Feature/kafka example

components/approval/backend/src/main/kotlin/io/holunda/polyflow/example/process/approval/service/SystemInfoPrinter.kt

@@ -8,6 +8,7 @@ import io.holunda.polyflow.view.query.process.ProcessInstancesByStateQuery
 import mu.KLogging
 import org.axonframework.queryhandling.QueryGateway
 import org.springframework.boot.ApplicationRunner
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty
 import org.springframework.context.annotation.Bean
 import org.springframework.context.annotation.Configuration
 
@@ -47,6 +48,7 @@ class SystemInfoPrinter(
     }
   }
 
+  @ConditionalOnProperty(value = ["axon.axonserver.enabled"], havingValue = "true", matchIfMissing = false)
   @Bean
   fun processInstancePrinter(): ApplicationRunner {
     return ApplicationRunner {

scenarios/distributed-kafka/docker-compose.yml

@@ -0,0 +1,65 @@
+# Use this only in dev environments. It's not intended for production usage.
+version: '3.9'
+services:
+  zookeeper:
+    image: confluentinc/cp-zookeeper:latest
+    environment:
+      ZOOKEEPER_CLIENT_PORT: 2181
+      ZOOKEEPER_TICK_TIME: 2000
+    ports:
+      - '22181:2181'
+
+  kafka:
+    image: confluentinc/cp-kafka:latest
+    depends_on:
+      - zookeeper
+    ports:
+      - '9092:9092'
+      - '29092:29092'
+    environment:
+      KAFKA_BROKER_ID: 1
+      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
+      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://kafka:9092,PLAINTEXT_HOST://localhost:29092
+      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
+      KAFKA_INTER_BROKER_LISTENER_NAME: PLAINTEXT
+      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
+
+  init-kafka:
+    image: confluentinc/cp-kafka:latest
+    depends_on:
+      - kafka
+    entrypoint: [ '/bin/bash', '-c' ]
+    command: |
+      "
+      # blocks until kafka is reachable
+      echo -e 'Currently available topics:'
+      kafka-topics --bootstrap-server kafka:9092 --list
+
+      echo -e 'Creating kafka topics...'
+      kafka-topics --bootstrap-server kafka:9092 --create --if-not-exists --topic polyflow-task --replication-factor 1 --partitions 1
+      kafka-topics --bootstrap-server kafka:9092 --create --if-not-exists --topic polyflow-data --replication-factor 1 --partitions 1
+
+      echo -e 'Resulting topics:'
+      kafka-topics --bootstrap-server kafka:9092 --list
+      "
+
+  postgres-engine:
+    image: postgres:13.2
+    container_name: postgres-engine
+    environment:
+      POSTGRES_USER: polyflow_user
+      POSTGRES_PASSWORD: S3Cr3T!
+      POSTGRES_DB: enginedb
+    ports:
+      - '25433:5432'
+
+  postgres-tasklist:
+    image: postgres:13.2
+    container_name: postgres-tasklist
+    environment:
+      POSTGRES_USER: polyflow_user
+      POSTGRES_PASSWORD: S3Cr3T!
+      POSTGRES_DB: tasklistdb
+    ports:
+      - '25432:5432'
+

scenarios/distributed-kafka/pom.xml

@@ -0,0 +1,38 @@
+<?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>io.holunda.polyflow</groupId>
+    <artifactId>polyflow-example-scenario-root</artifactId>
+    <version>3.8.3-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>polyflow-example-scenario-distributed-kafka</artifactId>
+  <name>POM: examples/${project.artifactId}</name>
+  <packaging>pom</packaging>
+
+  <properties>
+    <maven.deploy.skip>true</maven.deploy.skip>
+  </properties>
+
+  <modules>
+    <module>process-application-local-polyflow</module>
+    <module>process-platform-view-only</module>
+  </modules>
+
+  <dependencyManagement>
+    <dependencies>
+
+      <dependency>
+        <groupId>org.axonframework.extensions.kafka</groupId>
+        <artifactId>axon-kafka-spring-boot-starter</artifactId>
+        <version>4.6.0</version>
+      </dependency>
+
+    </dependencies>
+
+  </dependencyManagement>
+
+</project>

scenarios/distributed-kafka/process-application-local-polyflow/pom.xml

@@ -0,0 +1,144 @@
+<?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>io.holunda.polyflow</groupId>
+    <artifactId>polyflow-example-scenario-distributed-kafka</artifactId>
+    <version>3.8.3-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>example-distributed-kafka-process-application-local-polyflow</artifactId>
+  <name>examples/${project.artifactId}</name>
+
+  <properties>
+    <maven.deploy.skip>true</maven.deploy.skip>
+  </properties>
+
+  <dependencies>
+
+    <dependency>
+      <groupId>io.holunda.polyflow</groupId>
+      <artifactId>polyflow-example-approval-backend</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>io.holunda.polyflow</groupId>
+      <artifactId>polyflow-taskpool-core</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>io.holunda.polyflow</groupId>
+      <artifactId>polyflow-datapool-core</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>io.holunda.polyflow</groupId>
+      <artifactId>polyflow-bus-jackson</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>io.holunda.polyflow</groupId>
+      <artifactId>polyflow-camunda-bpm-taskpool-job-sender</artifactId>
+    </dependency>
+
+    <!-- Kafka -->
+    <dependency>
+      <groupId>org.axonframework.extensions.kafka</groupId>
+      <artifactId>axon-kafka-spring-boot-starter</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.kafka</groupId>
+      <artifactId>kafka-clients</artifactId>
+    </dependency>
+
+    <!-- DB and Flyway -->
+    <dependency>
+      <groupId>org.postgresql</groupId>
+      <artifactId>postgresql</artifactId>
+      <scope>runtime</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.flywaydb</groupId>
+      <artifactId>flyway-core</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>io.holunda</groupId>
+      <artifactId>camunda-platform-7-autologin</artifactId>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <!-- kotlin compiler -->
+        <artifactId>kotlin-maven-plugin</artifactId>
+        <groupId>org.jetbrains.kotlin</groupId>
+      </plugin>
+      <!-- java compiler -->
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+      </plugin>
+      <plugin>
+        <!-- for packaging springboot application -->
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
+        <configuration>
+          <requiresUnpack>
+            <dependency>
+              <groupId>io.holunda.polyflow</groupId>
+              <artifactId>polyflow-example-approval-backend</artifactId>
+            </dependency>
+          </requiresUnpack>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+
+  <profiles>
+    <profile>
+      <id>frontend</id>
+      <activation>
+        <property>
+          <name>!skipFrontend</name>
+        </property>
+      </activation>
+      <dependencies>
+        <dependency>
+          <groupId>io.holunda.polyflow</groupId>
+          <artifactId>polyflow-example-approval-forms</artifactId>
+        </dependency>
+      </dependencies>
+    </profile>
+
+    <profile>
+      <id>camunda-ce</id>
+      <activation>
+        <property>
+          <name>!camunda-ee</name>
+        </property>
+      </activation>
+      <dependencies>
+        <dependency>
+          <groupId>org.camunda.bpm.springboot</groupId>
+          <artifactId>camunda-bpm-spring-boot-starter-webapp</artifactId>
+        </dependency>
+      </dependencies>
+    </profile>
+    <profile>
+      <id>camunda-ee</id>
+      <activation>
+        <property>
+          <name>camunda-ee</name>
+        </property>
+      </activation>
+      <dependencies>
+        <dependency>
+          <groupId>org.camunda.bpm.springboot</groupId>
+          <artifactId>camunda-bpm-spring-boot-starter-webapp-ee</artifactId>
+        </dependency>
+      </dependencies>
+    </profile>
+  </profiles>
+
+</project>

scenarios/distributed-kafka/process-application-local-polyflow/src/main/kotlin/io/holunda/polyflow/example/process/approval/ExampleProcessApplicationLocalPolyflowDistributedWithKafka.kt

@@ -0,0 +1,74 @@
+package io.holunda.polyflow.example.process.approval
+
+import com.fasterxml.jackson.databind.DeserializationFeature
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.SerializationFeature
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.module.kotlin.registerKotlinModule
+import io.holunda.polyflow.bus.jackson.ObjectMapperConfigurationHelper
+import io.holunda.polyflow.bus.jackson.config.FallbackPayloadObjectMapperAutoConfiguration
+import io.holunda.polyflow.bus.jackson.configurePolyflowJacksonObjectMapper
+import io.holunda.polyflow.datapool.core.EnablePolyflowDataPool
+import io.holunda.polyflow.example.process.approval.RequestApprovalProcessConfiguration
+import io.holunda.polyflow.taskpool.core.EnablePolyflowTaskPool
+import org.axonframework.eventhandling.deadletter.jpa.DeadLetterEventEntry
+import org.axonframework.eventhandling.tokenstore.jpa.TokenEntry
+import org.axonframework.eventsourcing.eventstore.jpa.DomainEventEntry
+import org.axonframework.eventsourcing.eventstore.jpa.SnapshotEventEntry
+import org.axonframework.modelling.saga.repository.jpa.SagaEntry
+import org.springframework.beans.factory.annotation.Qualifier
+import org.springframework.boot.SpringApplication
+import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.boot.autoconfigure.domain.EntityScan
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Import
+import org.springframework.context.annotation.Primary
+
+/**
+ * Starts example application approval process.
+ */
+fun main(args: Array<String>) {
+  SpringApplication.run(ExampleProcessApplicationLocalPolyflowDistributedWithKafka::class.java, *args)
+}
+
+/**
+ * Process application approval only.
+ * Includes:
+ *  - approval-process-backend
+ *  - taskpool-core
+ *  - datapool-core
+ */
+@SpringBootApplication
+@EnablePolyflowDataPool
+@EnablePolyflowTaskPool
+@Import(RequestApprovalProcessConfiguration::class)
+@EntityScan(
+  basePackageClasses = [
+    TokenEntry::class,
+    SagaEntry::class,
+    DeadLetterEventEntry::class,
+    DomainEventEntry::class,
+    SnapshotEventEntry::class
+  ]
+)
+class ExampleProcessApplicationLocalPolyflowDistributedWithKafka {
+
+  @Qualifier(FallbackPayloadObjectMapperAutoConfiguration.PAYLOAD_OBJECT_MAPPER)
+  @Bean
+  @Primary
+  fun objectMapper(): ObjectMapper =
+    jacksonObjectMapper()
+      .registerModule(JavaTimeModule())
+      .configurePolyflowJacksonObjectMapper()
+      .disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
+
+  @Bean("defaultAxonObjectMapper")
+  @Qualifier("defaultAxonObjectMapper")
+  fun defaultAxonObjectMapper(): ObjectMapper =
+    jacksonObjectMapper()
+      .registerModule(JavaTimeModule())
+      .configurePolyflowJacksonObjectMapper()
+      .disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
+
+}

scenarios/distributed-kafka/process-application-local-polyflow/src/main/kotlin/io/holunda/polyflow/example/process/approval/infrastructure/NoToastPostgresSQLDialect.kt

@@ -0,0 +1,18 @@
+package io.holunda.polyflow.example.process.approval.infrastructure
+
+import org.hibernate.dialect.PostgreSQL94Dialect
+import org.hibernate.type.descriptor.sql.BinaryTypeDescriptor
+import org.hibernate.type.descriptor.sql.SqlTypeDescriptor
+import java.sql.Types
+
+class NoToastPostgresSQLDialect : PostgreSQL94Dialect() {
+  init {
+    this.registerColumnType(Types.BLOB, "BYTEA")
+  }
+
+  override fun remapSqlTypeDescriptor(sqlTypeDescriptor: SqlTypeDescriptor): SqlTypeDescriptor {
+    return if (sqlTypeDescriptor.sqlType == Types.BLOB) {
+      BinaryTypeDescriptor.INSTANCE
+    } else super.remapSqlTypeDescriptor(sqlTypeDescriptor)
+  }
+}

scenarios/distributed-kafka/process-application-local-polyflow/src/main/kotlin/io/holunda/polyflow/example/process/approval/kafka/KafkaTopicRouter.kt

@@ -0,0 +1,16 @@
+package io.holunda.polyflow.example.process.approval.kafka
+
+import javax.validation.constraints.NotNull
+
+/**
+ * Router to decide where to publish events to.
+ */
+fun interface KafkaTopicRouter {
+    /**
+     * Retrieves the topic name for given payload type.
+     *
+     * @param payloadType payload type.
+     * @return topic or null, if the event should be dropped.
+     */
+    fun topicForPayloadType(payloadType: @NotNull Class<*>): String?
+}