[MESOS-7968] Handle `/proc/self/ns/pid_for_children` when parsing available namespace.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.2.3, 1.3.2, 1.4.1, 1.5.0
• Fix Version/s: 1.2.3, 1.3.2, 1.4.1, 1.5.0
• Sprint: Mesosphere Sprint 63
• Story Points: 1
• Assignee: Kapil Arya
• Reporter: Kapil Arya
• Created: 12/Sep/17 18:01
• Updated: 14/Dec/17 21:28
• Resolved: 13/Sep/17 19:38

Description

Since Linux 4.12, /proc/self/ns/pid_for_children is a handle for the PID namespace of child processes created by this process. Since this is not a namespace type in its own, we should ignore this file when listing namespaces via `ls /proc/self/ns`.