Make the maven build generate the test jar for Python MQTT tests

Author: zsxwing

external/mqtt/pom.xml

@@ -78,5 +78,33 @@
   <build>
     <outputDirectory>target/scala-${scala.binary.version}/classes</outputDirectory>
     <testOutputDirectory>target/scala-${scala.binary.version}/test-classes</testOutputDirectory>
+
+    <plugins>
+      <!-- Assemble a jar with test dependencies for Python tests -->
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>test-jar-with-dependencies</id>
+            <phase>package</phase>
+            <goals>
+              <goal>single</goal>
+            </goals>
+            <configuration>
+              <!-- Make sure the file path is same as the sbt build -->
+              <finalName>spark-streaming-mqtt-test-${project.version}</finalName>
+              <outputDirectory>${project.build.directory}/scala-${scala.binary.version}/</outputDirectory>
+              <appendAssemblyId>false</appendAssemblyId>
+              <!-- Don't publish it since it's only for Python tests -->
+              <attach>false</attach>
+              <descriptors>
+                <descriptor>src/main/assembly/assembly.xml</descriptor>
+              </descriptors>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
   </build>
 </project>

external/mqtt/src/main/assembly/assembly.xml

@@ -0,0 +1,38 @@
+<!--
+  ~ Licensed to the Apache Software Foundation (ASF) under one or more
+  ~ contributor license agreements.  See the NOTICE file distributed with
+  ~ this work for additional information regarding copyright ownership.
+  ~ The ASF licenses this file to You 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.
+  -->
+<assembly>
+  <id>test-jar-with-dependencies</id>
+  <formats>
+    <format>jar</format>
+  </formats>
+  <includeBaseDirectory>false</includeBaseDirectory>
+
+  <dependencySets>
+    <dependencySet>
+      <useTransitiveDependencies>true</useTransitiveDependencies>
+      <scope>test</scope>
+      <useProjectArtifact>false</useProjectArtifact>
+      <excludes>
+        <exclude>org.apache.hadoop:*:jar</exclude>
+        <exclude>org.apache.spark:*:jar</exclude>
+        <exclude>org.apache.zookeeper:*:jar</exclude>
+        <exclude>org.apache.avro:*:jar</exclude>
+      </excludes>
+    </dependencySet>
+  </dependencySets>
+
+</assembly>