Github user mmiklavc commented on a diff in the pull request:
https://github.com/apache/metron/pull/785#discussion_r143549913
--- Diff:
metron-platform/metron-parsers/src/main/java/org/apache/metron/parsers/topology/MergeAndShadeTransformer.java
---
@@ -0,0 +1,90 @@
+/**
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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 org.apache.metron.parsers.topology;
+
+import com.google.common.base.Splitter;
+import org.apache.storm.daemon.JarTransformer;
+import org.apache.storm.hack.StormShadeTransformer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.*;
+import java.lang.invoke.MethodHandles;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.jar.JarEntry;
+import java.util.jar.JarInputStream;
+import java.util.jar.JarOutputStream;
+
+/**
+ * This is a storm jar transformer that will add in additional jars pulled
from an
+ * environment variable. The jars will be merged with the main uber jar
and then
+ * the resulting jar will be shaded and relocated according to the
StormShadeTransformer.
+ *
+ */
+public class MergeAndShadeTransformer implements JarTransformer {
+ public static final String EXTRA_JARS_ENV = "EXTRA_JARS";
+ private static final Logger LOG =
LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
+
+ StormShadeTransformer _underlyingTransformer = new
StormShadeTransformer();
+ @Override
+ public void transform(InputStream input, OutputStream output) throws
IOException {
+ String extraJars = System.getenv().get(EXTRA_JARS_ENV);
+ if(extraJars == null || extraJars.length() == 0) {
+ _underlyingTransformer.transform(input, output);
+ return;
+ }
+ File tmpFile = File.createTempFile("metron", "jar");
+ tmpFile.deleteOnExit();
+ Set<String> entries = new HashSet<>();
+ try (JarOutputStream jout = new JarOutputStream(new
BufferedOutputStream(new FileOutputStream(tmpFile)))) {
+ try (JarInputStream jin = new JarInputStream(new
BufferedInputStream(input))){
+ copy(jin, jout, entries);
--- End diff --
Can you document that this method has side effects on the set "entries", or
modify the method to return a modified `Set<String>` to make this more explicit?
---
