add scheduled task example

pom.xml

@@ -28,6 +28,7 @@
     <module>initializer</module>
 		<module>actiontoken</module>
 		<module>admin-ui</module>
+		<module>scheduled-task</module>
 	</modules>
 
 	<properties>

scheduled-task/pom.xml

@@ -0,0 +1,62 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+				 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+				 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<parent>
+		<groupId>dasniko.keycloak</groupId>
+		<artifactId>keycloak-extensions-demo</artifactId>
+		<version>1.0-SNAPSHOT</version>
+	</parent>
+
+	<artifactId>scheduled-task</artifactId>
+	<version>1.0-SNAPSHOT</version>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.keycloak</groupId>
+			<artifactId>keycloak-core</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.keycloak</groupId>
+			<artifactId>keycloak-server-spi</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.keycloak</groupId>
+			<artifactId>keycloak-server-spi-private</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.keycloak</groupId>
+			<artifactId>keycloak-services</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.google.auto.service</groupId>
+			<artifactId>auto-service</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.projectlombok</groupId>
+			<artifactId>lombok</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.slf4j</groupId>
+			<artifactId>slf4j-api</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.cronutils</groupId>
+			<artifactId>cron-utils</artifactId>
+			<version>9.2.1</version>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<finalName>${project.groupId}-${project.artifactId}</finalName>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-shade-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

scheduled-task/src/main/java/dasniko/keycloak/timer/ExampleScheduledTaskProvider.java

@@ -0,0 +1,22 @@
+package dasniko.keycloak.timer;
+
+import lombok.extern.slf4j.Slf4j;
+import org.keycloak.cluster.ClusterProvider;
+import org.keycloak.timer.ScheduledTask;
+
+@Slf4j
+public class ExampleScheduledTaskProvider implements ScheduledTaskProvider {
+
+	@Override
+	public ScheduledTask getScheduledTask() {
+		return session -> {
+			//noinspection deprecation
+			ClusterProvider cluster = session.getProvider(ClusterProvider.class);
+			cluster.executeIfNotExecuted(ExampleScheduledTaskProviderFactory.PROVIDER_ID + "::scheduled", 10000, () -> {
+				log.info("I'm being executed... realm: {}", session.getContext().getRealm());
+				return null;
+			});
+		};
+	}
+
+}

scheduled-task/src/main/java/dasniko/keycloak/timer/ExampleScheduledTaskProviderFactory.java

@@ -0,0 +1,21 @@
+package dasniko.keycloak.timer;
+
+import com.google.auto.service.AutoService;
+import org.keycloak.models.KeycloakSession;
+
+@AutoService(ScheduledTaskProviderFactory.class)
+public class ExampleScheduledTaskProviderFactory extends ScheduledTaskProviderFactory {
+
+	public static final String PROVIDER_ID = "example";
+
+	@Override
+	public ScheduledTaskProvider create(KeycloakSession session) {
+		return new ExampleScheduledTaskProvider();
+	}
+
+	@Override
+	public String getId() {
+		return PROVIDER_ID;
+	}
+
+}

scheduled-task/src/main/java/dasniko/keycloak/timer/ScheduledTaskProvider.java

@@ -0,0 +1,14 @@
+package dasniko.keycloak.timer;
+
+import org.keycloak.provider.Provider;
+import org.keycloak.timer.ScheduledTask;
+
+public interface ScheduledTaskProvider extends Provider {
+
+	ScheduledTask getScheduledTask();
+
+	@Override
+	default void close() {
+	}
+
+}

scheduled-task/src/main/java/dasniko/keycloak/timer/ScheduledTaskProviderFactory.java

@@ -0,0 +1,56 @@
+package dasniko.keycloak.timer;
+
+import lombok.extern.slf4j.Slf4j;
+import org.keycloak.Config;
+import org.keycloak.models.KeycloakSession;
+import org.keycloak.models.KeycloakSessionFactory;
+import org.keycloak.models.utils.PostMigrationEvent;
+import org.keycloak.provider.ProviderFactory;
+import org.keycloak.timer.TimerProvider;
+
+@Slf4j
+public abstract class ScheduledTaskProviderFactory implements ProviderFactory<ScheduledTaskProvider> {
+
+	protected static int intervalSeconds = -1;
+
+	protected static final String CONFIG_INTERVAL_SECONDS = "intervalSeconds";
+	protected static final int CONFIG_INTERVAL_SECONDS_DEFAULT = -1;
+
+	private KeycloakSessionFactory keycloakSessionFactory;
+
+	@Override
+	public void init(Config.Scope config) {
+		intervalSeconds = config.getInt(CONFIG_INTERVAL_SECONDS, CONFIG_INTERVAL_SECONDS_DEFAULT);
+	}
+
+	@Override
+	public final void postInit(KeycloakSessionFactory keycloakSessionFactory) {
+		this.keycloakSessionFactory = keycloakSessionFactory;
+
+		if (intervalSeconds <= 0) {
+			log.info("Scheduled task {} provider is disabled.", getId());
+			return;
+		};
+
+		keycloakSessionFactory.register((event) -> {
+			if (event instanceof PostMigrationEvent) {
+				KeycloakSession session = keycloakSessionFactory.create();
+				TimerProvider provider = session.getProvider(TimerProvider.class);
+				ScheduledTaskProvider stp = create(session);
+				provider.scheduleTask(stp.getScheduledTask(), getInterval(), getId());
+			}
+		});
+	}
+
+	@Override
+	public final void close() {
+		try (KeycloakSession session = keycloakSessionFactory.create()) {
+			session.getProvider(TimerProvider.class).cancelTask(getId());
+		}
+	}
+
+	protected int getInterval() {
+		return intervalSeconds * 1000;
+	}
+
+}

scheduled-task/src/main/java/dasniko/keycloak/timer/ScheduledTaskSpi.java

@@ -0,0 +1,29 @@
+package dasniko.keycloak.timer;
+
+import com.google.auto.service.AutoService;
+import org.keycloak.provider.Provider;
+import org.keycloak.provider.ProviderFactory;
+import org.keycloak.provider.Spi;
+
+@AutoService(Spi.class)
+public class ScheduledTaskSpi implements Spi {
+	@Override
+	public boolean isInternal() {
+		return true;
+	}
+
+	@Override
+	public String getName() {
+		return "scheduled-task";
+	}
+
+	@Override
+	public Class<? extends Provider> getProviderClass() {
+		return ScheduledTaskProvider.class;
+	}
+
+	@Override
+	public Class<? extends ProviderFactory<ScheduledTaskProvider>> getProviderFactoryClass() {
+		return ScheduledTaskProviderFactory.class;
+	}
+}