AMBARI-18642. During HDP upgrade, Ambari does not allow redirecting the /tmp/upgrade directory elsewhere (aonishuk)

ambari-server/src/main/resources/common-services/HDFS/2.1.0.2.0/configuration/hadoop-env.xml

@@ -221,6 +221,12 @@
     <description>Max number of processes limit setting for HDFS user.</description>
     <on-ambari-upgrade add="true"/>
   </property>
+  <property>
+    <name>namenode_backup_dir</name>
+    <description>Local directory for storing backup copy of NameNode images during upgrade</description>
+    <value>/tmp/upgrades</value>
+    <on-ambari-upgrade add="true"/>
+  </property>
   <property>
     <name>hdfs_user_keytab</name>
     <description>HDFS keytab path</description>

ambari-server/src/main/resources/common-services/HDFS/2.1.0.2.0/package/scripts/namenode_upgrade.py

@@ -114,7 +114,7 @@ def prepare_upgrade_backup_namenode_dir():
   i = 0
   failed_paths = []
   nn_name_dirs = params.dfs_name_dir.split(',')
-  backup_destination_root_dir = "/tmp/upgrades/{0}".format(params.stack_version_unformatted)
+  backup_destination_root_dir = "{0}/{1}".format(params.namenode_backup_dir, params.stack_version_unformatted)
   if len(nn_name_dirs) > 0:
     Logger.info("Backup the NameNode name directory's CURRENT folder.")
   for nn_dir in nn_name_dirs:

ambari-server/src/main/resources/common-services/HDFS/2.1.0.2.0/package/scripts/params_linux.py

@@ -90,6 +90,7 @@ dfs_dn_ipc_address = config['configurations']['hdfs-site']['dfs.datanode.ipc.add
 secure_dn_ports_are_in_use = False
 
 hdfs_tmp_dir = config['configurations']['hadoop-env']['hdfs_tmp_dir']
+namenode_backup_dir = default("/configurations/hadoop-env/namenode_backup_dir", "/tmp/upgrades")
 
 # hadoop default parameters
 mapreduce_libs_path = "/usr/lib/hadoop-mapreduce/*"