[WIP] [SPARK-3996]: Shade Jetty in Spark deliverables

This patch piggy-back's on vanzin's work to simplify the Guava shading,
and adds Jetty as a shaded library in Spark. Other than adding Jetty,
it consilidates the \<artifactSet\>'s into the root pom. I found it was
a bit easier to follow that way, since you don't need to look into
child pom's to find out specific artifact sets included in shading.

Author: Patrick Wendell <patrick@databricks.com>

Closes #4252 from pwendell/jetty and squashes the following commits:

19f0710 [Patrick Wendell] More code review feedback
961452d [Patrick Wendell] Responding to feedback from Marcello
6df25ca [Patrick Wendell] [WIP] [SPARK-3996]: Shade Jetty in Spark deliverables

bin/compute-classpath.sh

@@ -50,8 +50,8 @@ fi
 if [ -n "$SPARK_PREPEND_CLASSES" ]; then
   echo "NOTE: SPARK_PREPEND_CLASSES is set, placing locally compiled Spark"\
     "classes ahead of assembly." >&2
+  # Spark classes
   CLASSPATH="$CLASSPATH:$FWDIR/core/target/scala-$SPARK_SCALA_VERSION/classes"
-  CLASSPATH="$CLASSPATH:$FWDIR/core/target/jars/*"
   CLASSPATH="$CLASSPATH:$FWDIR/repl/target/scala-$SPARK_SCALA_VERSION/classes"
   CLASSPATH="$CLASSPATH:$FWDIR/mllib/target/scala-$SPARK_SCALA_VERSION/classes"
   CLASSPATH="$CLASSPATH:$FWDIR/bagel/target/scala-$SPARK_SCALA_VERSION/classes"
@@ -63,6 +63,8 @@ if [ -n "$SPARK_PREPEND_CLASSES" ]; then
   CLASSPATH="$CLASSPATH:$FWDIR/sql/hive/target/scala-$SPARK_SCALA_VERSION/classes"
   CLASSPATH="$CLASSPATH:$FWDIR/sql/hive-thriftserver/target/scala-$SPARK_SCALA_VERSION/classes"
   CLASSPATH="$CLASSPATH:$FWDIR/yarn/stable/target/scala-$SPARK_SCALA_VERSION/classes"
+  # Jars for shaded deps in their original form (copied here during build)
+  CLASSPATH="$CLASSPATH:$FWDIR/core/target/jars/*"
 fi
 
 # Use spark-assembly jar from either RELEASE or assembly directory

core/pom.xml

@@ -94,22 +94,35 @@
       <groupId>org.apache.curator</groupId>
       <artifactId>curator-recipes</artifactId>
     </dependency>
+
+    <!-- Jetty dependencies promoted to compile here so they are shaded
+         and inlined into spark-core jar -->
     <dependency>
       <groupId>org.eclipse.jetty</groupId>
       <artifactId>jetty-plus</artifactId>
+      <scope>compile</scope>
     </dependency>
     <dependency>
       <groupId>org.eclipse.jetty</groupId>
       <artifactId>jetty-security</artifactId>
+      <scope>compile</scope>
     </dependency>
     <dependency>
       <groupId>org.eclipse.jetty</groupId>
       <artifactId>jetty-util</artifactId>
+      <scope>compile</scope>
     </dependency>
     <dependency>
       <groupId>org.eclipse.jetty</groupId>
       <artifactId>jetty-server</artifactId>
+      <scope>compile</scope>
     </dependency>
+    <dependency>
+      <groupId>org.eclipse.jetty</groupId>
+      <artifactId>jetty-http</artifactId>
+      <scope>compile</scope>
+    </dependency>
+
     <dependency>
       <groupId>org.apache.commons</groupId>
       <artifactId>commons-lang3</artifactId>
@@ -348,19 +361,24 @@
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-dependency-plugin</artifactId>
         <executions>
+          <!-- When using SPARK_PREPEND_CLASSES Spark classes compiled locally don't use
+               shaded deps. So here we store jars in their original form which are added
+               when the classpath is computed. -->
           <execution>
             <id>copy-dependencies</id>
             <phase>package</phase>
             <goals>
               <goal>copy-dependencies</goal>
             </goals>
-            <configuration>
+           <configuration>
               <outputDirectory>${project.build.directory}</outputDirectory>
               <overWriteReleases>false</overWriteReleases>
               <overWriteSnapshots>false</overWriteSnapshots>
               <overWriteIfNewer>true</overWriteIfNewer>
               <useSubDirectoryPerType>true</useSubDirectoryPerType>
-              <includeArtifactIds>guava</includeArtifactIds>
+              <includeArtifactIds>
+                guava,jetty-io,jetty-http,jetty-plus,jetty-util,jetty-server
+              </includeArtifactIds>
               <silent>true</silent>
             </configuration>
           </execution>

network/common/pom.xml

@@ -101,18 +101,6 @@
           </execution>
         </executions>
       </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-shade-plugin</artifactId>
-        <configuration>
-          <shadedArtifactAttached>false</shadedArtifactAttached>
-          <artifactSet>
-            <includes>
-              <include>com.google.guava:guava</include>
-            </includes>
-          </artifactSet>
-        </configuration>
-      </plugin>
     </plugins>
   </build>
 </project>

pom.xml

@@ -337,25 +337,39 @@
           </exclusion>
         </exclusions>
       </dependency>
+ 
+      <!-- Shaded deps marked as provided. These are promoted to compile scope
+           in the modules where we want the shaded classes to appear in the
+           associated jar. -->
+      <dependency>
+        <groupId>org.eclipse.jetty</groupId>
+        <artifactId>jetty-http</artifactId>
+        <version>${jetty.version}</version>
+        <scope>provided</scope>
+      </dependency>
       <dependency>
         <groupId>org.eclipse.jetty</groupId>
         <artifactId>jetty-util</artifactId>
         <version>${jetty.version}</version>
+        <scope>provided</scope>
       </dependency>
       <dependency>
         <groupId>org.eclipse.jetty</groupId>
         <artifactId>jetty-security</artifactId>
         <version>${jetty.version}</version>
+        <scope>provided</scope>
       </dependency>
       <dependency>
         <groupId>org.eclipse.jetty</groupId>
         <artifactId>jetty-plus</artifactId>
         <version>${jetty.version}</version>
+        <scope>provided</scope>
       </dependency>
       <dependency>
         <groupId>org.eclipse.jetty</groupId>
         <artifactId>jetty-server</artifactId>
         <version>${jetty.version}</version>
+        <scope>provided</scope>
       </dependency>
       <dependency>
         <groupId>com.google.guava</groupId>
@@ -363,6 +377,8 @@
         <version>14.0.1</version>
         <scope>provided</scope>
       </dependency>
+      <!-- End of shaded deps -->
+ 
       <dependency>
         <groupId>org.apache.commons</groupId>
         <artifactId>commons-lang3</artifactId>
@@ -1276,10 +1292,26 @@
           <shadedArtifactAttached>false</shadedArtifactAttached>
           <artifactSet>
             <includes>
+              <!-- At a minimum we must include this to force effective pom generation -->
               <include>org.spark-project.spark:unused</include>
+
+              <include>org.eclipse.jetty:jetty-io</include>
+              <include>org.eclipse.jetty:jetty-http</include>
+              <include>org.eclipse.jetty:jetty-plus</include>
+              <include>org.eclipse.jetty:jetty-security</include>
+              <include>org.eclipse.jetty:jetty-util</include>
+              <include>org.eclipse.jetty:jetty-server</include>
+              <include>com.google.guava:guava</include>
             </includes>
           </artifactSet>
           <relocations>
+            <relocation>
+              <pattern>org.eclipse.jetty</pattern>
+              <shadedPattern>org.spark-project.jetty</shadedPattern>
+              <includes>
+                <include>org.eclipse.jetty.**</include>
+              </includes>
+            </relocation>
             <relocation>
               <pattern>com.google.common</pattern>
               <shadedPattern>org.spark-project.guava</shadedPattern>