feat(worker): context is available for scripting

* the context contains the current job and the Zeebe client * get rid of Spring Boot
camunda-community-hub · Dec 21, 2018 · 56ab5a9 · 56ab5a9
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diff --git a/README.md b/README.md
@@ -1,20 +1,21 @@
 # zeebe-script-worker
 
-This is a Zeebe worker to evaluate scripts. Scripts are useful to create/modify the payload, to do (simple) calculations or for prototyping.
+A Zeebe worker to evaluate scripts. Scripts are useful to create/modify the payload, to do (simple) calculations or for prototyping.
 
 * the worker is registered for the type `script`
 * required custom headers:
   * `language` (String) - the name of the script language
   * `script` (String) - the script to evaluate
 * output payload contains `result` - the result of the evaluation   
+* available context in script:
+  * `job` (ActivatedJob) - the current job
+  * `zeebeClient` (ZeebeClient) - the client of the worker
 
 Available script languages:
 * javascript (Oracle Nashorn)
 * [groovy](http://groovy-lang.org/)
 * [feel](https://github.com/camunda/feel-scala)
 
-_This is a community project meant for playing around with Zeebe. It is not officially supported by the Zeebe Team (i.e. no gurantees). Everybody is invited to contribute!_
-
 ## Usage
 
 The service task:
@@ -55,11 +56,9 @@ Execute the JAR file via
 
 ## How to configure
 
-The worker can be configured via environment variables or a properties file `application.properties`.
+You can set the following environment variables to configure the worker.
 
-```
-zeebe.client.broker.contactPoint=127.0.0.1:26500
-```
+* `zeebe.client.broker.contactPoint`- default: `127.0.0.1:26500`
 
 ## Examples
 Some examples for common use cases:

diff --git a/pom.xml b/pom.xml
@@ -1,4 +1,6 @@
-<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">
+<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>
 	<name>Zeebe Script Worker</name>
@@ -38,13 +40,6 @@
 				<scope>import</scope>
 				<type>pom</type>
 			</dependency>
-			<dependency>
-				<groupId>org.springframework.boot</groupId>
-				<artifactId>spring-boot-dependencies</artifactId>
-				<version>2.0.3.RELEASE</version>
-				<type>pom</type>
-				<scope>import</scope>
-			</dependency>
 		</dependencies>
 	</dependencyManagement>
 
@@ -55,11 +50,6 @@
 			<artifactId>zeebe-client-java</artifactId>
 		</dependency>
 
-		<dependency>
-			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter</artifactId>
-		</dependency>
-
 		<!-- script languages -->
 		<dependency>
 			<groupId>org.codehaus.groovy</groupId>
@@ -73,11 +63,25 @@
 			<version>${version.feel}</version>
 		</dependency>
 
+		<!-- logging -->
+		<dependency>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-core</artifactId>
+			<version>2.11.1</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.apache.logging.log4j</groupId>
+			<artifactId>log4j-slf4j-impl</artifactId>
+			<version>2.11.1</version>
+		</dependency>
+
 		<!-- test -->
 		<dependency>
 			<groupId>junit</groupId>
 			<artifactId>junit</artifactId>
 			<scope>test</scope>
+			<version>4.12</version>
 		</dependency>
 
 		<dependency>
@@ -87,25 +91,43 @@
 			<scope>test</scope>
 		</dependency>
 
+		<dependency>
+			<groupId>io.zeebe</groupId>
+			<artifactId>zeebe-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+
 	</dependencies>
 
 	<build>
 		<plugins>
 			<plugin>
-				<groupId>org.springframework.boot</groupId>
-				<artifactId>spring-boot-maven-plugin</artifactId>
-				<version>2.0.3.RELEASE</version>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<configuration>
+					<descriptorRefs>
+						<descriptorRef>jar-with-dependencies</descriptorRef>
+					</descriptorRefs>
+					<archive>
+						<manifest>
+							<mainClass>io.zeebe.script.ZeebeScriptWorkerApplication</mainClass>
+						</manifest>
+					</archive>
+					<finalName>${project.artifactId}-${project.version}</finalName>
+					<appendAssemblyId>false</appendAssemblyId>
+				</configuration>
 				<executions>
 					<execution>
+						<id>make-assembly</id>
+						<phase>package</phase>
 						<goals>
-							<goal>repackage</goal>
+							<goal>single</goal>
 						</goals>
 					</execution>
 				</executions>
 			</plugin>
 		</plugins>
 	</build>
-	
+
 	<repositories>
 		<repository>
 			<id>zeebe</id>

diff --git a/src/main/java/io/zeebe/script/ScriptEvaluator.java b/src/main/java/io/zeebe/script/ScriptEvaluator.java
@@ -22,9 +22,7 @@
 import javax.script.ScriptEngine;
 import javax.script.ScriptEngineManager;
 import javax.script.ScriptException;
-import org.springframework.stereotype.Component;
 
-@Component
 public class ScriptEvaluator {
 
   private final ScriptEngineManager scriptEngineManager = new ScriptEngineManager();

diff --git a/src/main/java/io/zeebe/script/ScriptJobHandler.java b/src/main/java/io/zeebe/script/ScriptJobHandler.java
@@ -15,34 +15,42 @@
  */
 package io.zeebe.script;
 
+import io.zeebe.client.ZeebeClient;
 import io.zeebe.client.api.clients.JobClient;
 import io.zeebe.client.api.response.ActivatedJob;
 import io.zeebe.client.api.subscription.JobHandler;
 import java.util.Collections;
 import java.util.Map;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.stereotype.Component;
 
-@Component
 public class ScriptJobHandler implements JobHandler {
 
   private static final String HEADER_LANGUAGE = "language";
   private static final String HEADER_SCRIPT = "script";
 
-  @Autowired private ScriptEvaluator scriptEvaluator;
+  private final ScriptEvaluator scriptEvaluator = new ScriptEvaluator();
+
+  private final ZeebeClient zeebeClient;
+
+  public ScriptJobHandler(ZeebeClient zeebeClient) {
+    this.zeebeClient = zeebeClient;
+  }
 
   @Override
-  public void handle(JobClient client, ActivatedJob job) {
+  public void handle(JobClient jobClient, ActivatedJob job) {
 
     final Map<String, Object> customHeaders = job.getCustomHeaders();
     final String language = getLanguage(customHeaders);
     final String script = getScript(customHeaders);
 
     final Map<String, Object> payload = job.getPayloadAsMap();
 
+    // add context
+    payload.put("job", job);
+    payload.put("zeebeClient", zeebeClient);
+
     final Object result = scriptEvaluator.evaluate(language, script, payload);
 
-    client
+    jobClient
         .newCompleteCommand(job.getKey())
         .payload(Collections.singletonMap("result", result))
         .send();
@@ -52,7 +60,7 @@ private String getLanguage(Map<String, Object> customHeaders) {
     final Object language = customHeaders.get(HEADER_LANGUAGE);
     if (language == null) {
       throw new RuntimeException(
-          String.format("Missing required custom header '%'", HEADER_LANGUAGE));
+          String.format("Missing required custom header '%s'", HEADER_LANGUAGE));
     } else {
       return String.valueOf(language);
     }
@@ -62,7 +70,7 @@ private String getScript(Map<String, Object> customHeaders) {
     final Object script = customHeaders.get(HEADER_SCRIPT);
     if (script == null) {
       throw new RuntimeException(
-          String.format("Missing required custom header '%'", HEADER_SCRIPT));
+          String.format("Missing required custom header '%s'", HEADER_SCRIPT));
     } else {
       return String.valueOf(script);
     }

diff --git a/src/main/java/io/zeebe/script/ZeebeScriptWorker.java b/src/main/java/io/zeebe/script/ZeebeScriptWorker.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright © 2017 camunda services GmbH ([email protected])
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.zeebe.script;
+
+import io.zeebe.client.ZeebeClient;
+import io.zeebe.client.api.subscription.JobWorker;
+import java.time.Duration;
+
+public class ZeebeScriptWorker {
+
+  private final String contactPoint;
+
+  private JobWorker jobWorker;
+
+  public ZeebeScriptWorker(String contactPoint) {
+    this.contactPoint = contactPoint;
+  }
+
+  public void start() {
+    final ZeebeClient client =
+        ZeebeClient.newClientBuilder()
+            .brokerContactPoint(contactPoint)
+            .defaultJobWorkerName("script-worker")
+            .defaultJobTimeout(Duration.ofSeconds(10))
+            .build();
+
+    final ScriptJobHandler jobHandler = new ScriptJobHandler(client);
+    jobWorker = client.jobClient().newWorker().jobType("script").handler(jobHandler).open();
+  }
+
+  public void stop() {
+    if (jobWorker != null) {
+      jobWorker.close();
+    }
+  }
+}
diff --git a/src/main/java/io/zeebe/script/ZeebeScriptWorkerApplication.java b/src/main/java/io/zeebe/script/ZeebeScriptWorkerApplication.java
@@ -15,36 +15,31 @@
  */
 package io.zeebe.script;
 
-import io.zeebe.client.ZeebeClient;
-import java.time.Duration;
-import javax.annotation.PostConstruct;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.beans.factory.annotation.Value;
-import org.springframework.boot.SpringApplication;
-import org.springframework.boot.autoconfigure.SpringBootApplication;
-
-@SpringBootApplication
+import java.util.Optional;
+import java.util.concurrent.CountDownLatch;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 public class ZeebeScriptWorkerApplication {
 
-  @Value("${zeebe.client.broker.contactPoint:127.0.0.1:26500}")
-  private String contactPoint;
+  public static final String ENV_CONTACT_POINT = "zeebe.client.broker.contactPoint";
+  private static final String DEFAULT_CONTACT_POINT = "127.0.0.1:26500";
 
-  @Autowired private ScriptJobHandler jobHandler;
+  private static Logger LOG = LoggerFactory.getLogger("zeebe-script-worker");
 
   public static void main(String[] args) {
-    SpringApplication.run(ZeebeScriptWorkerApplication.class, args);
-  }
 
-  @PostConstruct
-  public void start() {
+    final String contactPoint =
+        Optional.ofNullable(System.getenv(ENV_CONTACT_POINT)).orElse(DEFAULT_CONTACT_POINT);
+
+    LOG.info("Connecting worker to {}", contactPoint);
 
-    final ZeebeClient client =
-        ZeebeClient.newClientBuilder()
-            .brokerContactPoint(contactPoint)
-            .defaultJobWorkerName("script-worker")
-            .defaultJobTimeout(Duration.ofSeconds(10))
-            .build();
+    final ZeebeScriptWorker worker = new ZeebeScriptWorker(contactPoint);
+    worker.start();
 
-    client.jobClient().newWorker().jobType("script").handler(jobHandler).open();
+    try {
+      new CountDownLatch(1).await();
+    } catch (InterruptedException e) {
+    }
   }
 }
diff --git a/src/main/resources/log4j2.xml b/src/main/resources/log4j2.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+
+  <Appenders>
+    <Console name="Console" target="SYSTEM_OUT">
+      <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+    </Console>
+  </Appenders>
+
+  <Loggers>
+    <Logger name="io.zeebe" level="info"/>
+    <Logger name="io.zeebe.script" level="debug"/>
+
+    <Root level="info">
+      <AppenderRef ref="Console"/>
+    </Root>
+  </Loggers>
+
+</Configuration>