[MESOS-4609] Subprocess should be more intelligent about setting/inheriting libprocess environment variables

• Type: Bug
• Status: Accepted
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.27.0
• Component/s: libprocess
• Labels: mesosphere
• Target Version/s: 0.28.0
• Epic Link: logger module
• Sprint: Mesosphere Sprint 28
• Story Points: 2
• Assignee: Unassigned
• Reporter: Joseph Wu
• Created: 05/Feb/16 18:21
• Updated: 26/Nov/18 13:36

Description

Mostly copied from this comment

A subprocess inheriting the environment variables LIBPROCESS_* may run into some accidental fatalities:

	Subprocess uses libprocess	Subprocess is something else
Subprocess sets/inherits the same PORT by accident	Bind failure -> exit	Nothing happens
Subprocess sets a different PORT on purpose	Bind success	Nothing happens

= means this is usually the case, but not 100%.

A complete fix would look something like:

• If the subprocess call gets environment = None(), we should automatically remove LIBPROCESS_PORT from the inherited environment.
• The parts of executorEnvironment dealing with libprocess & libmesos should be refactored into libprocess as a helper. We would use this helper for the Containerizer, Fetcher, and ContainerLogger module.
• If the subprocess call is given LIBPROCESS_PORT == os::getenv("LIBPROCESS_PORT"), we can LOG(WARN) and unset the env var locally.

Issue Links

• is a clone of: MESOS-4598 Logrotate ContainerLogger should not remove IP from environment.
• is related to: MESOS-4585 mesos-fetcher LIBPROCESS_PORT set to 5051 URI fetch failure
• relates to: MESOS-4601 Don't dump stack trace on failure to bind()
• relates to: MESOS-4353 Limit the number of processes created by libprocess