SAMZA-2653: Write pathing jar of run-class.sh into its own directory (#1498)

Issue: Currently, the pathing.jar file used to specify the classpath for run-class.sh is written directly into the top-level working directory of the app. When using container images, there may be some predefined permissions set on the working directory. This may cause permission issues with being able to write the pathing.jar file.

Changes: Create a separate directory for writing classpath-related files (manifest.txt, pathing.jar) and write the pathing.jar to that separate directory. Update the classpath arguments to use the new location of the pathing.jar.

API changes, usage/upgrade instructions: N/A

See #1498 for more context about a use case for this change.

Author: cameronlee314

samza-shell/src/main/bash/run-class.sh

@@ -68,10 +68,21 @@ else
   JAR="$JAVA_HOME/bin/jar"
 fi
 
+# Create a separate directory for writing files related to classpath management. It is easier to manage
+# permissions for the classpath-related files when they are in their own directory. An example of where
+# this is helpful is when using container images which might have predefined permissions for certain
+# directories.
+CLASSPATH_WORKSPACE_DIR=$base_dir/classpath_workspace
+mkdir -p $CLASSPATH_WORKSPACE_DIR
+# file containing the classpath string; used to avoid passing long classpaths directly to the jar command
+PATHING_MANIFEST_FILE=$CLASSPATH_WORKSPACE_DIR/manifest.txt
+# jar file to include on the classpath for running the main class
+PATHING_JAR_FILE=$CLASSPATH_WORKSPACE_DIR/pathing.jar
+
 # Newlines and spaces are intended to ensure proper parsing of manifest in pathing jar
-printf "Class-Path: \n $CLASSPATH \n" > manifest.txt
+printf "Class-Path: \n $CLASSPATH \n" > $PATHING_MANIFEST_FILE
 # Creates a new archive and adds custom manifest information to pathing.jar
-eval "$JAR -cvmf manifest.txt pathing.jar"
+eval "$JAR -cvmf $PATHING_MANIFEST_FILE $PATHING_JAR_FILE"
 
 if [ -z "$JAVA_HOME" ]; then
   JAVA="java"
@@ -151,11 +162,11 @@ fi
 [[ $JAVA_OPTS != *-d64* ]] && check_and_enable_64_bit_mode
 
 # HADOOP_CONF_DIR should be supplied to classpath explicitly for Yarn to parse configs
-echo $JAVA $JAVA_OPTS -cp $HADOOP_CONF_DIR:pathing.jar "$@"
+echo $JAVA $JAVA_OPTS -cp $HADOOP_CONF_DIR:$PATHING_JAR_FILE "$@"
 
 ## If localized resource lib directory is defined, then include it in the classpath.
 if [[ -z "${ADDITIONAL_CLASSPATH_DIR}" ]]; then
-  exec $JAVA $JAVA_OPTS -cp $HADOOP_CONF_DIR:pathing.jar "$@"
+  exec $JAVA $JAVA_OPTS -cp $HADOOP_CONF_DIR:$PATHING_JAR_FILE "$@"
 else
-  exec $JAVA $JAVA_OPTS -cp $HADOOP_CONF_DIR:pathing.jar:$ADDITIONAL_CLASSPATH_DIR "$@"
+  exec $JAVA $JAVA_OPTS -cp $HADOOP_CONF_DIR:$PATHING_JAR_FILE:$ADDITIONAL_CLASSPATH_DIR "$@"
 fi