Initial work on scheduled backups.

foundation-core/build.gradle.kts

@@ -2,4 +2,5 @@ dependencies {
   // TODO: might be able to ship all dependencies in core? are we duplicating classes in JARs?
 
   implementation("software.amazon.awssdk:s3:2.17.102")
+  implementation("org.quartz-scheduler:quartz:2.3.2")
 }

foundation-core/src/main/kotlin/cloud/kubelet/foundation/core/FoundationCorePlugin.kt

@@ -8,6 +8,7 @@ import cloud.kubelet.foundation.core.features.stats.StatsFeature
 import cloud.kubelet.foundation.core.features.update.UpdateFeature
 import cloud.kubelet.foundation.core.features.world.WorldFeature
 import cloud.kubelet.foundation.core.features.persist.PersistenceFeature
+import cloud.kubelet.foundation.core.features.scheduler.SchedulerFeature
 import org.koin.dsl.module
 import java.nio.file.Path
 
@@ -38,6 +39,7 @@ class FoundationCorePlugin : FoundationPlugin() {
   }
 
   override fun createFeatures() = listOf(
+    SchedulerFeature(),
     PersistenceFeature(),
     BackupFeature(),
     DevFeature(),

foundation-core/src/main/kotlin/cloud/kubelet/foundation/core/abstraction/CoreFeature.kt

@@ -0,0 +1,7 @@
+package cloud.kubelet.foundation.core.abstraction
+
+interface CoreFeature {
+  fun enable()
+  fun disable()
+  fun module() = org.koin.dsl.module {}
+}

foundation-core/src/main/kotlin/cloud/kubelet/foundation/core/abstraction/Feature.kt

@@ -7,13 +7,15 @@ import org.bukkit.event.Listener
 import org.koin.core.component.KoinComponent
 import org.koin.core.component.inject
 import org.koin.dsl.module
+import org.quartz.Scheduler
 
-abstract class Feature : KoinComponent, Listener {
+abstract class Feature : CoreFeature, KoinComponent, Listener {
   private val plugin by inject<FoundationCorePlugin>()
+  protected val scheduler by inject<Scheduler>()
 
-  open fun enable() {}
-  open fun disable() {}
-  open fun module() = module {}
+  override fun enable() {}
+  override fun disable() {}
+  override fun module() = module {}
 
   protected fun registerCommandExecutor(name: String, executor: CommandExecutor) {
     registerCommandExecutor(listOf(name), executor)

foundation-core/src/main/kotlin/cloud/kubelet/foundation/core/abstraction/FoundationPlugin.kt

@@ -10,7 +10,7 @@ import org.koin.dsl.module
 abstract class FoundationPlugin : JavaPlugin() {
   private lateinit var pluginModule: Module
   private lateinit var pluginApplication: KoinApplication
-  private lateinit var features: List<Feature>
+  private lateinit var features: List<CoreFeature>
   private lateinit var module: Module
 
   override fun onEnable() {
@@ -45,7 +45,10 @@ abstract class FoundationPlugin : JavaPlugin() {
       try {
         slF4JLogger.info("Enabling feature: ${it.javaClass.simpleName}")
         it.enable()
-        server.pluginManager.registerEvents(it, this)
+        // TODO: May replace this check with a method in the interface, CoreFeature would no-op.
+        if (it is Feature) {
+          server.pluginManager.registerEvents(it, this)
+        }
       } catch (e: Exception) {
         slF4JLogger.error("Failed to enable feature: ${it.javaClass.simpleName}", e)
       }
@@ -61,5 +64,5 @@ abstract class FoundationPlugin : JavaPlugin() {
   }
 
   protected open fun createModule() = module {}
-  protected abstract fun createFeatures(): List<Feature>
+  protected abstract fun createFeatures(): List<CoreFeature>
 }

foundation-core/src/main/kotlin/cloud/kubelet/foundation/core/features/backup/BackupConfig.kt

@@ -4,9 +4,15 @@ import kotlinx.serialization.Serializable
 
 @Serializable
 data class BackupConfig(
+  val schedule: ScheduleConfig = ScheduleConfig(),
   val s3: S3Config = S3Config(),
 )
 
+@Serializable
+data class ScheduleConfig(
+  val cron: String = "",
+)
+
 @Serializable
 data class S3Config(
   val accessKeyId: String = "",

foundation-core/src/main/kotlin/cloud/kubelet/foundation/core/features/backup/BackupFeature.kt

@@ -3,8 +3,9 @@ package cloud.kubelet.foundation.core.features.backup
 import cloud.kubelet.foundation.core.FoundationCorePlugin
 import cloud.kubelet.foundation.core.Util
 import cloud.kubelet.foundation.core.abstraction.Feature
+import cloud.kubelet.foundation.core.features.scheduler.cancel
+import cloud.kubelet.foundation.core.features.scheduler.cron
 import com.charleskorn.kaml.Yaml
-import org.koin.core.KoinApplication
 import org.koin.core.component.inject
 import org.koin.dsl.module
 import software.amazon.awssdk.auth.credentials.AwsSessionCredentials
@@ -18,6 +19,7 @@ class BackupFeature : Feature() {
   private val plugin by inject<FoundationCorePlugin>()
   private val s3Client by inject<S3Client>()
   private val config by inject<BackupConfig>()
+  private lateinit var scheduleId: String
 
   override fun enable() {
     // Create backup directory.
@@ -25,6 +27,20 @@ class BackupFeature : Feature() {
     backupPath.toFile().mkdir()
 
     registerCommandExecutor("fbackup", BackupCommand(plugin, backupPath, config, s3Client))
+
+    if (config.schedule.cron.isNotEmpty()) {
+      scheduleId = scheduler.cron("${config.schedule.cron} ?") {
+        plugin.server.scheduler.runTask(plugin) { ->
+          plugin.server.dispatchCommand(plugin.server.consoleSender, "fbackup")
+        }
+      }
+    }
+  }
+
+  override fun disable() {
+    if (::scheduleId.isInitialized) {
+      scheduler.cancel(scheduleId)
+    }
   }
 
   override fun module() = module {

foundation-core/src/main/kotlin/cloud/kubelet/foundation/core/features/scheduler/SchedulerExtensions.kt

@@ -0,0 +1,30 @@
+package cloud.kubelet.foundation.core.features.scheduler
+
+import org.quartz.CronScheduleBuilder.cronSchedule
+import org.quartz.JobBuilder.newJob
+import org.quartz.JobDataMap
+import org.quartz.Scheduler
+import org.quartz.TriggerBuilder.newTrigger
+import org.quartz.TriggerKey.triggerKey
+import java.util.UUID
+
+fun Scheduler.cron(cronExpression: String, f: () -> Unit): String {
+  val id = UUID.randomUUID().toString()
+  val job = newJob(SchedulerRunner::class.java).apply {
+    setJobData(JobDataMap().apply {
+      set("function", f)
+    })
+  }.build()
+
+  val trigger = newTrigger()
+    .withIdentity(triggerKey(id))
+    .withSchedule(cronSchedule(cronExpression))
+    .build()
+
+  scheduleJob(job, trigger)
+  return id
+}
+
+fun Scheduler.cancel(id: String) {
+  unscheduleJob(triggerKey(id))
+}

foundation-core/src/main/kotlin/cloud/kubelet/foundation/core/features/scheduler/SchedulerFeature.kt

@@ -0,0 +1,22 @@
+package cloud.kubelet.foundation.core.features.scheduler
+
+import cloud.kubelet.foundation.core.abstraction.CoreFeature
+import org.koin.dsl.module
+import org.quartz.Scheduler
+import org.quartz.impl.StdSchedulerFactory
+
+class SchedulerFeature : CoreFeature {
+  private val scheduler: Scheduler = StdSchedulerFactory.getDefaultScheduler()
+
+  override fun enable() {
+    scheduler.start()
+  }
+
+  override fun disable() {
+    scheduler.shutdown(true)
+  }
+
+  override fun module() = module {
+    single { scheduler }
+  }
+}

foundation-core/src/main/kotlin/cloud/kubelet/foundation/core/features/scheduler/SchedulerRunner.kt

@@ -0,0 +1,11 @@
+package cloud.kubelet.foundation.core.features.scheduler
+
+import org.quartz.Job
+import org.quartz.JobExecutionContext
+
+class SchedulerRunner : Job {
+  override fun execute(context: JobExecutionContext) {
+    val f = context.jobDetail.jobDataMap["function"] as () -> Unit
+    f()
+  }
+}

foundation-core/src/main/resources/backup.yaml

@@ -1,3 +1,11 @@
+# Configuration of backup scheduling, expressed by cron expressions.
+schedule:
+  # Cron expression to use for the backup schedule.
+  # Examples:
+  # "0 3 * * *"   -> every day at 3 AM
+  # "0 3 * * SUN" -> every Sunday at 3 AM
+  cron: ""
+
 # Configuration of S3 service to upload back-ups to.
 s3:
   # The access key ID from your S3-compliant storage provider.

foundation-core/src/main/resources/quartz.properties

@@ -0,0 +1,3 @@
+org.quartz.scheduler.instanceName = Foundation
+org.quartz.threadPool.threadCount = 2
+org.quartz.jobStore.class = org.quartz.simpl.RAMJobStore