🐛 Close MongoDB client

core/src/main/kotlin/io/saagie/updatarium/persist/PersistEngine.kt

@@ -52,6 +52,9 @@ abstract class PersistEngine(open val configuration: PersistConfig) {
 
     /**
      * This function is called after the changeSet execution, so you can now update the changeSet status (in the parameter) and store the logs.
+     *
+     * Your persist engine may use resources that should be close after the process,
+     * in that case, you need to cleanup theses resources in this method
      */
     protected abstract fun unlock(executionId: String, changeSet: ChangeSet, status: ExecutionStatus, logs: List<String>)
 

engine-mongodb/src/main/kotlin/io/saagie/updatarium/engine/mongo/MongoEngine.kt

@@ -23,14 +23,12 @@ import org.litote.kmongo.KMongo
 
 class MongoEngine(private val connectionStringEnvVar: String) {
 
-    val mongoClient by lazy { KMongo.createClient(ConnectionString(getConnectionString())) }
-
-    private fun getConnectionString(): String {
-        if (System.getenv().containsKey(connectionStringEnvVar)) {
-            return System.getenv(connectionStringEnvVar)
-        }
-        throw IllegalArgumentException("$connectionStringEnvVar is missing (environment variable)")
+    val mongoClient by lazy {
+        val connectionString = System.getenv(connectionStringEnvVar)
+            ?: throw IllegalArgumentException("$connectionStringEnvVar is missing (environment variable)")
+        KMongo.createClient(ConnectionString(connectionString))
     }
 
-    fun listDatabase(): MongoIterable<String> = mongoClient.listDatabaseNames()
+    fun listDatabase(): MongoIterable<String> =
+        mongoClient.listDatabaseNames()
 }

engine-mongodb/src/main/kotlin/io/saagie/updatarium/model/action/MongoScriptAction.kt

@@ -17,29 +17,38 @@
  */
 package io.saagie.updatarium.model.action
 
+import com.mongodb.client.MongoCollection
 import io.saagie.updatarium.engine.mongo.MongoEngine
 import io.saagie.updatarium.model.ChangeSetDsl
 import mu.KotlinLogging
+import org.bson.Document
 
 const val MONGODB_CONNECTIONSTRING = "MONGODB_CONNECTIONSTRING"
 
 fun ChangeSetDsl.mongoAction(
     connectionStringEnvVar: String = MONGODB_CONNECTIONSTRING,
     block: MongoScriptActionDsl.() -> Unit
 ) {
-    this.action { MongoScriptActionDsl(connectionStringEnvVar).block() }
+    this.action {
+        val actionDsl = MongoScriptActionDsl(connectionStringEnvVar)
+        try {
+            actionDsl.block()
+        } finally {
+            actionDsl.mongoClient.close();
+        }
+    }
 }
 
 class MongoScriptActionDsl(connectionStringEnvVar: String = MONGODB_CONNECTIONSTRING) {
     val logger = KotlinLogging.logger("mongoAction")
     val mongoEngine = MongoEngine(connectionStringEnvVar)
     val mongoClient = mongoEngine.mongoClient
 
-    fun onCollection(databaseName: String, collectionName: String) =
+    fun onCollection(databaseName: String, collectionName: String): MongoCollection<Document> =
         mongoClient.getDatabase(databaseName).getCollection(collectionName)
 
     fun onCollections(databaseNameRegex: Regex, collectionName: String) =
-        mongoClient.listDatabaseNames().filter { it.matches(databaseNameRegex) }.map {
-            mongoClient.getDatabase(it).getCollection(collectionName)
-        }
+        mongoClient.listDatabaseNames()
+            .filter { it.matches(databaseNameRegex) }
+            .map { mongoClient.getDatabase(it).getCollection(collectionName) }
 }

persist-mongodb/src/main/kotlin/io/saagie/updatarium/persist/MongodbPersistEngine.kt

@@ -18,6 +18,7 @@
 package io.saagie.updatarium.persist
 
 import com.mongodb.ConnectionString
+import com.mongodb.MongoClient
 import com.mongodb.client.model.IndexOptions
 import com.mongodb.client.model.Indexes
 import io.saagie.updatarium.model.ChangeSet
@@ -36,8 +37,12 @@ const val COLLECTION = "changeset"
 
 class MongodbPersistEngine(override val configuration: PersistConfig = PersistConfig()) : PersistEngine(configuration) {
 
+    private val client: MongoClient by lazy {
+        KMongo.createClient(ConnectionString(getConnectionString()))
+    }
+
     private val collection by lazy {
-        with(KMongo.createClient(ConnectionString(getConnectionString()))) {
+        with(client) {
             this.getDatabase(System.getenv().getOrDefault(MONGODB_PERSIST_DATABASE, DATABASE))
                 .getCollection<MongoDbChangeSet>(
                     System.getenv().getOrDefault(MONGODB_PERSIST_CHANGESET_COLLECTION, COLLECTION)
@@ -106,5 +111,7 @@ class MongodbPersistEngine(override val configuration: PersistConfig = PersistCo
             )
         )
         logger.info { "$executionId marked as $status" }
+        // Cleanup resources
+        this.client.close()
     }
 }