManager.getMongoDBConfig
-    logger.info(
-      s"Create connection to MongoDB: address ${mongoDBConfig.address}, databaseName: ${mongoDBConfig.databaseName}"
-    )
+    logger.info(s"Create connection to MongoDB:\n" + printMongoConfigModel(mongoDBConfig))
 
     val codecRegistry = fromRegistries(
       fromProviders(codecProviders),

repository/mongo/src/main/scala/it/agilelab/bigdata/wasp/repository/mongo/utils/MongoDBHelper.scala

@@ -192,7 +192,7 @@ object MongoDBHelper extends Logging {
     val settings = if(mongoDBConfig.username != ""){
       settingsBuilder.credential(MongoCredential.createCredential(
         mongoDBConfig.username,
-        mongoDBConfig.databaseName,
+        mongoDBConfig.credentialDb,
         mongoDBConfig.password.toCharArray)).build()
     } else {
       settingsBuilder.build()
@@ -201,11 +201,8 @@ object MongoDBHelper extends Logging {
     resultTimeout = Duration(mongoDBConfig.millisecondsTimeoutConnection, TimeUnit.MILLISECONDS)
 
     mongoClient = MongoClient(settings)
-    //sys.addShutdownHook(() -> {
-    //  close()
-    //})
     val mongoDatabase = mongoClient.getDatabase(mongoDBConfig.databaseName)
-
+    // this is done to eagerly initialize connection and fail as early as possible if something is wrong
     mongoDatabase.listCollectionNames().results()
     mongoDatabase
   }
@@ -246,4 +243,15 @@ object MongoDBHelper extends Logging {
         key -> value
     } toMap
   }
+
+  def printMongoConfigModel(mongoDBConfigModel: MongoDBConfigModel): String = {
+
+      s"""address: ${mongoDBConfigModel.address},
+         |databaseName: ${mongoDBConfigModel.databaseName},
+         |username: ${mongoDBConfigModel.username},
+         |password: ************,
+         |credentialDb: ${mongoDBConfigModel.credentialDb},
+         |millisecondsTimeoutConnection: ${mongoDBConfigModel.millisecondsTimeoutConnection},
+         |collectionPrefix: ${mongoDBConfigModel.collectionPrefix}""".stripMargin
+  }
 }

repository/mongo/src/test/resources/application.conf

@@ -0,0 +1 @@
+wasp.mongo.authentication-db: admin