Support running Yarn with JDK 17 (#305)

Hadoop is using some older dependencies that still require access to
internal JDK features so this enables that by adding JVM args

See apache/accumulo#5139

bin/impl/install/hadoop.sh

@@ -63,5 +63,16 @@ $SED "s#YARN_NM_CPU_VCORES#$YARN_NM_CPU_VCORES#g" "$hadoop_conf/yarn-site.xml"
 } >> "$hadoop_conf/hadoop-env.sh"
 [[ $HADOOP_VERSION =~ ^2\..*$ ]] && echo "export YARN_LOG_DIR=$HADOOP_LOG_DIR" >> "$hadoop_conf/yarn-env.sh"
 
+# Yarn requires extra JVM args to start with Java 17+
+jver=$("$JAVA_HOME"/bin/java -version 2>&1 | grep version | cut -f2 -d'"' | cut -f1 -d.)
+
+if [[ $jver -gt 11 ]]; then
+  echo "Setting yarn JVM args for java $jver"
+  {
+    echo "export YARN_RESOURCEMANAGER_OPTS=\"--add-opens java.base/java.lang=ALL-UNNAMED\""
+    echo "export YARN_NODEMANAGER_OPTS=\"--add-opens java.base/java.lang=ALL-UNNAMED\""
+  } >> "$hadoop_conf/yarn-env.sh"
+fi
+
 true
 # hadoop.sh

bin/impl/run/hadoop.sh

@@ -27,13 +27,7 @@ trap 'echo "[ERROR] Error occurred at $BASH_SOURCE:$LINENO command: $BASH_COMMAN
 
 "$HADOOP_HOME"/bin/hdfs namenode -format
 "$HADOOP_HOME"/sbin/start-dfs.sh
-# Yarn won't start on newer versions of Java
-jver=$("$JAVA_HOME"/bin/java -version 2>&1 | grep version | cut -f2 -d'"' | cut -f1 -d.)
-if [[ $jver -gt 11 ]]; then
-  echo "Skipping yarn because it doesn't start on Java $jver"
-else
-  "$HADOOP_HOME"/sbin/start-yarn.sh
-fi
+"$HADOOP_HOME"/sbin/start-yarn.sh
 
 namenode_port=9870
 if [[ $HADOOP_VERSION =~ ^2\..*$ ]]; then