[YARN-5730] Improve setting of environment variable HOME in containers

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: nodemanager

Environment

ContainerLaunch.java

• Assignee: Unassigned
• Reporter: Markus Döring
• Created: 13/Oct/16 14:01
• Updated: 13/Oct/16 14:01

Description

Currently, the HOME environment variable for a YARN container is determined as follows[1]:

1. if the (undocumented) configuration yarn.nodemanager.user-home-dir is set, HOME is set to its value
2. otherwise, HOME is set to "/home/"

Option 1 is suboptimal in a multi-user environment, while the default does not help at all.

It would be nice if we could do one of the following:

1. default to HOME unset
2. default to "/home/" + container.getUser()
3. get HOME from container

Option 1 would at least inform the process about the problem, but would obviously cause some problems in programs that assume HOME to be set. Option 2 might point to the correct home, at least it's not more incorrect than "/home/". Option 3 might be the best choice, but it also requires API changes.